--- /dev/null
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include "mesh.h"
+#include "3dgfx.h"
+
+int load_mesh(struct g3d_mesh *mesh, const char *fname)
+{
+ return -1; /* TODO */
+}
+
+static struct {
+ struct g3d_vertex *varr;
+ const float *xform;
+} zsort_cls;
+
+static int zsort_cmp(const void *aptr, const void *bptr)
+{
+ const float *m = zsort_cls.xform;
+
+ const struct g3d_vertex *va = (const struct g3d_vertex*)aptr;
+ const struct g3d_vertex *vb = (const struct g3d_vertex*)bptr;
+
+ float za = m[2] * va->x + m[6] * va->y + m[10] * va->z + m[14];
+ float zb = m[2] * vb->x + m[6] * vb->y + m[10] * vb->z + m[14];
+
+ ++va;
+ ++vb;
+
+ za += m[2] * va->x + m[6] * va->y + m[10] * va->z + m[14];
+ zb += m[2] * vb->x + m[6] * vb->y + m[10] * vb->z + m[14];
+
+ return za - zb;
+}
+
+static int zsort_indexed_cmp(const void *aptr, const void *bptr)
+{
+ const int16_t *a = (const int16_t*)aptr;
+ const int16_t *b = (const int16_t*)bptr;
+
+ const float *m = zsort_cls.xform;
+
+ const struct g3d_vertex *va = zsort_cls.varr + a[0];
+ const struct g3d_vertex *vb = zsort_cls.varr + b[0];
+
+ float za = m[2] * va->x + m[6] * va->y + m[10] * va->z + m[14];
+ float zb = m[2] * vb->x + m[6] * vb->y + m[10] * vb->z + m[14];
+
+ va = zsort_cls.varr + a[2];
+ vb = zsort_cls.varr + b[2];
+
+ za += m[2] * va->x + m[6] * va->y + m[10] * va->z + m[14];
+ zb += m[2] * vb->x + m[6] * vb->y + m[10] * vb->z + m[14];
+
+ return za - zb;
+}
+
+
+void zsort_mesh(struct g3d_mesh *m)
+{
+ zsort_cls.varr = m->varr;
+ zsort_cls.xform = g3d_get_matrix(G3D_MODELVIEW, 0);
+
+ if(m->iarr) {
+ int nfaces = m->icount / m->prim;
+ qsort(m->iarr, nfaces, m->prim * sizeof *m->iarr, zsort_indexed_cmp);
+ } else {
+ int nfaces = m->vcount / m->prim;
+ qsort(m->varr, nfaces, m->prim * sizeof *m->varr, zsort_cmp);
+ }
+}
+
+
+void draw_mesh(struct g3d_mesh *mesh)
+{
+ if(mesh->iarr) {
+ g3d_draw_indexed(mesh->prim, mesh->varr, mesh->vcount, mesh->iarr, mesh->icount);
+ } else {
+ g3d_draw(mesh->prim, mesh->varr, mesh->vcount);
+ }
+}
+
+
+#define NORMAL(vp, x, y, z) do { vp->nx = x; vp->ny = y; vp->nz = z; } while(0)
+#define COLOR(vp, cr, cg, cb) do { vp->r = cr; vp->g = cg; vp->b = cb; } while(0)
+#define TEXCOORD(vp, tu, tv) do { vp->u = tu; vp->v = tv; } while(0)
+#define VERTEX(vp, vx, vy, vz) \
+ do { \
+ vp->x = vx; vp->y = vy; vp->z = vz; vp->w = 1.0f; \
+ ++vp; \
+ } while(0)
+
+int gen_cube(struct g3d_mesh *mesh, float sz, int sub)
+{
+ struct g3d_vertex *vptr;
+ float hsz = sz / 2.0;
+
+ mesh->prim = G3D_QUADS;
+ mesh->iarr = 0;
+ mesh->icount = 0;
+
+ mesh->vcount = 24;
+ if(!(mesh->varr = malloc(mesh->vcount * sizeof *mesh->varr))) {
+ return -1;
+ }
+ vptr = mesh->varr;
+
+ /* -Z */
+ NORMAL(vptr, 0, 0, -1);
+ COLOR(vptr, 255, 0, 255);
+ VERTEX(vptr, hsz, -hsz, -hsz);
+ VERTEX(vptr, -hsz, -hsz, -hsz);
