- use uAddColor instead of uObjectColor2 for the ending color of a special colormap range.

Unlike uObjectColor2, this is more global state. uObjectColor2 is part of gradient calculation which may later be offloaded to a secondary buffer which already resulted in only conditionally setting it, resulting in broken special colormap application for the software renderer.

src/rendering/gl/renderer/gl_renderstate.cpp

@@ -138,7 +138,7 @@ bool FGLRenderState::ApplyShader()
 	activeShader->muLightIndex.Set(-1);
 	activeShader->muClipSplit.Set(mClipSplit);
 	activeShader->muSpecularMaterial.Set(mGlossiness, mSpecularLevel);
-	activeShader->muAddColor.Set(mAddColor); // Can this be done without a shader?
+	activeShader->muAddColor.Set(mAddColor);
 
 	if (mGlowEnabled)
 	{

src/rendering/hwrenderer/utility/hw_draw2d.cpp

@@ -155,7 +155,7 @@ void Draw2D(F2DDrawer *drawer, FRenderState &state)
 		{
 			state.SetTextureMode(TM_FIXEDCOLORMAP);
 			state.SetObjectColor(cmd.mSpecialColormap[0]);
-			state.SetObjectColor2(cmd.mSpecialColormap[1]);
+			state.SetAddColor(cmd.mSpecialColormap[1]);
 		}
 		state.SetFog(cmd.mColor1, 0);
 		state.SetColor(1, 1, 1, 1, cmd.mDesaturate); 

wadsrc/static/shaders/glsl/main.fp

@@ -588,7 +588,7 @@ void main()
 		if (uTextureMode == 7)
 		{
 			float gray = grayscale(frag);
-			vec4 cm = (uObjectColor + gray * (uObjectColor2 - uObjectColor)) * 2;
+			vec4 cm = (uObjectColor + gray * (uAddColor - uObjectColor)) * 2;
 			frag = vec4(clamp(cm.rgb, 0.0, 1.0), frag.a);
 		}
 			frag = frag * ProcessLight(material, vColor);