started ropesim tool
authorJohn Tsiombikas <nuclear@member.fsf.org>
Wed, 25 Dec 2019 05:16:47 +0000 (07:16 +0200)
committerJohn Tsiombikas <nuclear@member.fsf.org>
Wed, 25 Dec 2019 05:16:47 +0000 (07:16 +0200)
.gitignore
tools/ropesim/Makefile [new file with mode: 0644]
tools/ropesim/src/cmesh.c [new file with mode: 0644]
tools/ropesim/src/cmesh.h [new file with mode: 0644]
tools/ropesim/src/main.c [new file with mode: 0644]
tools/ropesim/src/meshload.c [new file with mode: 0644]
tools/ropesim/src/opengl.h [new file with mode: 0644]

index 4aa79a5..0d8b1b8 100644 (file)
@@ -41,3 +41,5 @@ data
 tools/csprite/csprite
 cspr/
 tools/img2bin/img2bin
+tools/ropesim/ropesim
+tools/gltest/test
diff --git a/tools/ropesim/Makefile b/tools/ropesim/Makefile
new file mode 100644 (file)
index 0000000..9270553
--- /dev/null
@@ -0,0 +1,18 @@
+src = $(wildcard src/*.c)
+obj = $(src:.c=.o)
+bin = ropesim
+
+def = -DUSE_ASSIMP
+warn = -pedantic -Wall -Wno-int-to-pointer-cast
+
+CFLAGS = $(warn) -g $(def)
+LDFLAGS = $(libgl) -lm -lassimp
+
+libgl = -lGL -lGLU -lglut
+
+$(bin): $(obj)
+       $(CC) -o $@ $(obj) $(LDFLAGS)
+
+.PHONY: clean
+clean:
+       rm -f $(obj) $(bin)
diff --git a/tools/ropesim/src/cmesh.c b/tools/ropesim/src/cmesh.c
new file mode 100644 (file)
index 0000000..64ed2d0
--- /dev/null
@@ -0,0 +1,1619 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <float.h>
+#include <assert.h>
+#include "opengl.h"
+#include "cmesh.h"
+
+
+struct cmesh_vattrib {
+       int nelem;      /* num elements per attribute [1, 4] */
+       float *data;
+       unsigned int count;
+       unsigned int vbo;
+       int vbo_valid, data_valid;
+};
+
+/* istart,icount are valid only when the mesh is indexed, otherwise icount is 0.
+ * vstart,vcount are define the submesh for non-indexed meshes.
+ * For indexed meshes, vstart,vcount denote the range of vertices used by each
+ * submesh.
+ */
+struct submesh {
+       char *name;
+       int nfaces;     /* derived from either icount or vcount */
+       int istart, icount;
+       int vstart, vcount;
+       struct submesh *next;
+};
+
+struct cmesh {
+       char *name;
+       unsigned int nverts, nfaces;
+
+       struct submesh *sublist;
+       int subcount;
+
+       /* current value for each attribute for the immediate mode interface */
+       cgm_vec4 cur_val[CMESH_NUM_ATTR];
+
+       unsigned int buffer_objects[CMESH_NUM_ATTR + 1];
+       struct cmesh_vattrib vattr[CMESH_NUM_ATTR];
+
+       unsigned int *idata;
+       unsigned int icount;
+       unsigned int ibo;
+       int ibo_valid, idata_valid;
+
+       /* index buffer for wireframe rendering (constructed on demand) */
+       unsigned int wire_ibo;
+       int wire_ibo_valid;
+
+       /* axis-aligned bounding box */
+       cgm_vec3 aabb_min, aabb_max;
+       int aabb_valid;
+       /* bounding sphere */
+       cgm_vec3 bsph_center;
+       float bsph_radius;
+       int bsph_valid;
+};
+
+
+static int clone(struct cmesh *cmdest, struct cmesh *cmsrc, struct submesh *sub);
+static int pre_draw(struct cmesh *cm);
+static void post_draw(struct cmesh *cm, int cur_sdr);
+static void update_buffers(struct cmesh *cm);
+static void update_wire_ibo(struct cmesh *cm);
+static void calc_aabb(struct cmesh *cm);
+static void calc_bsph(struct cmesh *cm);
+
+static int def_nelem[CMESH_NUM_ATTR] = {3, 3, 3, 2, 4, 4, 4, 2};
+
+static int sdr_loc[CMESH_NUM_ATTR] = {0, 1, 2, 3, 4, 5, 6, 7};
+static int use_custom_sdr_attr;
+
+
+/* global state */
+void cmesh_set_attrib_sdrloc(int attr, int loc)
+{
+       sdr_loc[attr] = loc;
+}
+
+int cmesh_get_attrib_sdrloc(int attr)
+{
+       return sdr_loc[attr];
+}
+
+void cmesh_clear_attrib_sdrloc(void)
+{
+       int i;
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               sdr_loc[i] = -1;
+       }
+}
+
+/* mesh functions */
+struct cmesh *cmesh_alloc(void)
+{
+       struct cmesh *cm;
+
+       if(!(cm = malloc(sizeof *cm))) {
+               return 0;
+       }
+       if(cmesh_init(cm) == -1) {
+               free(cm);
+               return 0;
+       }
+       return cm;
+}
+
+void cmesh_free(struct cmesh *cm)
+{
+       cmesh_destroy(cm);
+       free(cm);
+}
+
+int cmesh_init(struct cmesh *cm)
+{
+       int i;
+
+       memset(cm, 0, sizeof *cm);
+       cgm_wcons(cm->cur_val + CMESH_ATTR_COLOR, 1, 1, 1, 1);
+
+       glGenBuffers(CMESH_NUM_ATTR + 1, cm->buffer_objects);
+
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               cm->vattr[i].vbo = cm->buffer_objects[i];
+       }
+
+       cm->ibo = cm->buffer_objects[CMESH_NUM_ATTR];
+       return 0;
+}
+
+void cmesh_destroy(struct cmesh *cm)
+{
+       int i;
+
+       free(cm->name);
+
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               free(cm->vattr[i].data);
+       }
+       free(cm->idata);
+
+       cmesh_clear_submeshes(cm);
+
+       glDeleteBuffers(CMESH_NUM_ATTR + 1, cm->buffer_objects);
+       if(cm->wire_ibo) {
+               glDeleteBuffers(1, &cm->wire_ibo);
+       }
+}
+
+void cmesh_clear(struct cmesh *cm)
+{
+       int i;
+
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               cm->vattr[i].nelem = 0;
+               cm->vattr[i].vbo_valid = 0;
+               cm->vattr[i].data_valid = 0;
+               free(cm->vattr[i].data);
+               cm->vattr[i].data = 0;
+               cm->vattr[i].count = 0;
+       }
+       cm->ibo_valid = cm->idata_valid = 0;
+       free(cm->idata);
+       cm->idata = 0;
+       cm->icount = 0;
+
+       cm->wire_ibo_valid = 0;
+       cm->nverts = cm->nfaces = 0;
+
+       cm->bsph_valid = cm->aabb_valid = 0;
+
+       cmesh_clear_submeshes(cm);
+}
+
+int cmesh_clone(struct cmesh *cmdest, struct cmesh *cmsrc)
+{
+       return clone(cmdest, cmsrc, 0);
+}
+
+static int clone(struct cmesh *cmdest, struct cmesh *cmsrc, struct submesh *sub)
+{
+       int i, nelem, vstart, vcount, istart, icount;
+       char *srcname, *name = 0;
+       float *varr[CMESH_NUM_ATTR] = {0};
+       float *vptr;
+       unsigned int *iptr, *iarr = 0;
+
+       /* try do anything that can fail first, before making any changes to cmdest
+        * so we have the option of recovering gracefuly
+        */
+
+       srcname = sub ? sub->name : cmsrc->name;
+       if(srcname) {
+               if(!(name = malloc(strlen(srcname) + 1))) {
+                       return -1;
+               }
+               strcpy(name, srcname);
+       }
+
+       if(sub) {
+               vstart = sub->vstart;
+               vcount = sub->vcount;
+               istart = sub->istart;
+               icount = sub->icount;
+       } else {
+               vstart = istart = 0;
+               vcount = cmsrc->nverts;
+               icount = cmsrc->icount;
+       }
+
+       if(cmesh_indexed(cmsrc)) {
+               if(!(iarr = malloc(icount * sizeof *iarr))) {
+                       free(name);
+                       return -1;
+               }
+       }
+
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               if(cmesh_has_attrib(cmsrc, i)) {
+                       nelem = cmsrc->vattr[i].nelem;
+                       if(!(varr[i] = malloc(vcount * nelem * sizeof(float)))) {
+                               while(--i >= 0) {
+                                       free(varr[i]);
+                               }
+                               free(iarr);
+                               free(name);
+                               return -1;
+                       }
+               }
+       }
+
+       /* from this point forward nothing can fail */
+       cmesh_clear(cmdest);
+
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               free(cmdest->vattr[i].data);
+
+               if(cmesh_has_attrib(cmsrc, i)) {
+                       cmesh_attrib(cmsrc, i); /* force validation of the actual data on the source mesh */
+
+                       nelem = cmsrc->vattr[i].nelem;
+                       cmdest->vattr[i].nelem = nelem;
+                       cmdest->vattr[i].data = varr[i];
+                       cmdest->vattr[i].count = vcount;
+                       vptr = cmsrc->vattr[i].data + vstart * nelem;
+                       memcpy(cmdest->vattr[i].data, vptr, vcount * nelem * sizeof(float));
+                       cmdest->vattr[i].data_valid = 1;
+                       cmdest->vattr[i].vbo_valid = 0;
+               } else {
+                       memset(cmdest->vattr + i, 0, sizeof cmdest->vattr[i]);
+               }
+       }
+
+       if(cmesh_indexed(cmsrc)) {
+               cmesh_index(cmsrc);     /* force validation .... */
+
+               cmdest->idata = iarr;
+               cmdest->icount = icount;
+               if(sub) {
+                       /* need to offset all vertex indices by -vstart */
+                       iptr = cmsrc->idata + istart;
+                       for(i=0; i<icount; i++) {
+                               cmdest->idata[i] = *iptr++ - vstart;
+                       }
+               } else {
+                       memcpy(cmdest->idata, cmsrc->idata + istart, icount * sizeof *cmdest->idata);
+               }
+               cmdest->idata_valid = 1;
+       } else {
+               cmdest->idata = 0;
+               cmdest->idata_valid = cmdest->ibo_valid = 0;
