Add a binary cache for compiled shaders using glProgramBinary (#216)

* Add a binary cache for compiled shaders using glProgramBinary

* Add additional sanity checking to shader binary save and load, hook up cache clear and menu option

* Fix default init of shader cache data struct and clear gl errors before glGetError calls

---------

Co-authored-by: RunitaiLinden <davep@lindenlab.com>

1 files changed, 18 insertions, 3 deletions

diff --git a/indra/llrender/llshadermgr.h b/indra/llrender/llshadermgr.h
index ec3455952b..4a2241a9d6 100644
--- a/indra/llrender/llshadermgr.h
+++ b/indra/llrender/llshadermgr.h
@@ -295,7 +295,7 @@ public:
     void dumpShaderSource(U32 shader_code_count, GLchar** shader_code_text);
 	BOOL	linkProgramObject(GLuint obj, BOOL suppress_errors = FALSE);
 	BOOL	validateProgramObject(GLuint obj);
-	GLuint loadShaderFile(const std::string& filename, S32 & shader_level, GLenum type, std::unordered_map<std::string, std::string>* defines = NULL, S32 texture_index_channels = -1);
+	GLuint loadShaderFile(const std::string& filename, S32 & shader_level, GLenum type, std::map<std::string, std::string>* defines = NULL, S32 texture_index_channels = -1);
 
 	// Implemented in the application to actually point to the shader directory.
 	virtual std::string getShaderDirPrefix(void) = 0; // Pure Virtual
@@ -303,6 +303,13 @@ public:
 	// Implemented in the application to actually update out of date uniforms for a particular shader
 	virtual void updateShaderUniforms(LLGLSLShader * shader) = 0; // Pure Virtual
 
+    void initShaderCache(bool enabled, const LLUUID& old_cache_version, const LLUUID& current_cache_version);
+    void clearShaderCache();
+    void persistShaderCacheMetadata();
+
+    bool loadCachedProgramBinary(LLGLSLShader* shader);
+    bool saveCachedProgramBinary(LLGLSLShader* shader);
+
 public:
 	// Map of shader names to compiled
     std::map<std::string, GLuint> mVertexShaderObjects;
@@ -313,8 +320,16 @@ public:
 
 	std::vector<std::string> mReservedUniforms;
 
-	//preprocessor definitions (name/value)
-	std::map<std::string, std::string> mDefinitions;
+    struct ProgramBinaryData
+    {
+        GLsizei mBinaryLength = 0;
+        GLenum mBinaryFormat = 0;
+        F32 mLastUsedTime = 0.0;
+    };
+    std::map<LLUUID, ProgramBinaryData> mShaderBinaryCache;
+    bool mShaderCacheInitialized = false;
+    bool mShaderCacheEnabled = false;
+    std::string mShaderCacheDir;
 
 protected: