Backport from gles3-dev: Disable line raster emulation on metal backend

kakashidinho · May 7, 2021 · 0708a75 · 0708a75
1 parent 9722c45
commit 0708a75
Show file tree

Hide file tree

Showing 3 changed files with 12 additions and 4 deletions.
diff --git a/include/GLSLANG/ShaderLang.h b/include/GLSLANG/ShaderLang.h
@@ -313,6 +313,11 @@ const ShCompileOptions SH_ADD_BASE_VERTEX_TO_VERTEX_ID = UINT64_C(1) << 48;
 // an emulation in shader is needed.
 const ShCompileOptions SH_METAL_EMULATE_LINEAR_DEPTH_RANGE_MAP = UINT64_C(1) << 49;
 
+// This flag indicates whether Bresenham line raster emulation code should be generated.  This
+// emulation is necessary if the backend uses a differnet algorithm to draw lines.  Currently only
+// implemented for the Vulkan backend.
+const ShCompileOptions SH_ADD_BRESENHAM_LINE_RASTER_EMULATION = UINT64_C(1) << 50;
+
 // Defines alternate strategies for implementing array index clamping.
 enum ShArrayIndexClampingStrategy
 {

diff --git a/src/compiler/translator/TranslatorVulkan.cpp b/src/compiler/translator/TranslatorVulkan.cpp
@@ -839,10 +839,13 @@ bool TranslatorVulkan::translateImpl(TIntermBlock *root,
             }
         }
 
-        if (!AddLineSegmentRasterizationEmulation(this, sink, root, &getSymbolTable(),
-                                                  driverUniforms, usesFragCoord))
+        if ((compileOptions & SH_ADD_BRESENHAM_LINE_RASTER_EMULATION) != 0)
         {
-            return false;
+            if (!AddLineSegmentRasterizationEmulation(this, sink, root, &getSymbolTable(),
+                                                      driverUniforms, usesFragCoord))
+            {
+                return false;
+            }
         }
 
         bool hasGLFragColor = false;

diff --git a/src/libANGLE/renderer/vulkan/ShaderVk.cpp b/src/libANGLE/renderer/vulkan/ShaderVk.cpp
@@ -25,7 +25,7 @@ std::shared_ptr<WaitableCompileEvent> ShaderVk::compile(const gl::Context *conte
                                                         gl::ShCompilerInstance *compilerInstance,
                                                         ShCompileOptions options)
 {
-    ShCompileOptions compileOptions = SH_INITIALIZE_UNINITIALIZED_LOCALS;
+    ShCompileOptions compileOptions = SH_INITIALIZE_UNINITIALIZED_LOCALS | SH_ADD_BRESENHAM_LINE_RASTER_EMULATION;
 
     ContextVk *contextVk = vk::GetImpl(context);