Fix polygon offset depth clamp and units resolution.

src/OpenGL/libGLESv2/Context.cpp

@@ -2180,7 +2180,8 @@ template<typename T> bool Context::getIntegerv(GLenum pname, T *params) const
 		case GL_MAX_PROGRAM_TEXEL_OFFSET:
 			// Note: SwiftShader has no actual texel offset limit, so this limit can be modified if required.
 			// In any case, any behavior outside the specified range is valid since the spec mentions:
-			// (see OpenGL ES 3.0.5, 3.8.10.1 Scale Factor and Level of Detail, p.153)
			// "If any of the offset values are outside the range of the  implementation-defined values
+			// (see OpenGL ES 3.0.5, 3.8.10.1 Scale Factor and Level of Detail, p.153)
+			// "If any of the offset values are outside the range of the  implementation-defined values
 			//  MIN_PROGRAM_TEXEL_OFFSET and MAX_PROGRAM_TEXEL_OFFSET, results of the texture lookup are
 			//  undefined."
 			*params = MAX_PROGRAM_TEXEL_OFFSET;
@@ -2221,7 +2222,8 @@ template<typename T> bool Context::getIntegerv(GLenum pname, T *params) const
 		case GL_MIN_PROGRAM_TEXEL_OFFSET:
 			// Note: SwiftShader has no actual texel offset limit, so this limit can be modified if required.
 			// In any case, any behavior outside the specified range is valid since the spec mentions:
-			// (see OpenGL ES 3.0.5, 3.8.10.1 Scale Factor and Level of Detail, p.153)
			// "If any of the offset values are outside the range of the  implementation-defined values
+			// (see OpenGL ES 3.0.5, 3.8.10.1 Scale Factor and Level of Detail, p.153)
+			// "If any of the offset values are outside the range of the  implementation-defined values
 			//  MIN_PROGRAM_TEXEL_OFFSET and MAX_PROGRAM_TEXEL_OFFSET, results of the texture lookup are
 			//  undefined."
 			*params = MIN_PROGRAM_TEXEL_OFFSET;
@@ -2855,7 +2857,7 @@ void Context::applyState(GLenum drawMode)
 			if(depthbuffer)
 			{
 				device->setSlopeDepthBias(mState.polygonOffsetFactor);
-				float depthBias = ldexp(mState.polygonOffsetUnits, -(int)(depthbuffer->getDepthSize()));
+				float depthBias = ldexp(mState.polygonOffsetUnits, -23);   // We use 32-bit floating-point for all depth formats, with 23 mantissa bits.
 				device->setDepthBias(depthBias);
 			}
 		}

src/OpenGL/libGLESv2/utilities.cpp

@@ -1607,6 +1607,7 @@ namespace sw2es
 	//	case sw::FORMAT_D32_LOCKABLE:  return 0;
 	//	case sw::FORMAT_S8_LOCKABLE:   return 8;
 		default:
+			UNREACHABLE(stencilFormat);
 			return 0;
 		}
 	}
@@ -1642,6 +1643,7 @@ namespace sw2es
 		case sw::FORMAT_R5G6B5:
 			return 0;
 		default:
+			UNREACHABLE(colorFormat);
 			return 0;
 		}
 	}
@@ -1705,6 +1707,7 @@ namespace sw2es
 		case sw::FORMAT_R5G6B5:
 			return 5;
 		default:
+			UNREACHABLE(colorFormat);
 			return 0;
 		}
 	}
@@ -1759,6 +1762,7 @@ namespace sw2es
 		case sw::FORMAT_R5G6B5:
 			return 6;
 		default:
+			UNREACHABLE(colorFormat);
 			return 0;
 		}
 	}
@@ -1802,6 +1806,7 @@ namespace sw2es
 		case sw::FORMAT_R5G6B5:
 			return 5;
 		default:
+			UNREACHABLE(colorFormat);
 			return 0;
 		}
 	}
@@ -1827,7 +1832,9 @@ namespace sw2es
 	//	case sw::FORMAT_S8_LOCKABLE:    return 0;
 		case sw::FORMAT_D32FS8_SHADOW:
 		case sw::FORMAT_D32FS8_TEXTURE: return 32;
-		default:                        return 0;
+		default:
+			UNREACHABLE(depthFormat);
+			return 0;
 		}
 	}
 

src/Renderer/Context.cpp

@@ -276,6 +276,9 @@ namespace sw
 		cullMode = CULL_CLOCKWISE;
 		alphaReference = 0.0f;
 
