- clipper debugging

[dosdemo] / src / 3dgfx.c

diff --git a/src/3dgfx.c b/src/3dgfx.c
index 47b3830..46cc9ab 100644 (file)
--- a/src/3dgfx.c
+++ b/src/3dgfx.c
@@ -5,6 +5,7 @@
 #include <assert.h>
 #include "3dgfx.h"
 #include "polyfill.h"
+#include "polyclip.h"
 #include "inttypes.h"
 #include "util.h"
 
@@ -42,6 +43,8 @@ struct g3d_state {
 
        int width, height;
        void *pixels;
+
+       int vport[4];
 };
 
 static void xform4_vec3(const float *mat, float *vec);
@@ -94,6 +97,18 @@ void g3d_framebuffer(int width, int height, void *pixels)
        pfill_fb.pixels = pixels;
        pfill_fb.width = width;
        pfill_fb.height = height;
+
+       st->vport[0] = st->vport[1] = 0;
+       st->vport[2] = width;
+       st->vport[3] = height;
+}
+
+void g3d_viewport(int x, int y, int w, int h)
+{
+       st->vport[0] = x;
+       st->vport[1] = y;
+       st->vport[2] = w;
+       st->vport[3] = h;
 }
 
 void g3d_enable(unsigned int opt)
@@ -376,8 +391,8 @@ void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
                const int16_t *iarr, int iarr_size)
 {
        int i, j, nfaces;
-       struct pvertex pv[4];
-       struct g3d_vertex v[4];
+       struct pvertex pv[16];
+       struct g3d_vertex v[16];
        int vnum = prim; /* primitive vertex counts correspond to enum values */
        int mvtop = st->mtop[G3D_MODELVIEW];
        int ptop = st->mtop[G3D_PROJECTION];
@@ -402,7 +417,16 @@ void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
                        xform4_vec3(st->mat[G3D_PROJECTION][ptop], &v[i].x);
                }
 
-               /* TODO clipping */
+               /* clipping */
+               for(i=0; i<6; i++) {
+                       struct g3d_vertex orig[16];
+                       memcpy(orig, v, vnum * sizeof *v);
+
+                       if(clip_frustum(v, &vnum, orig, vnum, i) < 0) {
+                               /* polygon completely outside of view volume. discard */
+                               return;
+                       }
+               }
 
                for(i=0; i<vnum; i++) {
                        if(v[i].w != 0.0f) {
@@ -412,8 +436,8 @@ void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
                        }
 
                        /* viewport transformation */
-                       v[i].x = (v[i].x * 0.5f + 0.5f) * (float)st->width;
-                       v[i].y = (0.5f - v[i].y * 0.5f) * (float)st->height;
+                       v[i].x = (v[i].x * 0.5f + 0.5f) * (float)st->vport[2] + st->vport[0];
+                       v[i].y = (0.5f - v[i].y * 0.5f) * (float)st->vport[3] + st->vport[1];
 
                        /* convert pos to 24.8 fixed point */
                        pv[i].x = cround64(v[i].x * 256.0f);