From: John Tsiombikas <nuclear@member.fsf.org>
Date: Sun, 26 Aug 2018 12:18:44 +0000 (+0300)
Subject: reflection
X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=dosrtxon;a=commitdiff_plain;h=584c6161bb6f3f548d5e27bb7d6895a81375881e

reflection
---

diff --git a/src/3dgfx.c b/src/3dgfx.c
index 044ab66..64fd604 100644
--- a/src/3dgfx.c
+++ b/src/3dgfx.c
@@ -82,6 +82,7 @@ int g3d_init(void)
 		fprintf(stderr, "failed to allocate G3D context\n");
 		return -1;
 	}
+	st->opt = G3D_CLIP_FRUSTUM;
 	st->fill_mode = POLYFILL_FLAT;
 
 	for(i=0; i<G3D_NUM_MATRICES; i++) {
@@ -438,17 +439,19 @@ void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
 		}
 
 		/* clipping */
-		for(i=0; i<6; i++) {
-			memcpy(tmpv, v, vnum * sizeof *v);
-
-			if(clip_frustum(v, &vnum, tmpv, vnum, i) < 0) {
-				/* polygon completely outside of view volume. discard */
-				vnum = 0;
-				break;
+		if(st->opt & G3D_CLIP_FRUSTUM) {
+			for(i=0; i<6; i++) {
+				memcpy(tmpv, v, vnum * sizeof *v);
+
+				if(clip_frustum(v, &vnum, tmpv, vnum, i) < 0) {
+					/* polygon completely outside of view volume. discard */
+					vnum = 0;
+					break;
+				}
 			}
-		}
 
-		if(!vnum) continue;
+			if(!vnum) continue;
+		}
 
 		for(i=0; i<vnum; i++) {
 			if(v[i].w != 0.0f) {
diff --git a/src/3dgfx.h b/src/3dgfx.h
index 2a82284..07a3aea 100644
--- a/src/3dgfx.h
+++ b/src/3dgfx.h
@@ -19,16 +19,21 @@ enum {
 
 /* g3d_enable/g3d_disable bits */
 enum {
-	G3D_CULL_FACE	= 0x0001,
-	G3D_DEPTH_TEST	= 0x0002,	/* XXX not implemented */
-	G3D_LIGHTING	= 0x0004,
-	G3D_LIGHT0		= 0x0008,
-	G3D_LIGHT1		= 0x0010,
-	G3D_LIGHT2		= 0x0020,
-	G3D_LIGHT3		= 0x0040,
-	G3D_TEXTURE		= 0x0080,
-	G3D_BLEND		= 0x0100,
-	G3D_TEXTURE_GEN	= 0x0200,
+	G3D_CULL_FACE	= 0x000001,
+	G3D_DEPTH_TEST	= 0x000002,	/* XXX not implemented */
+	G3D_LIGHTING	= 0x000004,
+	G3D_LIGHT0		= 0x000008,
+	G3D_LIGHT1		= 0x000010,
+	G3D_LIGHT2		= 0x000020,
+	G3D_LIGHT3		= 0x000040,
+	G3D_TEXTURE		= 0x000080,
+	G3D_BLEND		= 0x000100,
+	G3D_TEXTURE_GEN	= 0x000200,
+	G3D_CLIP_FRUSTUM = 0x000800,/* when disabled, don't clip against the frustum */
+	G3D_CLIP_PLANE0 = 0x001000,	/* user-defined 3D clipping planes XXX not impl. */
+	G3D_CLIP_PLANE1 = 0x002000,
+	G3D_CLIP_PLANE2 = 0x004000,
+	G3D_CLIP_PLANE3 = 0x008000,
 
 	G3D_ALL = 0x7fffffff
 };
diff --git a/src/parts/rtxonoff.c b/src/parts/rtxonoff.c
index 14edf1c..bab4d98 100644
--- a/src/parts/rtxonoff.c
+++ b/src/parts/rtxonoff.c
@@ -33,6 +33,10 @@ static const char *cartex_fname[2] = {"data/ldiablo.png", 0};
 static struct g3d_mesh mesh_car[2];
 static struct pimage tex_car[2];
 
