Merge pull request #16069 from unknownbrackets/depth-clamp

GPU: Simplify depth clamped clip planes
hrydgard · Sep 21, 2022 · 3ff400e · 3ff400e
2 parents 95ea045 + f8d29fd
commit 3ff400e
Showing 1 changed file with 4 additions and 7 deletions.
diff --git a/GPU/Common/VertexShaderGenerator.cpp b/GPU/Common/VertexShaderGenerator.cpp
@@ -1189,37 +1189,34 @@ bool GenerateVertexShader(const VShaderID &id, char *buffer, const ShaderLanguag
 			WRITE(p, "  %sv_fogdepth = (viewPos.z + u_fogcoef.x) * u_fogcoef.y;\n", compat.vsOutPrefix);
 	}
 
-	if (clipClampedDepth || (vertexRangeCulling && !IsVRBuild())) {
-		WRITE(p, "  vec3 projPos = outPos.xyz / outPos.w;\n");
-	}
-
 	if (clipClampedDepth) {
 		const char *clip0 = compat.shaderLanguage == HLSL_D3D11 ? ".x" : "[0]";
 		const char *clip1 = compat.shaderLanguage == HLSL_D3D11 ? ".y" : "[1]";
-		WRITE(p, "  mediump float integerZ = projPos.z * u_depthRange.x + u_depthRange.y;\n");
 
 		// This should clip against minz, but only when it's above zero.
 		if (ShaderLanguageIsOpenGL(compat.shaderLanguage)) {
 			// On OpenGL/GLES, these values account for the -1 -> 1 range.
 			WRITE(p, "  if (u_depthRange.y - u_depthRange.x >= 1.0) {\n");
+			WRITE(p, "    %sgl_ClipDistance%s = outPos.w + outPos.z;\n", compat.vsOutPrefix, clip0);
 		} else {
 			// Everywhere else, it's 0 -> 1, simpler.
 			WRITE(p, "  if (u_depthRange.y >= 1.0) {\n");
+			WRITE(p, "    %sgl_ClipDistance%s = outPos.z;\n", compat.vsOutPrefix, clip0);
 		}
-		WRITE(p, "    %sgl_ClipDistance%s = integerZ * outPos.w;\n", compat.vsOutPrefix, clip0);
 		WRITE(p, "  } else {\n");
 		WRITE(p, "    %sgl_ClipDistance%s = 0.0;\n", compat.vsOutPrefix, clip0);
 		WRITE(p, "  }\n");
 
 		// This is similar, but for maxz when it's below 65535.0.  -1/0 don't matter here.
 		WRITE(p, "  if (u_depthRange.x + u_depthRange.y <= 65534.0) {\n");
-		WRITE(p, "    %sgl_ClipDistance%s = (65535.0 - integerZ) * outPos.w;\n", compat.vsOutPrefix, clip1);
+		WRITE(p, "    %sgl_ClipDistance%s = outPos.w - outPos.z;\n", compat.vsOutPrefix, clip1);
 		WRITE(p, "  } else {\n");
 		WRITE(p, "    %sgl_ClipDistance%s = 0.0;\n", compat.vsOutPrefix, clip1);
 		WRITE(p, "  }\n");
 	}
 
 	if (vertexRangeCulling && !IsVRBuild()) {
+		WRITE(p, "  vec3 projPos = outPos.xyz / outPos.w;\n");
 		WRITE(p, "  float projZ = (projPos.z - u_depthRange.z) * u_depthRange.w;\n");
 		// Vertex range culling doesn't happen when Z clips, note sign of w is important.
 		WRITE(p, "  if (u_cullRangeMin.w <= 0.0 || projZ * outPos.w > -outPos.w) {\n");