+		depthBias = 0.0f;
+		slopeDepthBias = 0.0f;
+
 		for(int i = 0; i < RENDERTARGETS; i++)
 		{
 			colorWriteMask[i] = 0x0000000F;

src/Renderer/Context.hpp

@@ -434,6 +434,9 @@ namespace sw
 		CullMode cullMode;
 		float alphaReference;
 
+		float depthBias;
+		float slopeDepthBias;
+
 		TextureStage textureStage[8];
 		Sampler sampler[TOTAL_IMAGE_UNITS];
 

src/Renderer/PixelProcessor.cpp

@@ -990,6 +990,7 @@ namespace sw
 		state.pixelFogMode = context->pixelFogActive();
 		state.wBasedFog = context->wBasedFog && context->pixelFogActive() != FOG_NONE;
 		state.perspective = context->perspectiveActive();
+		state.depthClamp = (context->depthBias != 0.0f) || (context->slopeDepthBias != 0.0f);
 
 		if(context->alphaBlendActive())
 		{

src/Renderer/PixelProcessor.hpp

@@ -66,6 +66,7 @@ namespace sw
 			bool occlusionEnabled                     : 1;
 			bool wBasedFog                            : 1;
 			bool perspective                          : 1;
+			bool depthClamp                           : 1;
 
 			bool alphaBlendActive                     : 1;
 			BlendFactor sourceBlendFactor             : BITS(BLEND_LAST);

src/Renderer/Renderer.cpp

@@ -545,7 +545,7 @@ namespace sw
 
 				if(context->isDrawTriangle(false))
 				{
-					N += depthBias;
+					N += context->depthBias;
 				}
 
 				if(complementaryDepthBuffer)
@@ -583,7 +583,7 @@ namespace sw
 				data->halfPixelX = replicate(0.5f / W);
 				data->halfPixelY = replicate(0.5f / H);
 				data->viewportHeight = abs(viewport.height);
-				data->slopeDepthBias = slopeDepthBias;
+				data->slopeDepthBias = context->slopeDepthBias;
 				data->depthRange = Z;
 				data->depthNear = N;
 				draw->clipFlags = clipFlags;
@@ -2447,12 +2447,12 @@ namespace sw
 
 	void Renderer::setDepthBias(float bias)
 	{
-		depthBias = bias;
+		context->depthBias = bias;
 	}
 
 	void Renderer::setSlopeDepthBias(float slopeBias)
 	{
-		slopeDepthBias = slopeBias;
+		context->slopeDepthBias = slopeBias;
 	}
 
 	void Renderer::setRasterizerDiscard(bool rasterizerDiscard)

src/Renderer/SetupProcessor.cpp

@@ -85,7 +85,7 @@ namespace sw
 		state.pointSprite = context->pointSpriteActive();
 		state.cullMode = context->cullMode;
 		state.twoSidedStencil = context->stencilActive() && context->twoSidedStencil;
-		state.slopeDepthBias = slopeDepthBias != 0.0f;
+		state.slopeDepthBias = context->slopeDepthBias != 0.0f;
 		state.vFace = context->pixelShader && context->pixelShader->isVFaceDeclared();
 
 		state.positionRegister = Pos;

src/Renderer/SetupProcessor.hpp

@@ -95,9 +95,6 @@ namespace sw
 
 		void setRoutineCacheSize(int cacheSize);
 
-		float depthBias;
-		float slopeDepthBias;
-
 	private:
 		Context *const context;
 

src/Shader/PixelRoutine.cpp

@@ -95,6 +95,11 @@ namespace sw
 				}
 
 				z[q] = interpolate(x, Dz[q], z[q], primitive + OFFSET(Primitive,z), false, false);
+
+				if(state.depthClamp)
+				{
+					z[q] = Min(Max(z[q], Float4(0.0f)), Float4(1.0f));
+				}
 			}
 		}