+static int shading = G3D_TEX_GOURAUD;
+static int do_clip = 1;
+
+
 struct screen *rtxonoff_screen(void)
 {
 	return &scr;
@@ -80,6 +84,8 @@ static void start(long trans_time)
 	g3d_enable(G3D_CULL_FACE);
 	g3d_enable(G3D_LIGHTING);
 	g3d_enable(G3D_LIGHT0);
+
+	g3d_polygon_mode(shading);
 }
 
 static void update(void)
@@ -103,20 +109,50 @@ static void draw(void)
 	g3d_rotate(cam_phi, 1, 0, 0);
 	g3d_rotate(cam_theta, 0, 1, 0);
 
-	g3d_polygon_mode(G3D_TEX_GOURAUD);
+	g3d_set_texture(tex_car[0].width, tex_car[0].height, tex_car[0].pixels);
+	zsort_mesh(&mesh_car[0]);
 
-	for(i=0; i<sizeof mesh_car / sizeof mesh_car[0]; i++) {
-		if(mesh_car[i].varr) {
-			g3d_set_texture(tex_car[i].width, tex_car[i].height, tex_car[i].pixels);
+	g3d_light_color(0, 0.3, 0.3, 0.3);
+	g3d_push_matrix();
+	g3d_scale(1, -1, 1);
+	g3d_front_face(G3D_CW);
+	draw_mesh(&mesh_car[0]);
+	g3d_front_face(G3D_CCW);
+	g3d_pop_matrix();
 
-			zsort_mesh(&mesh_car[i]);
-			draw_mesh(&mesh_car[i]);
-		}
-	}
+	g3d_light_color(0, 1, 1, 1);
+	draw_mesh(&mesh_car[0]);
 
 	swap_buffers(fb_pixels);
 }
 
 static void keypress(int key)
 {
+	static int lighting = 1;
+	static int clipping = 1;
+
+	switch(key) {
+	case ' ':
+		shading = (shading + 1) % 5;
+		g3d_polygon_mode(shading);
+		break;
+
+	case 'l':
+		lighting = !lighting;
+		if(lighting) {
+			g3d_enable(G3D_LIGHTING);
+		} else {
+			g3d_disable(G3D_LIGHTING);
+		}
+		break;
+
+	case 'c':
+		clipping = !clipping;
+		if(clipping) {
+			g3d_enable(G3D_CLIP_FRUSTUM);
+		} else {
+			g3d_disable(G3D_CLIP_FRUSTUM);
+		}
+		break;
+	}
 }
diff --git a/src/polytmpl.h b/src/polytmpl.h
index 12df420..d61ac8e 100644
--- a/src/polytmpl.h
+++ b/src/polytmpl.h
@@ -93,6 +93,12 @@ void POLYFILL(struct pvertex *pv, int nverts)
 		if(pv[i].y > pv[botidx].y) botidx = i;
 	}
 
+	int winding = 0;
+	for(i=0; i<nverts; i++) {
+		int next = NEXTIDX(i);
+		winding += (pv[next].x - pv[i].x) * (pv[next].y + pv[i].y);
+	}
+
 	/* +1 to avoid crashing due to off-by-one rounding errors in the rasterization */
 	left = alloca((pfill_fb.height + 1) * sizeof *left);
 	right = alloca((pfill_fb.height + 1) * sizeof *right);
@@ -133,9 +139,16 @@ void POLYFILL(struct pvertex *pv, int nverts)
 				if(idx < sltop) sltop = idx;
 			/*}*/
 		} else {
-			struct pvertex *edge = y0 > y1 ? left : right;
-			uint32_t res = SCANEDGE(pv + i, pv + next, edge);
-			uint32_t tmp = (res >> 16) & 0xffff;
+			struct pvertex *edge;
+			uint32_t res, tmp;
+
+			if(winding < 0) {
+				edge = y0 > y1 ? left : right;
+			} else {
+				edge = y0 > y1 ? right : left;
+			}
+			res = SCANEDGE(pv + i, pv + next, edge);
+			tmp = (res >> 16) & 0xffff;
 			if(tmp > slbot) slbot = tmp;
 			if((tmp = res & 0xffff) < sltop) {
 				sltop = tmp;