+       }
+
+       free(cmdest->name);
+       cmdest->name = name;
+
+       cmdest->nverts = cmsrc->nverts;
+       cmdest->nfaces = sub ? sub->nfaces : cmsrc->nfaces;
+
+       memcpy(cmdest->cur_val, cmsrc->cur_val, sizeof cmdest->cur_val);
+
+       cmdest->aabb_min = cmsrc->aabb_min;
+       cmdest->aabb_max = cmsrc->aabb_max;
+       cmdest->aabb_valid = cmsrc->aabb_valid;
+       cmdest->bsph_center = cmsrc->bsph_center;
+       cmdest->bsph_radius = cmsrc->bsph_radius;
+       cmdest->bsph_valid = cmsrc->bsph_valid;
+
+       /* copy sublist only if we're not cloning a submesh */
+       if(!sub) {
+               struct submesh *sm, *n, *head = 0, *tail = 0;
+
+               sm = cmsrc->sublist;
+               while(sm) {
+                       if(!(n = malloc(sizeof *n)) || !(name = malloc(strlen(sm->name) + 1))) {
+                               free(n);
+                               sm = sm->next;
+                               continue;
+                       }
+                       strcpy(name, sm->name);
+                       *n = *sm;
+                       n->name = name;
+                       n->next = 0;
+
+                       if(head) {
+                               tail->next = n;
+                               tail = n;
+                       } else {
+                               head = tail = n;
+                       }
+
+                       sm = sm->next;
+               }
+
+               cmdest->sublist = head;
+               cmdest->subcount = cmsrc->subcount;
+       }
+
+       return 0;
+}
+
+int cmesh_set_name(struct cmesh *cm, const char *name)
+{
+       int len = strlen(name);
+       char *tmp = malloc(len + 1);
+       if(!tmp) return -1;
+       free(cm->name);
+       cm->name = tmp;
+       memcpy(cm->name, name, len + 1);
+       return 0;
+}
+
+const char *cmesh_name(struct cmesh *cm)
+{
+       return cm->name;
+}
+
+int cmesh_has_attrib(struct cmesh *cm, int attr)
+{
+       if(attr < 0 || attr >= CMESH_NUM_ATTR) {
+               return 0;
+       }
+       return cm->vattr[attr].vbo_valid | cm->vattr[attr].data_valid;
+}
+
+int cmesh_indexed(struct cmesh *cm)
+{
+       return cm->ibo_valid | cm->idata_valid;
+}
+
+/* vdata can be 0, in which case only memory is allocated
+ * returns pointer to the attribute array
+ */
+float *cmesh_set_attrib(struct cmesh *cm, int attr, int nelem, unsigned int num,
+               const float *vdata)
+{
+       float *newarr;
+
+       if(attr < 0 || attr >= CMESH_NUM_ATTR) {
+               return 0;
+       }
+       if(cm->nverts && num != cm->nverts) {
+               return 0;
+       }
+
+       if(!(newarr = malloc(num * nelem * sizeof *newarr))) {
+               return 0;
+       }
+       if(vdata) {
+               memcpy(newarr, vdata, num * nelem * sizeof *newarr);
+       }
+
+       cm->nverts = num;
+
+       free(cm->vattr[attr].data);
+       cm->vattr[attr].data = newarr;
+       cm->vattr[attr].count = num * nelem;
+       cm->vattr[attr].nelem = nelem;
+       cm->vattr[attr].data_valid = 1;
+       cm->vattr[attr].vbo_valid = 0;
+       return newarr;
+}
+
+float *cmesh_attrib(struct cmesh *cm, int attr)
+{
+       if(attr < 0 || attr >= CMESH_NUM_ATTR) {
+               return 0;
+       }
+       cm->vattr[attr].vbo_valid = 0;
+       return (float*)cmesh_attrib_ro(cm, attr);
+}
+
+const float *cmesh_attrib_ro(struct cmesh *cm, int attr)
+{
+       void *tmp;
+       int nelem;
+
+       if(attr < 0 || attr >= CMESH_NUM_ATTR) {
+               return 0;
+       }
+
+       if(!cm->vattr[attr].data_valid) {
+#if GL_ES_VERSION_2_0
+               return 0;
+#else
+               if(!cm->vattr[attr].vbo_valid) {
+                       return 0;
+               }
+
+               /* local data copy unavailable, grab the data from the vbo */
+               nelem = cm->vattr[attr].nelem;
+               if(!(cm->vattr[attr].data = malloc(cm->nverts * nelem * sizeof(float)))) {
+                       return 0;
+               }
+               cm->vattr[attr].count = cm->nverts * nelem;
+
+               glBindBuffer(GL_ARRAY_BUFFER, cm->vattr[attr].vbo);
+               tmp = glMapBuffer(GL_ARRAY_BUFFER, GL_READ_ONLY);
+               memcpy(cm->vattr[attr].data, tmp, cm->nverts * nelem * sizeof(float));
+               glUnmapBuffer(GL_ARRAY_BUFFER);
+
+               cm->vattr[attr].data_valid = 1;
+#endif
+       }
+       return cm->vattr[attr].data;
+}
+
+float *cmesh_attrib_at(struct cmesh *cm, int attr, int idx)
+{
+       float *vptr = cmesh_attrib(cm, attr);
+       return vptr ? vptr + idx * cm->vattr[attr].nelem : 0;
+}
+
+const float *cmesh_attrib_at_ro(struct cmesh *cm, int attr, int idx)
+{
+       const float *vptr = cmesh_attrib_ro(cm, attr);
+       return vptr ? vptr + idx * cm->vattr[attr].nelem : 0;
+}
+
+int cmesh_attrib_count(struct cmesh *cm, int attr)
+{
+       return cmesh_has_attrib(cm, attr) ? cm->nverts : 0;
+}
+
+int cmesh_push_attrib(struct cmesh *cm, int attr, float *v)
+{
+       float *vptr;
+       int i, cursz, newsz;
+
+       if(!cm->vattr[attr].nelem) {
+               cm->vattr[attr].nelem = def_nelem[attr];
+       }
+
+       cursz = cm->vattr[attr].count;
+       newsz = cursz + cm->vattr[attr].nelem;
+       if(!(vptr = realloc(cm->vattr[attr].data, newsz * sizeof(float)))) {
+               return -1;
+       }
+       cm->vattr[attr].data = vptr;
+       cm->vattr[attr].count = newsz;
+       vptr += cursz;
+
+       for(i=0; i<cm->vattr[attr].nelem; i++) {
+               *vptr++ = *v++;
+       }
+       cm->vattr[attr].data_valid = 1;
+       cm->vattr[attr].vbo_valid = 0;
+
+       if(attr == CMESH_ATTR_VERTEX) {
+               cm->nverts = newsz / cm->vattr[attr].nelem;
+       }
+       return 0;
+}
+
+int cmesh_push_attrib1f(struct cmesh *cm, int attr, float x)
+{
+       float v[4];
+       v[0] = x;
+       v[1] = v[2] = 0.0f;
+       v[3] = 1.0f;
+       return cmesh_push_attrib(cm, attr, v);
+}
+
+int cmesh_push_attrib2f(struct cmesh *cm, int attr, float x, float y)
+{
+       float v[4];
+       v[0] = x;
+       v[1] = y;
+       v[2] = 0.0f;
+       v[3] = 1.0f;
+       return cmesh_push_attrib(cm, attr, v);
+}
+
+int cmesh_push_attrib3f(struct cmesh *cm, int attr, float x, float y, float z)
+{
+       float v[4];
+       v[0] = x;
+       v[1] = y;
+       v[2] = z;
+       v[3] = 1.0f;
+       return cmesh_push_attrib(cm, attr, v);
+}
+
+int cmesh_push_attrib4f(struct cmesh *cm, int attr, float x, float y, float z, float w)
+{
+       float v[4];
+       v[0] = x;
+       v[1] = y;
+       v[2] = z;
+       v[3] = w;
+       return cmesh_push_attrib(cm, attr, v);
+}
+
+/* indices can be 0, in which case only memory is allocated
+ * returns pointer to the index array
+ */
+unsigned int *cmesh_set_index(struct cmesh *cm, int num, const unsigned int *indices)
+{
+       unsigned int *tmp;
+       int nidx = cm->nfaces * 3;
+
+       if(nidx && num != nidx) {
+               return 0;
+       }
+
+       if(!(tmp = malloc(num * sizeof *tmp))) {
+               return 0;
+       }
+       if(indices) {
+               memcpy(tmp, indices, num * sizeof *tmp);
+       }
+
+       free(cm->idata);
+       cm->idata = tmp;
+       cm->icount = num;
+       cm->idata_valid = 1;
+       cm->ibo_valid = 0;
+       return tmp;
+}
+
+unsigned int *cmesh_index(struct cmesh *cm)
+{
+       cm->ibo_valid = 0;
+       return (unsigned int*)cmesh_index_ro(cm);
+}
+
+const unsigned int *cmesh_index_ro(struct cmesh *cm)
+{
+       int nidx;
+       unsigned int *tmp;
+
+       if(!cm->idata_valid) {
+#if GL_ES_VERSION_2_0
+               return 0;
+#else
+               if(!cm->ibo_valid) {
+                       return 0;
+               }
+
+               /* local copy is unavailable, grab the data from the ibo */
+               nidx = cm->nfaces * 3;
+               if(!(tmp = malloc(nidx * sizeof *cm->idata))) {
+                       return 0;
+               }
+               free(cm->idata);
+               cm->idata = tmp;
+               cm->icount = nidx;
+
+               glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, cm->ibo);
+               tmp = glMapBuffer(GL_ELEMENT_ARRAY_BUFFER, GL_READ_ONLY);
+               memcpy(cm->idata, tmp, nidx * sizeof *cm->idata);
+               glUnmapBuffer(GL_ELEMENT_ARRAY_BUFFER);
+
+               cm->idata_valid = 1;
+#endif
+       }
+       return cm->idata;
+}
+
+int cmesh_index_count(struct cmesh *cm)
+{
+       return cm->nfaces * 3;
+}
+
+int cmesh_push_index(struct cmesh *cm, unsigned int idx)
+{
+       unsigned int *iptr;
+       unsigned int cur_sz = cm->icount;
+       if(!(iptr = realloc(cm->idata, (cur_sz + 1) * sizeof *iptr))) {
+               return -1;
+       }
+       iptr[cur_sz] = idx;
+       cm->idata = iptr;
+       cm->icount = cur_sz + 1;
+       cm->idata_valid = 1;
+       cm->ibo_valid = 0;
+
+       cm->nfaces = cm->icount / 3;
+       return 0;
+}
+
+int cmesh_poly_count(struct cmesh *cm)
+{
+       if(cm->nfaces) {
+               return cm->nfaces;
+       }
+       if(cm->nverts) {
+               return cm->nverts / 3;
+       }
+       return 0;
+}
+
+/* attr can be -1 to invalidate all attributes */
