From b96e0ef63a7b5db7c3cf7c40d0ac509b3ee01eed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pablo=20Delgado=20Kr=C3=A4mer?= <private@pablode.com>
Date: Sat, 3 Aug 2024 19:30:10 +0200
Subject: [PATCH] gi: enable GLSL extensions using macros rather than generate
 new code

---
 src/gi/impl/Gi.cpp            |  2 +-
 src/gi/impl/GlslShaderGen.cpp | 10 ++--------
 src/gi/impl/GlslShaderGen.h   |  2 +-
 src/gi/impl/GlslStitcher.cpp  |  5 -----
 src/gi/impl/GlslStitcher.h    |  2 --
 src/gi/shaders/rp_main.rgen   |  9 +++++++++
 6 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/src/gi/impl/Gi.cpp b/src/gi/impl/Gi.cpp
index 9d3f4874..06aafff3 100644
--- a/src/gi/impl/Gi.cpp
+++ b/src/gi/impl/Gi.cpp
@@ -1196,7 +1196,7 @@ namespace gtl
         .nextEventEstimation = nextEventEstimation,
         .progressiveAccumulation = params.progressiveAccumulation,
         .reorderInvocations = s_deviceFeatures.rayTracingInvocationReorder,
-        .shaderClockExts = clockCyclesAov
+        .shaderClockExt = clockCyclesAov
       };
 
       std::vector<uint8_t> spv;
diff --git a/src/gi/impl/GlslShaderGen.cpp b/src/gi/impl/GlslShaderGen.cpp
index 99bc070b..8d3341af 100644
--- a/src/gi/impl/GlslShaderGen.cpp
+++ b/src/gi/impl/GlslShaderGen.cpp
@@ -74,18 +74,12 @@ namespace gtl
     GiGlslStitcher stitcher;
     stitcher.appendVersion();
 
-    if (params.shaderClockExts)
+    if (params.shaderClockExt)
     {
-      stitcher.appendRequiredExtension("GL_EXT_shader_explicit_arithmetic_types_int64");
-      stitcher.appendRequiredExtension("GL_ARB_shader_clock");
+      stitcher.appendDefine("REQUIRE_CLOCK");
     }
     if (params.reorderInvocations)
     {
-      stitcher.appendRequiredExtension("GL_NV_shader_invocation_reorder");
-      // For hit shader invocation reordering hint
-      stitcher.appendRequiredExtension("GL_EXT_buffer_reference");
-      stitcher.appendRequiredExtension("GL_EXT_buffer_reference_uvec2");
-
       uint32_t reoderHintValueCount = params.materialCount + 1/* no hit */;
       int32_t reorderHintBitCount = 0;
 
diff --git a/src/gi/impl/GlslShaderGen.h b/src/gi/impl/GlslShaderGen.h
index 049a03d1..dcdfcae7 100644
--- a/src/gi/impl/GlslShaderGen.h
+++ b/src/gi/impl/GlslShaderGen.h
@@ -72,7 +72,7 @@ namespace gtl
       bool nextEventEstimation;
       bool progressiveAccumulation;
       bool reorderInvocations;
-      bool shaderClockExts;
+      bool shaderClockExt;
     };
 
     struct MissShaderParams
diff --git a/src/gi/impl/GlslStitcher.cpp b/src/gi/impl/GlslStitcher.cpp
index a8789ffe..9ba53a91 100644
--- a/src/gi/impl/GlslStitcher.cpp
+++ b/src/gi/impl/GlslStitcher.cpp
@@ -67,11 +67,6 @@ namespace gtl
     m_source << "#define " << name << " " << value << "\n";
   }
 
-  void GiGlslStitcher::appendRequiredExtension(std::string_view name)
-  {
-    m_source << "#extension " << name << ": require\n";
-  }
-
   void GiGlslStitcher::appendString(std::string_view value)
   {
     m_source << value;
diff --git a/src/gi/impl/GlslStitcher.h b/src/gi/impl/GlslStitcher.h
index 2a98c616..f2d0a9cc 100644
--- a/src/gi/impl/GlslStitcher.h
+++ b/src/gi/impl/GlslStitcher.h
@@ -37,8 +37,6 @@ namespace gtl
     void appendDefine(std::string_view name, int32_t value);
     void appendDefine(std::string_view name, float value);
 
-    void appendRequiredExtension(std::string_view name);
-
     void appendString(std::string_view value);
 
     bool appendSourceFile(fs::path path);
diff --git a/src/gi/shaders/rp_main.rgen b/src/gi/shaders/rp_main.rgen
index 925e1ace..5de30725 100644
--- a/src/gi/shaders/rp_main.rgen
+++ b/src/gi/shaders/rp_main.rgen
@@ -6,8 +6,17 @@
 #extension GL_EXT_shader_explicit_arithmetic_types_int16: require
 #extension GL_EXT_shader_explicit_arithmetic_types_int64: require
 #extension GL_EXT_buffer_reference: require
+
 #ifdef REORDER_INVOCATIONS
 #extension GL_NV_shader_invocation_reorder: require
+// For hit shader invocation reordering hint
+#extension GL_EXT_buffer_reference: require
+#extension GL_EXT_buffer_reference_uvec2: require
+#endif
+
+#ifdef REQUIRE_CLOCK
+#extension GL_EXT_shader_explicit_arithmetic_types_int64: require
+#extension GL_ARB_shader_clock: require
 #endif
 
 #include "rp_main_payload.glsl"