#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <math.h>
#include "screen.h"
#include "demo.h"
#include "3dgfx.h"
struct mesh {
int prim;
struct g3d_vertex *varr;
- unsigned int *iarr;
+ int16_t *iarr;
int vcount, icount;
};
static void draw(void);
static void draw_mesh(struct mesh *mesh);
static int gen_cube(struct mesh *mesh, float sz);
+static int gen_torus(struct mesh *mesh, float rad, float ringrad, int usub, int vsub);
+static int dump_obj(const char *fname, struct mesh *m);
+static void zsort(struct mesh *m);
static struct screen scr = {
"polytest",
draw
};
-static struct mesh cube;
+static struct mesh cube, torus;
struct screen *polytest_screen(void)
{
static int init(void)
{
gen_cube(&cube, 1.0);
+ gen_torus(&torus, 1.0, 0.25, 24, 12);
+ dump_obj("torus.obj", &torus);
return 0;
}
g3d_rotate(phi, 1, 0, 0);
g3d_rotate(theta, 0, 1, 0);
- draw_mesh(&cube);
+ zsort(&torus);
+ draw_mesh(&torus);
}
static void draw_mesh(struct mesh *mesh)
{
if(mesh->iarr) {
- /*g3d_draw_indexed(mesh->prim, mesh->iarr, mesh->icount, mesh->varr);*/
+ g3d_draw_indexed(mesh->prim, mesh->varr, mesh->vcount, mesh->iarr, mesh->icount);
} else {
g3d_draw(mesh->prim, mesh->varr, mesh->vcount);
}
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);
+}
+
+static int gen_torus(struct 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;
+
+ 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;
+}
+
+static int dump_obj(const char *fname, struct mesh *m)
+{
+ int i, j, nfaces;
+ FILE *fp;
+ struct g3d_vertex *vptr;
+ int16_t *iptr;
+
+ if(!(fp = fopen(fname, "wb"))) {
+ return -1;
+ }
+
+ nfaces = m->icount / m->prim;
+ printf("dumping obj: %s - %d vertices / %d faces (%d indices)\n", fname,
+ m->vcount, nfaces, m->icount);
+
+ vptr = m->varr;
+ for(i=0; i<m->vcount; i++) {
+ fprintf(fp, "v %f %f %f\n", vptr->x, vptr->y, vptr->z);
+ ++vptr;
+ }
+ vptr = m->varr;
+ for(i=0; i<m->vcount; i++) {
+ fprintf(fp, "vn %f %f %f\n", vptr->nx, vptr->ny, vptr->nz);
+ ++vptr;
+ }
+ vptr = m->varr;
+ for(i=0; i<m->vcount; i++) {
+ fprintf(fp, "vt %f %f\n", vptr->u, vptr->v);
+ ++vptr;
+ }
+
+ iptr = m->iarr;
+ for(i=0; i<m->icount; i += m->prim) {
+ fputc('f', fp);
+ for(j=0; j<m->prim; j++) {
+ int idx = *iptr++ + 1;
+ fprintf(fp, " %d/%d/%d", idx, idx, idx);
+ }
+ fputc('\n', fp);
+ }
+
+ fclose(fp);
+ return 0;
+}
+
+static struct {
+ struct g3d_vertex *varr;
+ const float *xform;
+} zsort_cls;
+
+static int zsort_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;
+}
+
+static void zsort(struct mesh *m)
+{
+ int nfaces = m->icount / m->prim;
+
+ zsort_cls.varr = m->varr;
+ zsort_cls.xform = g3d_get_matrix(G3D_MODELVIEW, 0);
+
+ qsort(m->iarr, nfaces, m->prim * sizeof *m->iarr, zsort_cmp);
+}
projects / dosdemo / blobdiff