+void cmesh_invalidate_vbo(struct cmesh *cm, int attr)
+{
+       int i;
+
+       if(attr >= CMESH_NUM_ATTR) {
+               return;
+       }
+
+       if(attr < 0) {
+               for(i=0; i<CMESH_NUM_ATTR; i++) {
+                       cm->vattr[i].vbo_valid = 0;
+               }
+       } else {
+               cm->vattr[attr].vbo_valid = 0;
+       }
+}
+
+void cmesh_invalidate_index(struct cmesh *cm)
+{
+       cm->ibo_valid = 0;
+}
+
+int cmesh_append(struct cmesh *cmdest, struct cmesh *cmsrc)
+{
+       int i, nelem, newsz, origsz, srcsz;
+       float *vptr;
+       unsigned int *iptr;
+       unsigned int idxoffs;
+
+       if(!cmdest->nverts) {
+               return cmesh_clone(cmdest, cmsrc);
+       }
+
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               if(cmesh_has_attrib(cmdest, i) && cmesh_has_attrib(cmsrc, i)) {
+                       /* force validation of the data arrays */
+                       cmesh_attrib(cmdest, i);
+                       cmesh_attrib_ro(cmsrc, i);
+
+                       assert(cmdest->vattr[i].nelem == cmsrc->vattr[i].nelem);
+                       nelem = cmdest->vattr[i].nelem;
+                       origsz = cmdest->nverts * nelem;
+                       newsz = cmdest->nverts + cmsrc->nverts * nelem;
+
+                       if(!(vptr = realloc(cmdest->vattr[i].data, newsz * sizeof *vptr))) {
+                               return -1;
+                       }
+                       memcpy(vptr + origsz, cmsrc->vattr[i].data, cmsrc->nverts * nelem * sizeof(float));
+                       cmdest->vattr[i].data = vptr;
+                       cmdest->vattr[i].count = newsz;
+               }
+       }
+
+       if(cmesh_indexed(cmdest)) {
+               assert(cmesh_indexed(cmsrc));
+               /* force validation ... */
+               cmesh_index(cmdest);
+               cmesh_index_ro(cmsrc);
+
+               idxoffs = cmdest->nverts;
+               origsz = cmdest->icount;
+               srcsz = cmsrc->icount;
+               newsz = origsz + srcsz;
+
+               if(!(iptr = realloc(cmdest->idata, newsz * sizeof *iptr))) {
+                       return -1;
+               }
+               cmdest->idata = iptr;
+               cmdest->icount = newsz;
+
+               /* copy and fixup all the new indices */
+               iptr += origsz;
+               for(i=0; i<srcsz; i++) {
+                       *iptr++ = cmsrc->idata[i] + idxoffs;
+               }
+       }
+
+       cmdest->wire_ibo_valid = 0;
+       cmdest->aabb_valid = 0;
+       cmdest->bsph_valid = 0;
+       return 0;
+}
+
+void cmesh_clear_submeshes(struct cmesh *cm)
+{
+       struct submesh *sm;
+
+       while(cm->sublist) {
+               sm = cm->sublist;
+               cm->sublist = cm->sublist->next;
+               free(sm->name);
+               free(sm);
+       }
+       cm->subcount = 0;
+}
+
+int cmesh_submesh(struct cmesh *cm, const char *name, int fstart, int fcount)
+{
+       int i;
+       unsigned int minv = UINT_MAX, maxv = 0;
+       unsigned int *iptr;
+       struct submesh *sm;
+
+       if(fstart < 0 || fcount < 1 || fstart + fcount > cm->nfaces) {
+               return -1;
+       }
+
+       if(!(sm = malloc(sizeof *sm)) || !(sm->name = malloc(strlen(name) + 1))) {
+               free(sm);
+               return -1;
+       }
+       strcpy(sm->name, name);
+       sm->nfaces = fcount;
+
+       if(cmesh_indexed(cm)) {
+               sm->istart = fstart * 3;
+               sm->icount = fcount * 3;
+
+               /* find out which vertices are used by this submesh */
+               iptr = cm->idata + sm->istart;
+               for(i=0; i<sm->icount; i++) {
+                       unsigned int vidx = *iptr++;
+                       if(vidx < minv) minv = vidx;
+                       if(vidx > maxv) maxv = vidx;
+               }
+               sm->vstart = minv;
+               sm->vcount = maxv - minv + 1;
+       } else {
+               sm->istart = sm->icount = 0;
+               sm->vstart = fstart * 3;
+               sm->vcount = fcount * 3;
+       }
+
+       sm->next = cm->sublist;
+       cm->sublist = sm;
+       cm->subcount++;
+       return 0;
+}
+
+int cmesh_remove_submesh(struct cmesh *cm, int idx)
+{
+       struct submesh dummy;
+       struct submesh *prev, *sm;
+
+       if(idx >= cm->subcount) {
+               return -1;
+       }
+
+       dummy.next = cm->sublist;
+       prev = &dummy;
+
+       while(prev->next && idx-- > 0) {
+               prev = prev->next;
+       }
+
+       if(!(sm = prev->next)) return -1;
+
+       prev->next = sm->next;
+       free(sm->name);
+       free(sm);
+
+       cm->subcount--;
+       assert(cm->subcount >= 0);
+
+       cm->sublist = dummy.next;
+       return 0;
+}
+
+int cmesh_find_submesh(struct cmesh *cm, const char *name)
+{
+       int idx = 0;
+       struct submesh *sm = cm->sublist;
+       while(sm) {
+               if(strcmp(sm->name, name) == 0) {
+                       assert(idx <= cm->subcount);
+                       return idx;
+               }
+               idx++;
+               sm = sm->next;
+       }
+       return -1;
+}
+
+int cmesh_submesh_count(struct cmesh *cm)
+{
+       return cm->subcount;
+}
+
+static struct submesh *get_submesh(struct cmesh *m, int idx)
+{
+       struct submesh *sm = m->sublist;
+       while(sm && --idx >= 0) {
+               sm = sm->next;
+       }
+       return sm;
+}
+
+int cmesh_clone_submesh(struct cmesh *cmdest, struct cmesh *cm, int subidx)
+{
+       struct submesh *sub;
+
+       if(!(sub = get_submesh(cm, subidx))) {
+               return -1;
+       }
+       return clone(cmdest, cm, sub);
+}
+
+
+/* assemble a complete vertex by adding all the useful attributes */
+int cmesh_vertex(struct cmesh *cm, float x, float y, float z)
+{
+       int i, j;
+
+       cgm_wcons(cm->cur_val + CMESH_ATTR_VERTEX, x, y, z, 1.0f);
+       cm->vattr[CMESH_ATTR_VERTEX].data_valid = 1;
+       cm->vattr[CMESH_ATTR_VERTEX].nelem = 3;
+
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               if(cm->vattr[i].data_valid) {
+                       int newsz = cm->vattr[i].count + cm->vattr[i].nelem;
+                       float *tmp = realloc(cm->vattr[i].data, newsz * sizeof *tmp);
+                       if(!tmp) return -1;
+                       tmp += cm->vattr[i].count;
+
+                       cm->vattr[i].data = tmp;
+                       cm->vattr[i].count = newsz;
+
+                       for(j=0; j<cm->vattr[i].nelem; j++) {
+                               *tmp++ = *(&cm->cur_val[i].x + j);
+                       }
+               }
+               cm->vattr[i].vbo_valid = 0;
+               cm->vattr[i].data_valid = 1;
+       }
+
+       if(cm->idata_valid) {
+               free(cm->idata);
+               cm->idata = 0;
+               cm->icount = 0;
+       }
+       cm->ibo_valid = cm->idata_valid = 0;
+       return 0;
+}
+
+void cmesh_normal(struct cmesh *cm, float nx, float ny, float nz)
+{
+       cgm_wcons(cm->cur_val + CMESH_ATTR_NORMAL, nx, ny, nz, 1.0f);
+       cm->vattr[CMESH_ATTR_NORMAL].nelem = 3;
+}
+
+void cmesh_tangent(struct cmesh *cm, float tx, float ty, float tz)
+{
+       cgm_wcons(cm->cur_val + CMESH_ATTR_TANGENT, tx, ty, tz, 1.0f);
+       cm->vattr[CMESH_ATTR_TANGENT].nelem = 3;
+}
+
+void cmesh_texcoord(struct cmesh *cm, float u, float v, float w)
+{
+       cgm_wcons(cm->cur_val + CMESH_ATTR_TEXCOORD, u, v, w, 1.0f);
+       cm->vattr[CMESH_ATTR_TEXCOORD].nelem = 3;
+}
+
+void cmesh_boneweights(struct cmesh *cm, float w1, float w2, float w3, float w4)
+{
+       cgm_wcons(cm->cur_val + CMESH_ATTR_BONEWEIGHTS, w1, w2, w3, w4);
+       cm->vattr[CMESH_ATTR_BONEWEIGHTS].nelem = 4;
+}
+
+void cmesh_boneidx(struct cmesh *cm, int idx1, int idx2, int idx3, int idx4)
+{
+       cgm_wcons(cm->cur_val + CMESH_ATTR_BONEIDX, idx1, idx2, idx3, idx4);
+       cm->vattr[CMESH_ATTR_BONEIDX].nelem = 4;
+}
+
+static float *get_vec4(struct cmesh *cm, int attr, int idx, cgm_vec4 *res)
+{
+       int i;
+       float *sptr, *dptr;
+       cgm_wcons(res, 0, 0, 0, 1);
+       if(!(sptr = cmesh_attrib_at(cm, attr, idx))) {
+               return 0;
+       }
+       dptr = &res->x;
+
+       for(i=0; i<cm->vattr[attr].nelem; i++) {
+               *dptr++ = sptr[i];
+       }
+       return sptr;
+}
+
+static float *get_vec3(struct cmesh *cm, int attr, int idx, cgm_vec3 *res)
+{
+       int i;
+       float *sptr, *dptr;
+       cgm_vcons(res, 0, 0, 0);
+       if(!(sptr = cmesh_attrib_at(cm, attr, idx))) {
+               return 0;
+       }
+       dptr = &res->x;
+
+       for(i=0; i<cm->vattr[attr].nelem; i++) {
+               *dptr++ = sptr[i];
+       }
+       return sptr;
+}
+
+/* dir_xform can be null, in which case it's calculated from xform */
+void cmesh_apply_xform(struct cmesh *cm, float *xform, float *dir_xform)
+{
+       unsigned int i;
+       int j;
+       cgm_vec4 v;
+       cgm_vec3 n, t;
+       float *vptr;
+
+       for(i=0; i<cm->nverts; i++) {
+               if(!(vptr = get_vec4(cm, CMESH_ATTR_VERTEX, i, &v))) {
+                       return;
+               }
+               cgm_wmul_m4v4(&v, xform);
