Improved rendering performance by disabling z-fight when a line super…

…cedes a primitive.
elfprince13 · Feb 8, 2016 · 35b18e5 · 35b18e5
1 parent 19ef652
commit 35b18e5
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Showing 2 changed files with 9 additions and 6 deletions.
diff --git a/ScanLineRender/ScanLineRender/Primitive.c b/ScanLineRender/ScanLineRender/Primitive.c
@@ -52,6 +52,7 @@ void makeQuad(Primitive *o, Color c, const Edge e1, const Edge e2, const Edge e3
 
 float getZForXY(const Primitive *p, float x, float y){
 	Point **const boundary = p->boundary;
+	float ret;
 	if(p->arity == 1){
 		const Point *const vs = boundary[START],
 		* ve = boundary[END];
@@ -71,7 +72,7 @@ float getZForXY(const Primitive *p, float x, float y){
 		const float xEst = (dx == 0) ? min(0,  dz) : (xNumer / dx),
 		yEst = (dy == 0) ? min(0,  dz) : (yNumer / dy);
 
-		return sz + (xEst + yEst) / 2;
+		ret = sz + (xEst + yEst) / 2;
 	} else {
 		Point **const e1 = boundary,
 		**const e2 = e1 + 1;
@@ -97,9 +98,9 @@ float getZForXY(const Primitive *p, float x, float y){
 		-nz * us->z,
 		numer = (-d - nx * x - ny * y);
 
-		return (nz == 0) ? ((numer > 0) ? HUGE_VAL : -HUGE_VAL) : (numer / nz) ;
+		ret = (nz == 0) ? ((numer > 0) ? HUGE_VAL : -HUGE_VAL) : (numer / nz) ;
 	}
-
+	return ret;
 }
 
 

diff --git a/ScanLineRender/ScanLineRender/ScanlineRenderer.c b/ScanLineRender/ScanLineRender/ScanlineRenderer.c
@@ -191,10 +191,12 @@ void render(Color *raster, int lineWidth, int numLines, const rb_red_blk_tree *s
 								if(++j == 1 || testZ <= bestZ){
 									dPrintf(("\t\tHit: %f <= %f || "SZF" == 1 for %s\n",testZ, bestZ, j,fmtColor(prim->color)));
 									if (testZ == bestZ && j != 1) {
-										zFight = true;
 										if (prim->arity == 1) {
+											zFight = curDraw->arity == 1;
 											curDraw = prim;
 											solitary = RBSetContains(&deFlags, prim);
+										} else {
+											zFight = curDraw->arity != 1;
 										}
 									} else {
 										zFight = false;
@@ -209,10 +211,10 @@ void render(Color *raster, int lineWidth, int numLines, const rb_red_blk_tree *s
 #ifndef NDEBUG
 								if(nextEdge || solitary){
 #endif
-									const int drawWidth = (zFight || solitary) ? 1 : ((nextEdge ? nextX : lineWidth) - curPixel),
+									const int drawWidth =  (zFight || solitary) ? 1 : ((nextEdge ? nextX : lineWidth) - curPixel),
 									stopPixel = curPixel + min(lineWidth - curPixel,
 															   max(0, drawWidth));
-									const Color drawColor = curDraw->color;
+									const Color drawColor = /*(uint16_t)roundOwn(63 * bestZ / 100) << 5;*/curDraw->color;
 									dPrintf(("Drawing %d @ (%d, %d)\n",drawWidth,curPixel,line));
 									dPrintf(("Drawing %d @ (%d, %d)\n",stopPixel - curPixel,curPixel,line));
 									while(curPixel < stopPixel){