Bug fix in invulnerability in Doom Software Render Mode and True Colo…

…r SW Render in SoftPoly.
ZDoom · Mar 27, 2021 · bf3018c · bf3018c
1 parent 4d35331
commit bf3018c
Showing 1 changed file with 21 additions and 13 deletions.
diff --git a/src/common/rendering/polyrenderer/drawers/screen_shader.cpp b/src/common/rendering/polyrenderer/drawers/screen_shader.cpp
@@ -538,12 +538,13 @@ static void MainFP(int x0, int x1, PolyTriangleThreadData* thread)
 			// frag = frag * vColor;
 			// frag.rgb = frag.rgb + uFogColor.rgb;
 
-			uint32_t startR = (int)((thread->mainVertexShader.Data.uObjectColor.r) * 255.0f);
-			uint32_t startG = (int)((thread->mainVertexShader.Data.uObjectColor.g) * 255.0f);
-			uint32_t startB = (int)((thread->mainVertexShader.Data.uObjectColor.b) * 255.0f);
-			uint32_t rangeR = (int)((thread->mainVertexShader.Data.uAddColor.r) * 255.0f) - startR;
-			uint32_t rangeG = (int)((thread->mainVertexShader.Data.uAddColor.g) * 255.0f) - startG;
-			uint32_t rangeB = (int)((thread->mainVertexShader.Data.uAddColor.b) * 255.0f) - startB;
+			// [GEC] I leave the default floating values.
+			float startR = thread->mainVertexShader.Data.uObjectColor.r;
+			float startG = thread->mainVertexShader.Data.uObjectColor.g;
+			float startB = thread->mainVertexShader.Data.uObjectColor.b;
+			float rangeR = thread->mainVertexShader.Data.uAddColor.r - startR;
+			float rangeG = thread->mainVertexShader.Data.uAddColor.g - startG;
+			float rangeB = thread->mainVertexShader.Data.uAddColor.b - startB;
 
 			for (int x = x0; x < x1; x++)
 			{
@@ -555,15 +556,22 @@ static void MainFP(int x0, int x1, PolyTriangleThreadData* thread)
 				uint32_t gray = (r * 77 + g * 143 + b * 37) >> 8;
 				gray += (gray >> 7); // gray*=256/255
 
-				r = (startR + ((gray * rangeR) >> 8)) << 1;
-				g = (startG + ((gray * rangeG) >> 8)) << 1;
-				b = (startB + ((gray * rangeB) >> 8)) << 1;
+				// [GEC] I use the same method as in shaders using floating values.
+				// This avoids errors in the invulneravility colormap in Doom and Heretic.
+				float fgray = (float)(gray / 255.f);
+				float fr = (startR + (fgray * rangeR)) * 2;
+				float fg = (startG + (fgray * rangeG)) * 2;
+				float fb = (startB + (fgray * rangeB)) * 2;
 
-				r = MIN(r, (uint32_t)255);
-				g = MIN(g, (uint32_t)255);
-				b = MIN(b, (uint32_t)255);
+				fr = clamp<float>(fr, 0.0f, 1.0f);
+				fg = clamp<float>(fg, 0.0f, 1.0f);
+				fb = clamp<float>(fb, 0.0f, 1.0f);
 
-				fragcolor[x] = MAKEARGB(a, r, g, b);
+				r = (uint32_t)(fr * 255.f);
+				g = (uint32_t)(fg * 255.f);
+				b = (uint32_t)(fb * 255.f);
+
+				fragcolor[x] = MAKEARGB(a, (uint8_t)r, (uint8_t)g, (uint8_t)b);
 			}
 		}
 		else