+               for(j=0; j<cm->vattr[CMESH_ATTR_VERTEX].nelem; j++) {
+                       *vptr++ = (&v.x)[j];
+               }
+
+               if(cmesh_has_attrib(cm, CMESH_ATTR_NORMAL)) {
+                       if((vptr = get_vec3(cm, CMESH_ATTR_NORMAL, i, &n))) {
+                               cgm_vmul_m3v3(&n, dir_xform);
+                               for(j=0; j<cm->vattr[CMESH_ATTR_NORMAL].nelem; j++) {
+                                       *vptr++ = (&n.x)[j];
+                               }
+                       }
+               }
+               if(cmesh_has_attrib(cm, CMESH_ATTR_TANGENT)) {
+                       if((vptr = get_vec3(cm, CMESH_ATTR_TANGENT, i, &t))) {
+                               cgm_vmul_m3v3(&t, dir_xform);
+                               for(j=0; j<cm->vattr[CMESH_ATTR_TANGENT].nelem; j++) {
+                                       *vptr++ = (&t.x)[j];
+                               }
+                       }
+               }
+       }
+}
+
+void cmesh_flip(struct cmesh *cm)
+{
+       cmesh_flip_faces(cm);
+       cmesh_flip_normals(cm);
+}
+
+void cmesh_flip_faces(struct cmesh *cm)
+{
+       int i, j, idxnum, vnum, nelem;
+       unsigned int *indices;
+       float *verts, *vptr;
+
+       if(cmesh_indexed(cm)) {
+               if(!(indices = cmesh_index(cm))) {
+                       return;
+               }
+               idxnum = cmesh_index_count(cm);
+               for(i=0; i<idxnum; i+=3) {
+                       unsigned int tmp = indices[i + 2];
+                       indices[i + 2] = indices[i + 1];
+                       indices[i + 1] = tmp;
+               }
+       } else {
+               if(!(verts = cmesh_attrib(cm, CMESH_ATTR_VERTEX))) {
+                       return;
+               }
+               vnum = cmesh_attrib_count(cm, CMESH_ATTR_VERTEX);
+               nelem = cm->vattr[CMESH_ATTR_VERTEX].nelem;
+               for(i=0; i<vnum; i+=3) {
+                       for(j=0; j<nelem; j++) {
+                               vptr = verts + (i + 1) * nelem + j;
+                               float tmp = vptr[nelem];
+                               vptr[nelem] = vptr[0];
+                               vptr[0] = tmp;
+                       }
+               }
+       }
+}
+void cmesh_flip_normals(struct cmesh *cm)
+{
+       int i, num;
+       float *nptr = cmesh_attrib(cm, CMESH_ATTR_NORMAL);
+       if(!nptr) return;
+
+       num = cm->nverts * cm->vattr[CMESH_ATTR_NORMAL].nelem;
+       for(i=0; i<num; i++) {
+               *nptr = -*nptr;
+               nptr++;
+       }
+}
+
+int cmesh_explode(struct cmesh *cm)
+{
+       int i, j, k, idxnum, nnverts;
+       unsigned int *indices;
+
+       if(!cmesh_indexed(cm)) return 0;
+
+       indices = cmesh_index(cm);
+       assert(indices);
+
+       idxnum = cmesh_index_count(cm);
+       nnverts = idxnum;
+
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               const float *srcbuf;
+               float *tmpbuf, *dstptr;
+
+               if(!cmesh_has_attrib(cm, i)) continue;
+
+               srcbuf = cmesh_attrib(cm, i);
+               if(!(tmpbuf = malloc(nnverts * cm->vattr[i].nelem * sizeof(float)))) {
+                       return -1;
+               }
+               dstptr = tmpbuf;
+
+               for(j=0; j<idxnum; j++) {
+                       unsigned int idx = indices[j];
+                       const float *srcptr = srcbuf + idx * cm->vattr[i].nelem;
+
+                       for(k=0; k<cm->vattr[i].nelem; k++) {
+                               *dstptr++ = *srcptr++;
+                       }
+               }
+
+               free(cm->vattr[i].data);
+               cm->vattr[i].data = tmpbuf;
+               cm->vattr[i].count = nnverts * cm->vattr[i].nelem;
+               cm->vattr[i].data_valid = 1;
+       }
+
+       cm->ibo_valid = 0;
+       cm->idata_valid = 0;
+       free(cm->idata);
+       cm->idata = 0;
+       cm->icount = 0;
+
+       cm->nverts = nnverts;
+       cm->nfaces = idxnum / 3;
+       return 0;
+}
+
+void cmesh_calc_face_normals(struct cmesh *cm)
+{
+       /* TODO */
+}
+
+static int pre_draw(struct cmesh *cm)
+{
+       int i, loc, cur_sdr;
+
+       glGetIntegerv(GL_CURRENT_PROGRAM, &cur_sdr);
+
+       update_buffers(cm);
+
+       if(!cm->vattr[CMESH_ATTR_VERTEX].vbo_valid) {
+               return -1;
+       }
+
+       if(cur_sdr && use_custom_sdr_attr) {
+               if(sdr_loc[CMESH_ATTR_VERTEX] == -1) {
+                       return -1;
+               }
+
+               for(i=0; i<CMESH_NUM_ATTR; i++) {
+                       loc = sdr_loc[i];
+                       if(loc >= 0 && cm->vattr[i].vbo_valid) {
+                               glBindBuffer(GL_ARRAY_BUFFER, cm->vattr[i].vbo);
+                               glVertexAttribPointer(loc, cm->vattr[i].nelem, GL_FLOAT, GL_FALSE, 0, 0);
+                               glEnableVertexAttribArray(loc);
+                       }
+               }
+       } else {
+#ifndef GL_ES_VERSION_2_0
+               glBindBuffer(GL_ARRAY_BUFFER, cm->vattr[CMESH_ATTR_VERTEX].vbo);
+               glVertexPointer(cm->vattr[CMESH_ATTR_VERTEX].nelem, GL_FLOAT, 0, 0);
+               glEnableClientState(GL_VERTEX_ARRAY);
+
+               if(cm->vattr[CMESH_ATTR_NORMAL].vbo_valid) {
+                       glBindBuffer(GL_ARRAY_BUFFER, cm->vattr[CMESH_ATTR_NORMAL].vbo);
+                       glNormalPointer(GL_FLOAT, 0, 0);
+                       glEnableClientState(GL_NORMAL_ARRAY);
+               }
+               if(cm->vattr[CMESH_ATTR_TEXCOORD].vbo_valid) {
+                       glBindBuffer(GL_ARRAY_BUFFER, cm->vattr[CMESH_ATTR_TEXCOORD].vbo);
+                       glTexCoordPointer(cm->vattr[CMESH_ATTR_TEXCOORD].nelem, GL_FLOAT, 0, 0);
+                       glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+               }
+               if(cm->vattr[CMESH_ATTR_COLOR].vbo_valid) {
+                       glBindBuffer(GL_ARRAY_BUFFER, cm->vattr[CMESH_ATTR_COLOR].vbo);
+                       glColorPointer(cm->vattr[CMESH_ATTR_COLOR].nelem, GL_FLOAT, 0, 0);
+                       glEnableClientState(GL_COLOR_ARRAY);
+               }
+               if(cm->vattr[CMESH_ATTR_TEXCOORD2].vbo_valid) {
+                       glClientActiveTexture(GL_TEXTURE1);
+                       glBindBuffer(GL_ARRAY_BUFFER, cm->vattr[CMESH_ATTR_TEXCOORD2].vbo);
+                       glTexCoordPointer(cm->vattr[CMESH_ATTR_TEXCOORD2].nelem, GL_FLOAT, 0, 0);
+                       glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+                       glClientActiveTexture(GL_TEXTURE0);
+               }
+#endif /* GL_ES_VERSION_2_0 */
+       }
+       glBindBuffer(GL_ARRAY_BUFFER, 0);
+       return cur_sdr;
+}
+
+void cmesh_draw(struct cmesh *cm)
+{
+       if(cm->ibo_valid) {
+               cmesh_draw_range(cm, 0, cm->nfaces * 3);
+       } else {
+               cmesh_draw_range(cm, 0, cm->nverts);
+       }
+}
+
+void cmesh_draw_range(struct cmesh *cm, int start, int count)
+{
+       int cur_sdr;
+
+       if((cur_sdr = pre_draw(cm)) == -1) {
+               return;
+       }
+
+       if(cm->ibo_valid) {
+               glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, cm->ibo);
+               glDrawElements(GL_TRIANGLES, count, GL_UNSIGNED_INT, (void*)(start * 4));
+               glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+       } else {
+               glDrawArrays(GL_TRIANGLES, start, count);
+       }
+
+       post_draw(cm, cur_sdr);
+}
+
+void cmesh_draw_submesh(struct cmesh *cm, int subidx)
+{
+       struct submesh *sm = cm->sublist;
+
+       while(sm && subidx-- > 0) {
+               sm = sm->next;
+       }
+       if(!sm) return;
+
+       if(sm->icount) {
+               cmesh_draw_range(cm, sm->istart, sm->icount);
+       } else {
+               cmesh_draw_range(cm, sm->vstart, sm->vcount);
+       }
+}
+
+static void post_draw(struct cmesh *cm, int cur_sdr)
+{
+       int i;
+
+       if(cur_sdr && use_custom_sdr_attr) {
+               for(i=0; i<CMESH_NUM_ATTR; i++) {
+                       int loc = sdr_loc[i];
+                       if(loc >= 0 && cm->vattr[i].vbo_valid) {
+                               glDisableVertexAttribArray(loc);
+                       }
+               }
+       } else {
+#ifndef GL_ES_VERSION_2_0
+               glDisableClientState(GL_VERTEX_ARRAY);
+               if(cm->vattr[CMESH_ATTR_NORMAL].vbo_valid) {
+                       glDisableClientState(GL_NORMAL_ARRAY);
+               }
+               if(cm->vattr[CMESH_ATTR_TEXCOORD].vbo_valid) {
+                       glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+               }
+               if(cm->vattr[CMESH_ATTR_COLOR].vbo_valid) {
+                       glDisableClientState(GL_COLOR_ARRAY);
+               }
+               if(cm->vattr[CMESH_ATTR_TEXCOORD2].vbo_valid) {
+                       glClientActiveTexture(GL_TEXTURE1);
+                       glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+                       glClientActiveTexture(GL_TEXTURE0);
+               }
+#endif /* GL_ES_VERSION_2_0 */
+       }
+}
+
