postfx materials now support sRGB emulation in FL0

FIXES=[498317018]

Author: pixelflinger

libs/filamat/src/shaders/ShaderGenerator.cpp

@@ -250,7 +250,9 @@ void ShaderGenerator::generateVertexDomainDefines(io::sstream& out, VertexDomain
 }
 
 void ShaderGenerator::generatePostProcessMaterialVariantDefines(io::sstream& out,
-        PostProcessVariant const variant) noexcept {
+        ShaderStage const, MaterialBuilder::FeatureLevel const featureLevel,
+        MaterialInfo const&, PostProcessVariant const variant) noexcept {
+    CodeGenerator::generateDefine(out, "MATERIAL_FEATURE_LEVEL", uint32_t(featureLevel));
     switch (variant) {
         case PostProcessVariant::OPAQUE:
             CodeGenerator::generateDefine(out, "POST_PROCESS_OPAQUE", 1u);
@@ -737,7 +739,8 @@ std::string ShaderGenerator::createPostProcessVertexProgram(ShaderModel const sm
     }
 
     CodeGenerator::generatePostProcessInputs(vs, ShaderStage::VERTEX);
-    generatePostProcessMaterialVariantDefines(vs, PostProcessVariant(variantKey));
+    generatePostProcessMaterialVariantDefines(vs, ShaderStage::VERTEX,
+            featureLevel, material, PostProcessVariant(variantKey));
 
     cg.generateUniforms(vs, ShaderStage::VERTEX,
             DescriptorSetBindingPoints::PER_VIEW,
@@ -765,14 +768,16 @@ std::string ShaderGenerator::createPostProcessVertexProgram(ShaderModel const sm
 std::string ShaderGenerator::createPostProcessFragmentProgram(ShaderModel const sm,
         MaterialBuilder::TargetApi const targetApi, MaterialBuilder::TargetLanguage const targetLanguage,
         MaterialBuilder::FeatureLevel const featureLevel,
-        MaterialInfo const& material, uint8_t variant, uint32_t apiLevel) const noexcept {
+        MaterialInfo const& material, filament::Variant::type_t variantKey,
+        uint32_t apiLevel) const noexcept {
     const CodeGenerator cg(sm, targetApi, targetLanguage, featureLevel);
     io::sstream fs;
     cg.generateCommonProlog(fs, ShaderStage::FRAGMENT, material, {}, apiLevel);
 
     generateUserSpecConstants(cg, fs, mConstants);
 
-    generatePostProcessMaterialVariantDefines(fs, PostProcessVariant(variant));
+    generatePostProcessMaterialVariantDefines(fs, ShaderStage::FRAGMENT,
+            featureLevel, material, PostProcessVariant(variantKey));
 
     // custom material variables
     size_t variableIndex = 0;

libs/filamat/src/shaders/ShaderGenerator.h

@@ -102,7 +102,9 @@ class ShaderGenerator {
             MaterialInfo const& material, filament::Variant variant) noexcept;
 
     static void generatePostProcessMaterialVariantDefines(utils::io::sstream& out,
-            filament::PostProcessVariant variant) noexcept;
+            filament::backend::ShaderStage stage,
+            MaterialBuilder::FeatureLevel featureLevel,
+            MaterialInfo const& material, filament::PostProcessVariant variant) noexcept;
 
     static void generateUserSpecConstants(
             const CodeGenerator& cg, utils::io::sstream& fs,
@@ -117,7 +119,8 @@ class ShaderGenerator {
     std::string createPostProcessFragmentProgram(filament::backend::ShaderModel sm,
             MaterialBuilder::TargetApi targetApi, MaterialBuilder::TargetLanguage targetLanguage,
             MaterialBuilder::FeatureLevel featureLevel,
-            MaterialInfo const& material, uint8_t variant, uint32_t apiLevel) const noexcept;
+            MaterialInfo const& material, filament::Variant::type_t variantKey,
+            uint32_t apiLevel) const noexcept;
 
     static void appendShader(utils::io::sstream& ss,
             const utils::CString& shader, size_t lineOffset) noexcept;

shaders/src/post_process_main.fs

@@ -4,6 +4,14 @@ void main() {
     // Invoke user code
     postProcess(inputs);
 
+#if MATERIAL_FEATURE_LEVEL == 0
+    if (CONFIG_SRGB_SWAPCHAIN_EMULATION) {
+        if (frameUniforms.rec709 != 0) {
+            inputs.FRAG_OUTPUT0.rgb = pow(inputs.FRAG_OUTPUT0.rgb, vec3(0.45454));
+        }
+    }
+#endif
+
 #if defined(FRAG_OUTPUT0)
     FRAG_OUTPUT_AT0 FRAG_OUTPUT_SWIZZLE0 = inputs.FRAG_OUTPUT0;
 #endif

shaders/src/surface_main.fs

@@ -114,9 +114,7 @@ void main() {
 #if MATERIAL_FEATURE_LEVEL == 0
     if (CONFIG_SRGB_SWAPCHAIN_EMULATION) {
         if (frameUniforms.rec709 != 0) {
-            fragColor.r = pow(fragColor.r, 0.45454);
-            fragColor.g = pow(fragColor.g, 0.45454);
-            fragColor.b = pow(fragColor.b, 0.45454);
+            fragColor.rgb = pow(fragColor.rgb, vec3(0.45454));
         }
     }
 #endif