fixed near clip

[gbajam22] / src / xgl.c

diff --git a/src/xgl.c b/src/xgl.c
index 48db220..8f59d90 100644 (file)
--- a/src/xgl.c
+++ b/src/xgl.c
@@ -191,12 +191,12 @@ static void xform_norm(struct xvertex *out, const struct xvertex *in, const int3
 /* d = 1.0 / tan(fov/2) */
 #define PROJ_D 0x20000
 /* near Z = 0.5 */
-#define NEAR_Z 0x10000
+#define NEAR_Z 0x40000
 
 void xgl_draw(int prim, const struct xvertex *varr, int vcount)
 {
-       int i, cidx;
-       struct xvertex xv[4];
+       int i, cidx, clipnum;
+       struct xvertex xv[4], xvclip[8];
        struct pvertex pv[4];
        int32_t ndotl;
 
@@ -233,15 +233,15 @@ void xgl_draw(int prim, const struct xvertex *varr, int vcount)
                }
 
                /* clip against near plane */
+               xgl_clip_near(xvclip, &clipnum, xv, prim);
 
-
-               for(i=0; i<prim; i++) {
+               for(i=0; i<clipnum; i++) {
                        /* viewport */
-                       pv[i].x = (((xv[i].x + 0x100) >> 1) * vp[2]) + (vp[0] << 8);
-                       pv[i].y = (((0x100 - xv[i].y) >> 1) * vp[3]) + (vp[1] << 8);
+                       pv[i].x = (((xvclip[i].x + 0x100) >> 1) * vp[2]) + (vp[0] << 8);
+                       pv[i].y = (((0x100 - xvclip[i].y) >> 1) * vp[3]) + (vp[1] << 8);
                }
 
-               polyfill_flat(pv, prim, cidx);
+               polyfill_flat(pv, clipnum, cidx);
 skip_poly:
                varr += prim;
                vcount -= prim;
@@ -293,13 +293,14 @@ void xgl_xyzzy(void)
        mat[mtop][12] = mat[mtop][13] = 0;
 }
 
-#define ISECT_NEAR(v0, v1)     ((((v0)->z - NEAR_Z) << 8) / (((v0)->z - (v1)->z) >> 8))
+/* 24.8 */
+#define ISECT_NEAR(v0, v1)     ((((v0)->z - NEAR_Z) << 8) / ((v0)->z - (v1)->z))
 
 #define LERP_VATTR(res, v0, v1, t) \
        do { \
-               (res)->x = (v0)->x + (((v1)->x - (v0)->x) >> 8) * (t);  \
-               (res)->y = (v0)->y + (((v1)->y - (v0)->y) >> 8) * (t);  \
-               (res)->z = (v0)->z + (((v1)->z - (v0)->z) >> 8) * (t);  \
+               (res)->x = (v0)->x + (((v1)->x - (v0)->x) * (t) >> 8);  \
+               (res)->y = (v0)->y + (((v1)->y - (v0)->y) * (t) >> 8);  \
+               (res)->z = (v0)->z + (((v1)->z - (v0)->nx) >> 8) * (t); \
                (res)->nx = (v0)->nx + (((v1)->nx - (v0)->nx) >> 8) * (t);      \
                (res)->ny = (v0)->ny + (((v1)->ny - (v0)->ny) >> 8) * (t);      \
                (res)->nz = (v0)->nz + (((v1)->nz - (v0)->nz) >> 8) * (t);      \