+void cmesh_draw_wire(struct cmesh *cm, float linesz)
+{
+       int cur_sdr, nfaces;
+
+       if((cur_sdr = pre_draw(cm)) == -1) {
+               return;
+       }
+       update_wire_ibo(cm);
+
+       nfaces = cmesh_poly_count(cm);
+       glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, cm->wire_ibo);
+       glDrawElements(GL_LINES, nfaces * 6, GL_UNSIGNED_INT, 0);
+       glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+       post_draw(cm, cur_sdr);
+}
+
+void cmesh_draw_vertices(struct cmesh *cm, float ptsz)
+{
+       int cur_sdr;
+       if((cur_sdr = pre_draw(cm)) == -1) {
+               return;
+       }
+
+       glPushAttrib(GL_POINT_BIT);
+       glPointSize(ptsz);
+       glDrawArrays(GL_POINTS, 0, cm->nverts);
+       glPopAttrib();
+
+       post_draw(cm, cur_sdr);
+}
+
+void cmesh_draw_normals(struct cmesh *cm, float len)
+{
+#ifndef GL_ES_VERSION_2_0
+       int i, cur_sdr, vert_nelem, norm_nelem;
+       int loc = -1;
+       const float *varr, *norm;
+
+       varr = cmesh_attrib_ro(cm, CMESH_ATTR_VERTEX);
+       norm = cmesh_attrib_ro(cm, CMESH_ATTR_NORMAL);
+       if(!varr || !norm) return;
+
+       vert_nelem = cm->vattr[CMESH_ATTR_VERTEX].nelem;
+       norm_nelem = cm->vattr[CMESH_ATTR_NORMAL].nelem;
+
+       glGetIntegerv(GL_CURRENT_PROGRAM, &cur_sdr);
+       if(cur_sdr && use_custom_sdr_attr) {
+               if((loc = sdr_loc[CMESH_ATTR_VERTEX]) < 0) {
+                       return;
+               }
+       }
+
+       glBegin(GL_LINES);
+       for(i=0; i<cm->nverts; i++) {
+               float x, y, z, endx, endy, endz;
+
+               x = varr[i * vert_nelem];
+               y = varr[i * vert_nelem + 1];
+               z = varr[i * vert_nelem + 2];
+               endx = x + norm[i * norm_nelem] * len;
+               endy = y + norm[i * norm_nelem + 1] * len;
+               endz = z + norm[i * norm_nelem + 2] * len;
+
+               if(loc == -1) {
+                       glVertex3f(x, y, z);
+                       glVertex3f(endx, endy, endz);
+               } else {
+                       glVertexAttrib3f(loc, x, y, z);
+                       glVertexAttrib3f(loc, endx, endy, endz);
+               }
+       }
+       glEnd();
+#endif /* GL_ES_VERSION_2_0 */
+}
+
+void cmesh_draw_tangents(struct cmesh *cm, float len)
+{
+#ifndef GL_ES_VERSION_2_0
+       int i, cur_sdr, vert_nelem, tang_nelem;
+       int loc = -1;
+       const float *varr, *tang;
+
+       varr = cmesh_attrib_ro(cm, CMESH_ATTR_VERTEX);
+       tang = cmesh_attrib_ro(cm, CMESH_ATTR_TANGENT);
+       if(!varr || !tang) return;
+
+       vert_nelem = cm->vattr[CMESH_ATTR_VERTEX].nelem;
+       tang_nelem = cm->vattr[CMESH_ATTR_TANGENT].nelem;
+
+       glGetIntegerv(GL_CURRENT_PROGRAM, &cur_sdr);
+       if(cur_sdr && use_custom_sdr_attr) {
+               if((loc = sdr_loc[CMESH_ATTR_VERTEX]) < 0) {
+                       return;
+               }
+       }
+
+       glBegin(GL_LINES);
+       for(i=0; i<cm->nverts; i++) {
+               float x, y, z, endx, endy, endz;
+
+               x = varr[i * vert_nelem];
+               y = varr[i * vert_nelem + 1];
+               z = varr[i * vert_nelem + 2];
+               endx = x + tang[i * tang_nelem] * len;
+               endy = y + tang[i * tang_nelem + 1] * len;
+               endz = z + tang[i * tang_nelem + 2] * len;
+
+               if(loc == -1) {
+                       glVertex3f(x, y, z);
+                       glVertex3f(endx, endy, endz);
+               } else {
+                       glVertexAttrib3f(loc, x, y, z);
+                       glVertexAttrib3f(loc, endx, endy, endz);
+               }
+       }
+       glEnd();
+#endif /* GL_ES_VERSION_2_0 */
+}
+
+static void update_buffers(struct cmesh *cm)
+{
+       int i;
+
+       for(i=0; i<CMESH_NUM_ATTR; i++) {
+               if(cmesh_has_attrib(cm, i) && !cm->vattr[i].vbo_valid) {
+                       glBindBuffer(GL_ARRAY_BUFFER, cm->vattr[i].vbo);
+                       glBufferData(GL_ARRAY_BUFFER, cm->nverts * cm->vattr[i].nelem * sizeof(float),
+                                       cm->vattr[i].data, GL_STATIC_DRAW);
+                       cm->vattr[i].vbo_valid = 1;
+               }
+       }
+       glBindBuffer(GL_ARRAY_BUFFER, 0);
+
+       if(cm->idata_valid && !cm->ibo_valid) {
+               glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, cm->ibo);
+               glBufferData(GL_ELEMENT_ARRAY_BUFFER, cm->nfaces * 3 * sizeof(unsigned int),
+                               cm->idata, GL_STATIC_DRAW);
+               cm->ibo_valid = 1;
+               glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+       }
+}
+
+static void update_wire_ibo(struct cmesh *cm)
+{
+       int i, num_faces;
+       unsigned int *wire_idxarr, *dest;
+
+       update_buffers(cm);
+
+       if(cm->wire_ibo_valid) return;
+
+       if(!cm->wire_ibo) {
+               glGenBuffers(1, &cm->wire_ibo);
+       }
+       num_faces = cmesh_poly_count(cm);
+
+       if(!(wire_idxarr = malloc(num_faces * 6 * sizeof *wire_idxarr))) {
+               return;
+       }
+       dest = wire_idxarr;
+
+       if(cm->ibo_valid) {
+               /* we're dealing with an indexed mesh */
+               const unsigned int *idxarr = cmesh_index_ro(cm);
+
+               for(i=0; i<num_faces; i++) {
+                       *dest++ = idxarr[0];
+                       *dest++ = idxarr[1];
+                       *dest++ = idxarr[1];
+                       *dest++ = idxarr[2];
+                       *dest++ = idxarr[2];
+                       *dest++ = idxarr[0];
+                       idxarr += 3;
+               }
+       } else {
+               /* not an indexed mesh */
+               for(i=0; i<num_faces; i++) {
+                       int vidx = i * 3;
+                       *dest++ = vidx;
+                       *dest++ = vidx + 1;
+                       *dest++ = vidx + 1;
+                       *dest++ = vidx + 2;
+                       *dest++ = vidx + 2;
+                       *dest++ = vidx;
+               }
+       }
+
+       glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, cm->wire_ibo);
+       glBufferData(GL_ELEMENT_ARRAY_BUFFER, num_faces * 6 * sizeof(unsigned int),
+                       wire_idxarr, GL_STATIC_DRAW);
+       free(wire_idxarr);
+       cm->wire_ibo_valid = 1;
+       glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+}
+
+static void calc_aabb(struct cmesh *cm)
+{
+       int i, j;
+
+       if(!cmesh_attrib_ro(cm, CMESH_ATTR_VERTEX)) {
+               return;
+       }
+
+       cgm_vcons(&cm->aabb_min, FLT_MAX, FLT_MAX, FLT_MAX);
+       cgm_vcons(&cm->aabb_max, -FLT_MAX, -FLT_MAX, -FLT_MAX);
+
+       for(i=0; i<cm->nverts; i++) {
+               const float *v = cmesh_attrib_at_ro(cm, CMESH_ATTR_VERTEX, i);
+               for(j=0; j<3; j++) {
+                       if(v[j] < (&cm->aabb_min.x)[j]) {
+                               (&cm->aabb_min.x)[j] = v[j];
+                       }
+                       if(v[j] > (&cm->aabb_max.x)[j]) {
+                               (&cm->aabb_max.x)[j] = v[j];
+                       }
+               }
+       }
+       cm->aabb_valid = 1;
+}
+
+void cmesh_aabbox(struct cmesh *cm, cgm_vec3 *vmin, cgm_vec3 *vmax)
+{
+       if(!cm->aabb_valid) {
+               calc_aabb(cm);
+       }
+       *vmin = cm->aabb_min;
+       *vmax = cm->aabb_max;
+}
+
+static void calc_bsph(struct cmesh *cm)
+{
+       int i;
+       float s, dist_sq;
+
+       if(!cmesh_attrib_ro(cm, CMESH_ATTR_VERTEX)) {
+               return;
+       }
+
+       cgm_vcons(&cm->bsph_center, 0, 0, 0);
+
+       /* first find the center */
+       for(i=0; i<cm->nverts; i++) {
+               const float *v = cmesh_attrib_at_ro(cm, CMESH_ATTR_VERTEX, i);
+               cm->bsph_center.x += v[0];
+               cm->bsph_center.y += v[1];
+               cm->bsph_center.z += v[2];
+       }
+       s = 1.0f / (float)cm->nverts;
+       cm->bsph_center.x *= s;
+       cm->bsph_center.y *= s;
+       cm->bsph_center.z *= s;
+
+       cm->bsph_radius = 0.0f;
+       for(i=0; i<cm->nverts; i++) {
+               const cgm_vec3 *v = (const cgm_vec3*)cmesh_attrib_at_ro(cm, CMESH_ATTR_VERTEX, i);
+               if((dist_sq = cgm_vdist_sq(v, &cm->bsph_center)) > cm->bsph_radius) {
+                       cm->bsph_radius = dist_sq;
+               }
+       }
+       cm->bsph_radius = sqrt(cm->bsph_radius);
+       cm->bsph_valid = 1;
+}
+
+float cmesh_bsphere(struct cmesh *cm, cgm_vec3 *center, float *rad)
+{
+       if(!cm->bsph_valid) {
+               calc_bsph(cm);
+       }
+       *center = cm->bsph_center;
+       *rad = cm->bsph_radius;
+       return cm->bsph_radius;
+}
+
+/* TODO */
+void cmesh_texcoord_apply_xform(struct cmesh *cm, float *xform);
+void cmesh_texcoord_gen_plane(struct cmesh *cm, cgm_vec3 *norm, cgm_vec3 *tang);
+void cmesh_texcoord_gen_box(struct cmesh *cm);
+void cmesh_texcoord_gen_cylinder(struct cmesh *cm);
+
+int cmesh_dump(struct cmesh *cm, const char *fname)
+{
+       FILE *fp = fopen(fname, "wb");
+       if(fp) {
+               int res = cmesh_dump_file(cm, fp);
+               fclose(fp);
+               return res;
+       }
+       return -1;
+}
+
+int cmesh_dump_file(struct cmesh *cm, FILE *fp)
+{
+       static const char *label[] = { "pos", "nor", "tan", "tex", "col", "bw", "bid", "tex2" };
+       static const char *elemfmt[] = { 0, " %s(%g)", " %s(%g, %g)", " %s(%g, %g, %g)", " %s(%g, %g, %g, %g)", 0 };
+       int i, j;
+
+       if(!cmesh_has_attrib(cm, CMESH_ATTR_VERTEX)) {
+               return -1;
+       }
+
+       fprintf(fp, "VERTEX ATTRIBUTES\n");
+
+       for(i=0; i<cm->nverts; i++) {
+               fprintf(fp, "%5u:", i);
+               for(j=0; j<CMESH_NUM_ATTR; j++) {
+                       if(cmesh_has_attrib(cm, j)) {
+                               const float *v = cmesh_attrib_at_ro(cm, j, i);
+                               int nelem = cm->vattr[j].nelem;
+                               fprintf(fp, elemfmt[nelem], label[j], v[0], nelem > 1 ? v[1] : 0.0f,
+                                               nelem > 2 ? v[2] : 0.0f, nelem > 3 ? v[3] : 0.0f);
+                       }
+               }
+               fputc('\n', fp);
+       }
+
+       if(cmesh_indexed(cm)) {
+               const unsigned int *idx = cmesh_index_ro(cm);
+               int numidx = cmesh_index_count(cm);
+               int numtri = numidx / 3;
+               assert(numidx % 3 == 0);
+
+               fprintf(fp, "FACES\n");
+
+               for(i=0; i<numtri; i++) {
+                       fprintf(fp, "%5d: %d %d %d\n", i, idx[0], idx[1], idx[2]);
+                       idx += 3;
+               }
+       }
+       return 0;
+}
+
+int cmesh_dump_obj(struct cmesh *cm, const char *fname)
+{
+       FILE *fp = fopen(fname, "wb");
+       if(fp) {
+               int res = cmesh_dump_obj_file(cm, fp, 0);
+               fclose(fp);
+               return res;
+       }
+       return -1;
+}
+
+#define HAS_VN 1
+#define HAS_VT 2
+
+int cmesh_dump_obj_file(struct cmesh *cm, FILE *fp, int voffs)
+{
+       static const char *fmtstr[] = {" %u", " %u//%u", " %u/%u", " %u/%u/%u"};
+       int i, j, num, nelem;
+       unsigned int aflags = 0;
+
+       if(!cmesh_has_attrib(cm, CMESH_ATTR_VERTEX)) {
+               return -1;
+       }
+
+
+       nelem = cm->vattr[CMESH_ATTR_VERTEX].nelem;
+       if((num = cm->vattr[CMESH_ATTR_VERTEX].count) != cm->nverts * nelem) {
+               fprintf(stderr, "vertex array size (%d) != nverts (%d)\n", num, cm->nverts);
+       }
+       for(i=0; i<cm->nverts; i++) {
+               const float *v = cmesh_attrib_at_ro(cm, CMESH_ATTR_VERTEX, i);
+               fprintf(fp, "v %f %f %f\n", v[0], nelem > 1 ? v[1] : 0.0f, nelem > 2 ? v[2] : 0.0f);
+       }
+
+       if(cmesh_has_attrib(cm, CMESH_ATTR_NORMAL)) {
+               aflags |= HAS_VN;
+               nelem = cm->vattr[CMESH_ATTR_NORMAL].nelem;
+               if((num = cm->vattr[CMESH_ATTR_NORMAL].count) != cm->nverts * nelem) {
+                       fprintf(stderr, "normal array size (%d) != nverts (%d)\n", num, cm->nverts);
+               }
+               for(i=0; i<cm->nverts; i++) {
+                       const float *v = cmesh_attrib_at_ro(cm, CMESH_ATTR_NORMAL, i);
+                       fprintf(fp, "vn %f %f %f\n", v[0], nelem > 1 ? v[1] : 0.0f, nelem > 2 ? v[2] : 0.0f);
+               }
+       }
+
+       if(cmesh_has_attrib(cm, CMESH_ATTR_TEXCOORD)) {
+               aflags |= HAS_VT;
+               nelem = cm->vattr[CMESH_ATTR_TEXCOORD].nelem;
+               if((num = cm->vattr[CMESH_ATTR_TEXCOORD].count) != cm->nverts * nelem) {
+                       fprintf(stderr, "texcoord array size (%d) != nverts (%d)\n", num, cm->nverts);
+               }
+               for(i=0; i<cm->nverts; i++) {
+                       const float *v = cmesh_attrib_at_ro(cm, CMESH_ATTR_TEXCOORD, i);
+                       fprintf(fp, "vt %f %f\n", v[0], nelem > 1 ? v[1] : 0.0f);
+               }
+       }
+
+       if(cmesh_indexed(cm)) {
+               const unsigned int *idxptr = cmesh_index_ro(cm);
+               int numidx = cmesh_index_count(cm);
+               int numtri = numidx / 3;
+               assert(numidx % 3 == 0);
+
+               for(i=0; i<numtri; i++) {
+                       fputc('f', fp);
+                       for(j=0; j<3; j++) {
+                               unsigned int idx = *idxptr++ + 1 + voffs;
+                               fprintf(fp, fmtstr[aflags], idx, idx, idx);
+                       }
+                       fputc('\n', fp);
+               }
+       } else {
+               int numtri = cm->nverts / 3;
+               unsigned int idx = 1 + voffs;
+               for(i=0; i<numtri; i++) {
+                       fputc('f', fp);
+                       for(j=0; j<3; j++) {
+                               fprintf(fp, fmtstr[aflags], idx, idx, idx);
+                               ++idx;
+                       }
+                       fputc('\n', fp);
+               }
+       }
+       return 0;
+}
diff --git a/tools/ropesim/src/cmesh.h b/tools/ropesim/src/cmesh.h
new file mode 100644 (file)
index 0000000..920e39d
--- /dev/null
@@ -0,0 +1,138 @@
+#ifndef CMESH_H_
+#define CMESH_H_
+
+#include <stdio.h>
+#include "cgmath/cgmath.h"
+
+enum {
+       CMESH_ATTR_VERTEX,
+       CMESH_ATTR_NORMAL,
+       CMESH_ATTR_TANGENT,
+       CMESH_ATTR_TEXCOORD,
+       CMESH_ATTR_COLOR,
+       CMESH_ATTR_BONEWEIGHTS,
+       CMESH_ATTR_BONEIDX,
+       CMESH_ATTR_TEXCOORD2,
+
+       CMESH_NUM_ATTR
+};
+
+struct cmesh;
+
+/* global state */
+void cmesh_set_attrib_sdrloc(int attr, int loc);
+int cmesh_get_attrib_sdrloc(int attr);
+void cmesh_clear_attrib_sdrloc(void);
+
+/* mesh functions */
+struct cmesh *cmesh_alloc(void);
+void cmesh_free(struct cmesh *cm);
+
+int cmesh_init(struct cmesh *cm);
+void cmesh_destroy(struct cmesh *cm);
+
+void cmesh_clear(struct cmesh *cm);
+int cmesh_clone(struct cmesh *cmdest, struct cmesh *cmsrc);
+
+int cmesh_set_name(struct cmesh *cm, const char *name);
+const char *cmesh_name(struct cmesh *cm);
+
+int cmesh_has_attrib(struct cmesh *cm, int attr);
+int cmesh_indexed(struct cmesh *cm);
+
+/* vdata can be 0, in which case only memory is allocated
+ * returns pointer to the attribute array
+ */
+float *cmesh_set_attrib(struct cmesh *cm, int attr, int nelem, unsigned int num,
+               const float *vdata);
+float *cmesh_attrib(struct cmesh *cm, int attr);                       /* invalidates VBO */
+const float *cmesh_attrib_ro(struct cmesh *cm, int attr);      /* doesn't invalidate */
+float *cmesh_attrib_at(struct cmesh *cm, int attr, int idx);
+const float *cmesh_attrib_at_ro(struct cmesh *cm, int attr, int idx);
+int cmesh_attrib_count(struct cmesh *cm, int attr);
+int cmesh_push_attrib(struct cmesh *cm, int attr, float *v);
+int cmesh_push_attrib1f(struct cmesh *cm, int attr, float x);
+int cmesh_push_attrib2f(struct cmesh *cm, int attr, float x, float y);
+int cmesh_push_attrib3f(struct cmesh *cm, int attr, float x, float y, float z);
+int cmesh_push_attrib4f(struct cmesh *cm, int attr, float x, float y, float z, float w);
+
+/* indices can be 0, in which case only memory is allocated
+ * returns pointer to the index array
+ */
+unsigned int *cmesh_set_index(struct cmesh *cm, int num, const unsigned int *indices);
+unsigned int *cmesh_index(struct cmesh *cm);   /* invalidates IBO */
+const unsigned int *cmesh_index_ro(struct cmesh *cm);  /* doesn't invalidate */
+int cmesh_index_count(struct cmesh *cm);
+int cmesh_push_index(struct cmesh *cm, unsigned int idx);
+
+int cmesh_poly_count(struct cmesh *cm);
+
+/* attr can be -1 to invalidate all attributes */
+void cmesh_invalidate_vbo(struct cmesh *cm, int attr);
+void cmesh_invalidate_ibo(struct cmesh *cm);
+
+int cmesh_append(struct cmesh *cmdest, struct cmesh *cmsrc);
+
+/* submeshes */
+void cmesh_clear_submeshes(struct cmesh *cm);
+/* a submesh is defined as a consecutive range of faces */
+int cmesh_submesh(struct cmesh *cm, const char *name, int fstart, int fcount);
+int cmesh_remove_submesh(struct cmesh *cm, int idx);
+int cmesh_find_submesh(struct cmesh *cm, const char *name);
+int cmesh_submesh_count(struct cmesh *cm);
+int cmesh_clone_submesh(struct cmesh *cmdest, struct cmesh *cm, int subidx);
+
+/* immediate-mode style mesh construction interface */
+int cmesh_vertex(struct cmesh *cm, float x, float y, float z);
+void cmesh_normal(struct cmesh *cm, float nx, float ny, float nz);
+void cmesh_tangent(struct cmesh *cm, float tx, float ty, float tz);
+void cmesh_texcoord(struct cmesh *cm, float u, float v, float w);
+void cmesh_boneweights(struct cmesh *cm, float w1, float w2, float w3, float w4);
+void cmesh_boneidx(struct cmesh *cm, int idx1, int idx2, int idx3, int idx4);
+
+/* dir_xform can be null, in which case it's calculated from xform */
+void cmesh_apply_xform(struct cmesh *cm, float *xform, float *dir_xform);
+
+void cmesh_flip(struct cmesh *cm);     /* flip faces (winding) and normals */
+void cmesh_flip_faces(struct cmesh *cm);
+void cmesh_flip_normals(struct cmesh *cm);
+
+int cmesh_explode(struct cmesh *cm);   /* undo all vertex sharing */
+
+/* this is only guaranteed to work on an exploded mesh */
+void cmesh_calc_face_normals(struct cmesh *cm);
+
+void cmesh_draw(struct cmesh *cm);
+void cmesh_draw_range(struct cmesh *cm, int start, int count);