+ VERTEX(vptr, -hsz, hsz, -hsz);
+ VERTEX(vptr, hsz, hsz, -hsz);
+ /* -Y */
+ NORMAL(vptr, 0, -1, 0);
+ COLOR(vptr, 0, 255, 255);
+ VERTEX(vptr, -hsz, -hsz, -hsz);
+ VERTEX(vptr, hsz, -hsz, -hsz);
+ VERTEX(vptr, hsz, -hsz, hsz);
+ VERTEX(vptr, -hsz, -hsz, hsz);
+ /* -X */
+ NORMAL(vptr, -1, 0, 0);
+ COLOR(vptr, 255, 255, 0);
+ VERTEX(vptr, -hsz, -hsz, -hsz);
+ VERTEX(vptr, -hsz, -hsz, hsz);
+ VERTEX(vptr, -hsz, hsz, hsz);
+ VERTEX(vptr, -hsz, hsz, -hsz);
+ /* +X */
+ NORMAL(vptr, 1, 0, 0);
+ COLOR(vptr, 255, 0, 0);
+ VERTEX(vptr, hsz, -hsz, hsz);
+ VERTEX(vptr, hsz, -hsz, -hsz);
+ VERTEX(vptr, hsz, hsz, -hsz);
+ VERTEX(vptr, hsz, hsz, hsz);
+ /* +Y */
+ NORMAL(vptr, 0, 1, 0);
+ COLOR(vptr, 0, 255, 0);
+ VERTEX(vptr, -hsz, hsz, hsz);
+ VERTEX(vptr, hsz, hsz, hsz);
+ VERTEX(vptr, hsz, hsz, -hsz);
+ VERTEX(vptr, -hsz, hsz, -hsz);
+ /* +Z */
+ NORMAL(vptr, 0, 0, 1);
+ COLOR(vptr, 0, 0, 255);
+ VERTEX(vptr, -hsz, -hsz, hsz);
+ VERTEX(vptr, hsz, -hsz, hsz);
+ VERTEX(vptr, hsz, hsz, hsz);
+ VERTEX(vptr, -hsz, hsz, hsz);
+
+ return 0;
+}
+
+static void torusvec(float *res, float theta, float phi, float mr, float rr)
+{
+ float rx, ry, rz;
+ theta = -theta;
+
+ rx = -cos(phi) * rr + mr;
+ ry = sin(phi) * rr;
+ rz = 0.0f;
+
+ res[0] = rx * sin(theta) + rz * cos(theta);
+ res[1] = ry;
+ res[2] = -rx * cos(theta) + rz * sin(theta);
+}
+
+int gen_torus(struct g3d_mesh *mesh, float rad, float ringrad, int usub, int vsub)
+{
+ int i, j;
+ int nfaces, uverts, vverts;
+ struct g3d_vertex *vptr;
+ int16_t *iptr;
+
+ mesh->prim = G3D_QUADS;
+
+ if(usub < 4) usub = 4;
+ if(vsub < 2) vsub = 2;
+
+ uverts = usub + 1;
+ vverts = vsub + 1;
+
+ mesh->vcount = uverts * vverts;
+ nfaces = usub * vsub;
+ mesh->icount = nfaces * 4;
+
+ printf("generating torus with %d faces (%d vertices)\n", nfaces, mesh->vcount);
+
+ if(!(mesh->varr = malloc(mesh->vcount * sizeof *mesh->varr))) {
+ return -1;
+ }
+ if(!(mesh->iarr = malloc(mesh->icount * sizeof *mesh->iarr))) {
+ return -1;
+ }
+ vptr = mesh->varr;
+ iptr = mesh->iarr;
+
+ for(i=0; i<uverts; i++) {
+ float u = (float)i / (float)(uverts - 1);
+ float theta = u * 2.0 * M_PI;
+ float rcent[3];
+
+ torusvec(rcent, theta, 0, rad, 0);
+
+ for(j=0; j<vverts; j++) {
+ float v = (float)j / (float)(vverts - 1);
+ float phi = v * 2.0 * M_PI;
+ int chess = (i & 1) == (j & 1);
+
+ torusvec(&vptr->x, theta, phi, rad, ringrad);
+
+ vptr->nx = (vptr->x - rcent[0]) / ringrad;
+ vptr->ny = (vptr->y - rcent[1]) / ringrad;
+ vptr->nz = (vptr->z - rcent[2]) / ringrad;
+ vptr->u = u;
+ vptr->v = v;
+ vptr->r = chess ? 255 : 64;
+ vptr->g = 128;
+ vptr->b = chess ? 64 : 255;
+ ++vptr;
+
+ if(i < usub && j < vsub) {
+ int idx = i * vverts + j;
+ *iptr++ = idx;
+ *iptr++ = idx + 1;
+ *iptr++ = idx + vverts + 1;
+ *iptr++ = idx + vverts;
+ }
+ }
+ }
+ return 0;
+}
+
projects / dosdemo / blobdiff