From ef1bca542460c84bbf571d55e0fa0defd2bdddef Mon Sep 17 00:00:00 2001
From: vlj <vljn@ovi.com>
Date: Sun, 13 Jul 2014 00:11:35 +0200
Subject: [PATCH] Try to factorize shader using variadic templates.

---
 src/graphics/shaders.cpp | 28 ++++++++++++----------------
 src/graphics/shaders.hpp | 39 ++++++++++++++++++++++++++++++++++++---
 2 files changed, 48 insertions(+), 19 deletions(-)

diff --git a/src/graphics/shaders.cpp b/src/graphics/shaders.cpp
index de08cb62e..a8ab85918 100644
--- a/src/graphics/shaders.cpp
+++ b/src/graphics/shaders.cpp
@@ -394,7 +394,7 @@ void Shaders::check(const int num) const
     }
 }
 
-static void bypassUBO(GLint Program)
+void bypassUBO(GLuint Program)
 {
     GLint VM = glGetUniformLocation(Program, "ViewMatrix");
     glUniformMatrix4fv(VM, 1, GL_FALSE, irr_driver->getViewMatrix().pointer());
@@ -455,13 +455,20 @@ AssignTextureUnit(GLuint Program, const std::vector<std::pair<GLuint, const char
     glUseProgram(0);
 }
 
+static void
+AssignUniforms(GLuint Program, std::vector<GLuint> &uniforms, const std::vector<const char*> &name)
+{
+    for (unsigned i = 0; i < name.size(); i++)
+    {
+        uniforms.push_back(glGetUniformLocation(Program, name[i]));
+    }
+}
+
 namespace MeshShader
 {
 
     // Solid Normal and depth pass shaders
     GLuint ObjectPass1Shader::Program;
-    GLuint ObjectPass1Shader::uniform_MM;
-    GLuint ObjectPass1Shader::uniform_IMM;
     GLuint ObjectPass1Shader::TU_tex;
 
     void ObjectPass1Shader::init()
@@ -470,8 +477,7 @@ namespace MeshShader
             GL_VERTEX_SHADER, file_manager->getAsset("shaders/object_pass.vert").c_str(),
             GL_FRAGMENT_SHADER, file_manager->getAsset("shaders/utils/encode_normal.frag").c_str(),
             GL_FRAGMENT_SHADER, file_manager->getAsset("shaders/object_pass1.frag").c_str());
-        uniform_MM = glGetUniformLocation(Program, "ModelMatrix");
-        uniform_IMM = glGetUniformLocation(Program, "InverseModelMatrix");
+        AssignUniforms(Program, uniforms, {"ModelMatrix", "InverseModelMatrix"});
         if (!UserConfigParams::m_ubo_disabled)
         {
             GLuint uniform_ViewProjectionMatrixesUBO = glGetUniformBlockIndex(Program, "MatrixesData");
@@ -481,14 +487,6 @@ namespace MeshShader
         AssignTextureUnit(Program, { { TU_tex, "tex" } });
     }
 
-    void ObjectPass1Shader::setUniforms(const core::matrix4 &ModelMatrix, const core::matrix4 &InverseModelMatrix)
-    {
-        if (UserConfigParams::m_ubo_disabled)
-            bypassUBO(Program);
-        glUniformMatrix4fv(uniform_MM, 1, GL_FALSE, ModelMatrix.pointer());
-        glUniformMatrix4fv(uniform_IMM, 1, GL_FALSE, InverseModelMatrix.pointer());
-    }
-
     GLuint ObjectRefPass1Shader::Program;
     GLuint ObjectRefPass1Shader::uniform_MM;
     GLuint ObjectRefPass1Shader::uniform_IMM;
@@ -517,9 +515,7 @@ namespace MeshShader
     {
         if (UserConfigParams::m_ubo_disabled)
             bypassUBO(Program);
-        glUniformMatrix4fv(uniform_MM, 1, GL_FALSE, ModelMatrix.pointer());
-        glUniformMatrix4fv(uniform_TM, 1, GL_FALSE, TextureMatrix.pointer());
-        glUniformMatrix4fv(uniform_IMM, 1, GL_FALSE, InverseModelMatrix.pointer());
+        setUniformsHelper({ uniform_MM, uniform_TM, uniform_IMM }, ModelMatrix, InverseModelMatrix, TextureMatrix);
     }
 
     GLuint GrassPass1Shader::Program;
diff --git a/src/graphics/shaders.hpp b/src/graphics/shaders.hpp
index cc71800a0..f7d967bae 100644
--- a/src/graphics/shaders.hpp
+++ b/src/graphics/shaders.hpp
@@ -47,17 +47,50 @@ public:
 };
 }
 
+template<unsigned N>
+void setUniformsHelper(const std::vector<GLuint> &uniforms)
+{
+}
+
+template<unsigned N = 0, typename... Args>
+void setUniformsHelper(const std::vector<GLuint> &uniforms, const core::matrix4 &mat, Args... arg)
+{
+#ifndef GL_FALSE
+#define GL_FALSE 0
+#endif
+    glUniformMatrix4fv(uniforms[N], 1, GL_FALSE, mat.pointer());
+    ::template setUniformsHelper<N + 1>(uniforms, arg...);
+}
+
+void bypassUBO(GLuint Program);
+
+template<typename... Args>
+class ShaderHelper
+{
+protected:
+    static std::vector<GLuint> uniforms;
+    static GLuint Program;
+public:
+    static void setUniforms(const Args & ... args)
+    {
+        if (UserConfigParams::m_ubo_disabled)
+            bypassUBO(Program);
+        ::template setUniformsHelper(uniforms, args...);
+    }
+};
+
+template<typename... Args> std::vector<GLuint> ShaderHelper<Args...>::uniforms;
+template<typename... Args> GLuint ShaderHelper<Args...>::Program;
+
 namespace MeshShader
 {
-class ObjectPass1Shader
+class ObjectPass1Shader : public ShaderHelper<core::matrix4, core::matrix4>
 {
 public:
     static GLuint Program;
-    static GLuint uniform_MM, uniform_IMM;
     static GLuint TU_tex;
 
     static void init();
-    static void setUniforms(const core::matrix4 &ModelMatrix, const core::matrix4 &InverseModelMatrix);
 };
 
 class ObjectRefPass1Shader