+void cmesh_draw_submesh(struct cmesh *cm, int subidx); /* XXX only for indexed meshes currently */
+void cmesh_draw_wire(struct cmesh *cm, float linesz);
+void cmesh_draw_vertices(struct cmesh *cm, float ptsz);
+void cmesh_draw_normals(struct cmesh *cm, float len);
+void cmesh_draw_tangents(struct cmesh *cm, float len);
+
+/* get the bounding box in local space. The result will be cached and subsequent
+ * calls will return the same box. The cache gets invalidated by any functions that
+ * can affect the vertex data
+ */
+void cmesh_aabbox(struct cmesh *cm, cgm_vec3 *vmin, cgm_vec3 *vmax);
+
+/* get the bounding sphere in local space. The result will be cached ... see above */
+float cmesh_bsphere(struct cmesh *cm, cgm_vec3 *center, float *rad);
+
+/* texture coordinate manipulation */
+void cmesh_texcoord_apply_xform(struct cmesh *cm, float *xform);
+void cmesh_texcoord_gen_plane(struct cmesh *cm, cgm_vec3 *norm, cgm_vec3 *tang);
+void cmesh_texcoord_gen_box(struct cmesh *cm);
+void cmesh_texcoord_gen_cylinder(struct cmesh *cm);
+
+/* FILE I/O */
+int cmesh_load(struct cmesh *cm, const char *fname);
+
+int cmesh_dump(struct cmesh *cm, const char *fname);
+int cmesh_dump_file(struct cmesh *cm, FILE *fp);
+int cmesh_dump_obj(struct cmesh *cm, const char *fname);
+int cmesh_dump_obj_file(struct cmesh *cm, FILE *fp, int voffs);
+
+
+
+#endif /* CMESH_H_ */
diff --git a/tools/ropesim/src/main.c b/tools/ropesim/src/main.c
new file mode 100644 (file)
index 0000000..dcabef5
--- /dev/null
@@ -0,0 +1,167 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <GL/glut.h>
+#include "cmesh.h"
+
+int init(void);
+void cleanup(void);
+void display(void);
+void idle(void);
+void reshape(int x, int y);
+void keyb(unsigned char key, int x, int y);
+void mouse(int bn, int st, int x, int y);
+void motion(int x, int y);
+void sball_motion(int x, int y, int z);
+void sball_rotate(int rx, int ry, int rz);
+void sball_button(int bn, int st);
+
+float cam_theta, cam_phi, cam_dist = 10;
+int prev_mx, prev_my;
+int bnstate[8];
+
+struct cmesh *scn;
+
+int main(int argc, char **argv)
+{
+       glutInit(&argc, argv);
+       glutInitWindowSize(800, 600);
+       glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+       glutCreateWindow("ropesim");
+
+       glutDisplayFunc(display);
+       glutIdleFunc(idle);
+       glutReshapeFunc(reshape);
+       glutKeyboardFunc(keyb);
+       glutMouseFunc(mouse);
+       glutMotionFunc(motion);
+       glutSpaceballMotionFunc(sball_motion);
+       glutSpaceballRotateFunc(sball_rotate);
+       glutSpaceballButtonFunc(sball_button);
+
+       if(init() == -1) {
+               return 1;
+       }
+       atexit(cleanup);
+
+       glutMainLoop();
+       return 0;
+}
+
+
+int init(void)
+{
+       float amb[] = {0.05, 0.05, 0.08, 1};
+
+       glEnable(GL_CULL_FACE);
+       glEnable(GL_DEPTH_TEST);
+       glEnable(GL_LIGHTING);
+       glEnable(GL_LIGHT0);
+       glEnable(GL_LIGHT1);
+       glEnable(GL_LIGHT2);
+
+       glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amb);
+
+       if(!(scn = cmesh_alloc()) || cmesh_load(scn, "gimbal.obj") == -1) {
+               fprintf(stderr, "failed to load scene file\n");
+               return -1;
+       }
+       return 0;
+}
+
+void cleanup(void)
+{
+       cmesh_free(scn);
+}
+
+void display(void)
+{
+       static const float lpos[][4] = {
+               {-100, 100, 200, 1},
+               {100, 80, 50, 1},
+               {20, -50, -150, 1}
+       };
+       static const float lcol[][4] = {
+               {0.9, 0.9, 0.9, 1},
+               {0.5, 0.3, 0.2, 1},
+               {0.2, 0.3, 0.2, 1}
+       };
+       int i;
+
+       glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+       glMatrixMode(GL_MODELVIEW);
+       glLoadIdentity();
+       glTranslatef(0, 0, -cam_dist);
+       glRotatef(cam_phi, 1, 0, 0);
+       glRotatef(cam_theta, 0, 1, 0);
+
+       for(i=0; i<3; i++) {
+               glLightfv(GL_LIGHT0 + i, GL_POSITION, lpos[i]);
+               glLightfv(GL_LIGHT0 + i, GL_DIFFUSE, lcol[i]);
+       }
+
+       cmesh_draw(scn);
+
+       glutSwapBuffers();
+}
+void idle(void)
+{
+       glutPostRedisplay();
+}
+
+void reshape(int x, int y)
+{
+       glViewport(0, 0, x, y);
+       glMatrixMode(GL_PROJECTION);
+       glLoadIdentity();
+       gluPerspective(50.0, (float)x / (float)y, 0.5, 500.0);
+}
+
+void keyb(unsigned char key, int x, int y)
+{
+       switch(key) {
+       case 27:
+               exit(0);
+       }
+}
+
+void mouse(int bn, int st, int x, int y)
+{
+       prev_mx = x;
+       prev_my = y;
+       bnstate[bn - GLUT_LEFT_BUTTON] = st == GLUT_DOWN;
+}
+
+void motion(int x, int y)
+{
+       int dx = x - prev_mx;
+       int dy = y - prev_my;
+       prev_mx = x;
+       prev_my = y;
+
+       if(!(dx | dy)) return;
+
+       if(bnstate[0]) {
+               cam_theta += dx * 0.5;
+               cam_phi += dy * 0.5;
+               if(cam_phi < -90) cam_phi = -90;
+               if(cam_phi > 90) cam_phi = 90;
+       }
+
+       if(bnstate[2]) {
+               cam_dist += dy * 0.1;
+               if(cam_dist < 0.0f) cam_dist = 0.0f;
+       }
+}
+
+void sball_motion(int x, int y, int z)
+{
+}
+
+void sball_rotate(int rx, int ry, int rz)
+{
+}
+
+void sball_button(int bn, int st)
+{
+}
diff --git a/tools/ropesim/src/meshload.c b/tools/ropesim/src/meshload.c
new file mode 100644 (file)
index 0000000..3a1fc70
--- /dev/null
@@ -0,0 +1,398 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <assert.h>
+#include "cmesh.h"
+
+#ifdef USE_ASSIMP
+#include <assimp/cimport.h>
+#include <assimp/postprocess.h>
+#include <assimp/mesh.h>
+#include <assimp/scene.h>
+#include <assimp/types.h>
+#else
+#include "dynarr.h"
+#include "rbtree.h"
+#endif
+
+
+#ifdef USE_ASSIMP
+
+static int add_mesh(struct cmesh *mesh, struct aiMesh *aimesh);
+
+#define AIPPFLAGS \
+       (aiProcess_JoinIdenticalVertices | aiProcess_PreTransformVertices | \
+        aiProcess_Triangulate | aiProcess_SortByPType | aiProcess_FlipUVs)
+
+int cmesh_load(struct cmesh *mesh, const char *fname)
+{
+       int i;
+       const struct aiScene *aiscn;
+
+       if(!(aiscn = aiImportFile(fname, AIPPFLAGS))) {
+               fprintf(stderr, "failed to open mesh file: %s\n", fname);
+               return -1;
+       }
+
+       for(i=0; i<(int)aiscn->mNumMeshes; i++) {
+               add_mesh(mesh, aiscn->mMeshes[i]);
+       }
+
+       aiReleaseImport(aiscn);
+       return 0;
+}
+
+static int add_mesh(struct cmesh *mesh, struct aiMesh *aim)
+{
+       int i, j, voffs, foffs;
+
+       voffs = cmesh_attrib_count(mesh, CMESH_ATTR_VERTEX);
+       foffs = cmesh_poly_count(mesh);
+
+       for(i=0; i<aim->mNumVertices; i++) {
+               struct aiVector3D *v = aim->mVertices + i;
+               cmesh_push_attrib3f(mesh, CMESH_ATTR_VERTEX, v->x, v->y, v->z);
+
+               if(aim->mNormals) {
+                       v = aim->mNormals + i;
+                       cmesh_push_attrib3f(mesh, CMESH_ATTR_NORMAL, v->x, v->y, v->z);
+               }
+               if(aim->mTangents) {
+                       v = aim->mTangents + i;
+                       cmesh_push_attrib3f(mesh, CMESH_ATTR_TANGENT, v->x, v->y, v->z);
+               }
+               if(aim->mColors[0]) {
+                       struct aiColor4D *col = aim->mColors[0] + i;
+                       cmesh_push_attrib4f(mesh, CMESH_ATTR_COLOR, col->r, col->g, col->b, col->a);
+               }
+               if(aim->mTextureCoords[0]) {
+                       v = aim->mTextureCoords[0] + i;
+                       cmesh_push_attrib2f(mesh, CMESH_ATTR_TEXCOORD, v->x, v->y);
+               }
+               if(aim->mTextureCoords[1]) {
+                       v = aim->mTextureCoords[1] + i;
+                       cmesh_push_attrib2f(mesh, CMESH_ATTR_TEXCOORD2, v->x, v->y);
+               }
+       }
+
+       if(aim->mFaces) {
+               for(i=0; i<aim->mNumFaces; i++) {
+                       assert(aim->mFaces[i].mNumIndices == 3);
+                       for(j=0; j<3; j++) {
+                               cmesh_push_index(mesh, aim->mFaces[i].mIndices[j] + voffs);
+                       }
+               }
+               cmesh_submesh(mesh, aim->mName.data, foffs, aim->mNumFaces);
+       }
+       return 0;
+}
+
+#else
+
+struct vertex_pos {
+       float x, y, z;
+};
+
+struct facevertex {
+       int vidx, tidx, nidx;
+};
+
+static char *clean_line(char *s);
+static char *parse_face_vert(char *ptr, struct facevertex *fv, int numv, int numt, int numn);
+static int cmp_facevert(const void *ap, const void *bp);
+static void free_rbnode_key(struct rbnode *n, void *cls);
+
+/* merge of different indices per attribute happens during face processing.
+ *
+ * A triplet of (vertex index/texcoord index/normal index) is used as the key
+ * to search in a balanced binary search tree for vertex buffer index assigned
+ * to the same triplet if it has been encountered before. That index is
+ * appended to the index buffer.
+ *
+ * If a particular triplet has not been encountered before, a new vertex is
+ * appended to the vertex buffer. The index of this new vertex is appended to
+ * the index buffer, and also inserted into the tree for future searches.
+ */
+int cmesh_load(struct cmesh *mesh, const char *fname)
+{
+       int i, line_num = 0, result = -1;
+       int found_quad = 0;
+       FILE *fp = 0;
+       char buf[256];
+       struct vertex_pos *varr = 0;
+       cgm_vec3 *narr = 0;
+       cgm_vec2 *tarr = 0;
+       struct rbtree *rbtree = 0;
+       char *subname = 0;
+       int substart = 0, subcount = 0;
+
+       if(!(fp = fopen(fname, "rb"))) {
+               fprintf(stderr, "load_mesh: failed to open file: %s\n", fname);
+               goto err;
+       }
+
+       if(!(rbtree = rb_create(cmp_facevert))) {
+               fprintf(stderr, "load_mesh: failed to create facevertex binary search tree\n");
+               goto err;
+       }
+       rb_set_delete_func(rbtree, free_rbnode_key, 0);
+
+       if(!(varr = dynarr_alloc(0, sizeof *varr)) ||
+                       !(narr = dynarr_alloc(0, sizeof *narr)) ||
+                       !(tarr = dynarr_alloc(0, sizeof *tarr))) {
+               fprintf(stderr, "load_mesh: failed to allocate resizable vertex array\n");
+               goto err;
+       }
+
+       while(fgets(buf, sizeof buf, fp)) {
+               char *line = clean_line(buf);
+               ++line_num;
+
+               if(!*line) continue;
+
+               switch(line[0]) {
+               case 'v':
+                       if(isspace(line[1])) {
+                               /* vertex */
+                               struct vertex_pos v;
+                               int num;
+
+                               num = sscanf(line + 2, "%f %f %f", &v.x, &v.y, &v.z);
+                               if(num < 3) {
+                                       fprintf(stderr, "%s:%d: invalid vertex definition: \"%s\"\n", fname, line_num, line);
+                                       goto err;
+                               }
+                               if(!(varr = dynarr_push(varr, &v))) {
+                                       fprintf(stderr, "load_mesh: failed to resize vertex buffer\n");
+                                       goto err;
+                               }
+
+                       } else if(line[1] == 't' && isspace(line[2])) {
+                               /* texcoord */
+                               cgm_vec2 tc;
+                               if(sscanf(line + 3, "%f %f", &tc.x, &tc.y) != 2) {
+                                       fprintf(stderr, "%s:%d: invalid texcoord definition: \"%s\"\n", fname, line_num, line);
+                                       goto err;
+                               }
+                               tc.y = 1.0f - tc.y;
+                               if(!(tarr = dynarr_push(tarr, &tc))) {
+                                       fprintf(stderr, "load_mesh: failed to resize texcoord buffer\n");
+                                       goto err;
+                               }
+
+                       } else if(line[1] == 'n' && isspace(line[2])) {
+                               /* normal */
+                               cgm_vec3 norm;
+                               if(sscanf(line + 3, "%f %f %f", &norm.x, &norm.y, &norm.z) != 3) {
+                                       fprintf(stderr, "%s:%d: invalid normal definition: \"%s\"\n", fname, line_num, line);
+                                       goto err;
+                               }
+                               if(!(narr = dynarr_push(narr, &norm))) {
+                                       fprintf(stderr, "load_mesh: failed to resize normal buffer\n");
+                                       goto err;
+                               }
+                       }
+                       break;
+
+               case 'f':
+                       if(isspace(line[1])) {
+                               /* face */
+                               char *ptr = line + 2;
+                               struct facevertex fv;
+                               struct rbnode *node;
+                               int vsz = dynarr_size(varr);
+                               int tsz = dynarr_size(tarr);
+                               int nsz = dynarr_size(narr);
+
+                               for(i=0; i<4; i++) {
+                                       if(!(ptr = parse_face_vert(ptr, &fv, vsz, tsz, nsz))) {
+                                               if(i < 3 || found_quad) {
+                                                       fprintf(stderr, "%s:%d: invalid face definition: \"%s\"\n", fname, line_num, line);
+                                                       goto err;
+                                               } else {
+                                                       break;
+                                               }
+                                       }
+
+                                       if((node = rb_find(rbtree, &fv))) {
+                                               unsigned int idx = (unsigned int)node->data;
+                                               assert(idx < cmesh_attrib_count(mesh, CMESH_ATTR_VERTEX));
+                                               if(cmesh_push_index(mesh, idx) == -1) {
+                                                       fprintf(stderr, "load_mesh: failed to resize index array\n");
+                                                       goto err;
+                                               }
+                                               subcount++;     /* inc number of submesh indices, in case we have submeshes */
+                                       } else {
+                                               unsigned int newidx = cmesh_attrib_count(mesh, CMESH_ATTR_VERTEX);
+                                               struct facevertex *newfv;
+                                               struct vertex_pos *vptr = varr + fv.vidx;
+
+                                               if(cmesh_push_attrib3f(mesh, CMESH_ATTR_VERTEX, vptr->x, vptr->y, vptr->z) == -1) {
+                                                       fprintf(stderr, "load_mesh: failed to resize vertex array\n");
+                                                       goto err;
+                                               }
+                                               if(fv.nidx >= 0) {
+                                                       float nx = narr[fv.nidx].x;
+                                                       float ny = narr[fv.nidx].y;
+                                                       float nz = narr[fv.nidx].z;
+                                                       if(cmesh_push_attrib3f(mesh, CMESH_ATTR_NORMAL, nx, ny, nz) == -1) {
+                                                               fprintf(stderr, "load_mesh: failed to resize normal array\n");
+                                                               goto err;
+                                                       }
+                                               }
+                                               if(fv.tidx >= 0) {
+                                                       float tu = tarr[fv.tidx].x;
+                                                       float tv = tarr[fv.tidx].y;
+                                                       if(cmesh_push_attrib2f(mesh, CMESH_ATTR_TEXCOORD, tu, tv) == -1) {
+                                                               fprintf(stderr, "load_mesh: failed to resize texcoord array\n");
+                                                               goto err;
+                                                       }
+                                               }
+
+                                               if(cmesh_push_index(mesh, newidx) == -1) {
+                                                       fprintf(stderr, "load_mesh: failed to resize index array\n");
+                                                       goto err;
+                                               }
+                                               subcount++;     /* inc number of submesh indices, in case we have submeshes */
+
+                                               if((newfv = malloc(sizeof *newfv))) {
+                                                       *newfv = fv;
+                                               }
+                                               if(!newfv || rb_insert(rbtree, newfv, (void*)newidx) == -1) {
+                                                       fprintf(stderr, "load_mesh: failed to insert facevertex to the binary search tree\n");
+                                                       goto err;
+                                               }
+                                       }
+                               }
+                               if(i > 3) found_quad = 1;
+                       }
+                       break;
+
+               case 'o':
+                       if(subcount > 0) {
+                               printf("adding submesh: %s\n", subname);
+                               cmesh_submesh(mesh, subname, substart / 3, subcount / 3);
+                       }
+                       free(subname);
+                       if((subname = malloc(strlen(line)))) {
+                               strcpy(subname, clean_line(line + 2));
+                       }
+                       substart += subcount;
+                       subcount = 0;
+                       break;
+
+               default:
+                       break;
+               }
+       }
+
+       if(subcount > 0) {
+               /* don't add the final submesh if we never found another. an obj file with a
+                * single 'o' for the whole list of faces, is a single mesh without submeshes
+                */
+               if(cmesh_submesh_count(mesh) > 0) {
+                       printf("adding submesh: %s\n", subname);
+                       cmesh_submesh(mesh, subname, substart / 3, subcount / 3);
+               } else {
+                       /* ... but use the 'o' name as the name of the mesh instead of the filename */
+                       if(subname && *subname) {
+                               cmesh_set_name(mesh, subname);
+                       }
+               }
+       }
+
+       result = 0;     /* success */
+
+       printf("loaded %s mesh: %s (%d submeshes): %d vertices, %d faces\n",
+                       found_quad ? "quad" : "triangle", fname, cmesh_submesh_count(mesh),
+                       cmesh_attrib_count(mesh, CMESH_ATTR_VERTEX), cmesh_poly_count(mesh));
+
+err:
+       if(fp) fclose(fp);
+       dynarr_free(varr);
+       dynarr_free(narr);
+       dynarr_free(tarr);
+       rb_free(rbtree);
+       free(subname);
+       return result;
+}
+
+
+static char *clean_line(char *s)
+{
+       char *end;
+
+       while(*s && isspace(*s)) ++s;
+       if(!*s) return 0;
+
+       end = s;
+       while(*end && *end != '#') ++end;
+       *end-- = 0;
+
+       while(end > s && isspace(*end)) {
+               *end-- = 0;
+       }
+
+       return s;
+}
+
+static char *parse_idx(char *ptr, int *idx, int arrsz)
+{
+       char *endp;
+       int val = strtol(ptr, &endp, 10);
+       if(endp == ptr) return 0;
+
+       if(val < 0) {   /* convert negative indices */
+               *idx = arrsz + val;
+       } else {
+               *idx = val - 1; /* indices in obj are 1-based */
+       }
+       return endp;
+}
+
+/* possible face-vertex definitions:
+ * 1. vertex
+ * 2. vertex/texcoord
+ * 3. vertex//normal
+ * 4. vertex/texcoord/normal
+ */
+static char *parse_face_vert(char *ptr, struct facevertex *fv, int numv, int numt, int numn)
+{
+       if(!(ptr = parse_idx(ptr, &fv->vidx, numv)))
+               return 0;
+       if(*ptr != '/') return (!*ptr || isspace(*ptr)) ? ptr : 0;
+
+       if(*++ptr == '/') {     /* no texcoord */
+               fv->tidx = -1;
+               ++ptr;
+       } else {
+               if(!(ptr = parse_idx(ptr, &fv->tidx, numt)))
+                       return 0;
+               if(*ptr != '/') return (!*ptr || isspace(*ptr)) ? ptr : 0;
+               ++ptr;
+       }
+
+       if(!(ptr = parse_idx(ptr, &fv->nidx, numn)))
+               return 0;
+       return (!*ptr || isspace(*ptr)) ? ptr : 0;
+}
+
+static int cmp_facevert(const void *ap, const void *bp)
+{
+       const struct facevertex *a = ap;
+       const struct facevertex *b = bp;
+
+       if(a->vidx == b->vidx) {
+               if(a->tidx == b->tidx) {
+                       return a->nidx - b->nidx;
+               }
+               return a->tidx - b->tidx;
+       }
+       return a->vidx - b->vidx;
+}
+
+static void free_rbnode_key(struct rbnode *n, void *cls)
+{
+       free(n->key);
+}
+#endif
diff --git a/tools/ropesim/src/opengl.h b/tools/ropesim/src/opengl.h
new file mode 100644 (file)
index 0000000..58d3a8c
--- /dev/null
@@ -0,0 +1,7 @@
+#ifndef OPENGL_H_
+#define OPENGL_H_
+
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+
+#endif /* OPENGL_H_ */