Use external shaders instead of generating shader code from c++ code...

9 files changed, 103 insertions, 451 deletions

diff --git a/src/RenderBackend/OpenGL/CommonShader.cpp b/src/RenderBackend/OpenGL/CommonShader.cpp
deleted file mode 100644
index ea88f62..0000000
--- a/src/RenderBackend/OpenGL/CommonShader.cpp
+++ /dev/null
@@ -1,20 +0,0 @@
-#include "../../../include/RenderBackend/OpenGL/CommonShader.hpp"
-#include "../../../include/RenderBackend/OpenGL/opengl.hpp"
-
-using namespace std;
-
-namespace amalgine
-{
-    string getShaderCompileLog(u32 shaderId)
-    {
-        string result;
-        GLint shaderLogLength;
-        glGetShaderiv(shaderId, GL_INFO_LOG_LENGTH, &shaderLogLength);
-        if(shaderLogLength > 0)
-        {
-            result.resize(shaderLogLength);
-            glGetShaderInfoLog(shaderId, shaderLogLength, NULL, &result[0]);
-        }
-        return result;
-    }
-}
diff --git a/src/RenderBackend/OpenGL/CompiledShader.cpp b/src/RenderBackend/OpenGL/CompiledShader.cpp
deleted file mode 100644
index f4a1fec..0000000
--- a/src/RenderBackend/OpenGL/CompiledShader.cpp
+++ /dev/null
@@ -1,40 +0,0 @@
-#include "../../../include/RenderBackend/OpenGL/CompiledShader.hpp"
-#include "../../../include/RenderBackend/OpenGL/opengl.hpp"
-
-using namespace std;
-
-namespace amalgine
-{
-    CompiledVertexShader::CompiledVertexShader(u32 _shaderId) :
-        shaderId(_shaderId)
-    {
-        
-    }
-    
-    CompiledVertexShader::~CompiledVertexShader()
-    {
-        glDeleteShader(shaderId);
-    }
-    
-    u32 CompiledVertexShader::getShaderId() const
-    {
-        return shaderId;
-    }
-    
-    CompiledPixelShader::CompiledPixelShader(u32 _shaderId, unordered_map<string, i32> &&_pixelAttributes) :
-        shaderId(_shaderId),
-        pixelAttributes(_pixelAttributes)
-    {
-        
-    }
-    
-    CompiledPixelShader::~CompiledPixelShader()
-    {
-        glDeleteShader(shaderId);
-    }
-    
-    u32 CompiledPixelShader::getShaderId() const
-    {
-        return shaderId;
-    }
-}
diff --git a/src/RenderBackend/OpenGL/DeviceFrame.cpp b/src/RenderBackend/OpenGL/DeviceFrame.cpp
index e79dfa1..2132f83 100644
--- a/src/RenderBackend/OpenGL/DeviceFrame.cpp
+++ b/src/RenderBackend/OpenGL/DeviceFrame.cpp
@@ -1,6 +1,7 @@
 #include "../../../include/RenderBackend/OpenGL/DeviceFrame.hpp"
 #include "../../../include/RenderBackend/OpenGL/DeviceMemory.hpp"
 #include "../../../include/RenderBackend/OpenGL/opengl.hpp"
+#include "../../../include/RenderBackend/OpenGL/ShaderProgram.hpp"
 
 namespace amalgine
 {
@@ -26,13 +27,13 @@ namespace amalgine
         return deviceMemory;
     }
     
-    void DeviceFrame::draw()
-    {
-        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+    void DeviceFrame::draw(ShaderProgram *shader) {
+        shader->use();
+        //glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
         for(DeviceMemory *deviceMemory : buffers)
         {
             deviceMemory->draw();
         }
-        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+        //glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
     }
 }
diff --git a/src/RenderBackend/OpenGL/DeviceMemory.cpp b/src/RenderBackend/OpenGL/DeviceMemory.cpp
index 0dd3e89..2d40569 100644
--- a/src/RenderBackend/OpenGL/DeviceMemory.cpp
+++ b/src/RenderBackend/OpenGL/DeviceMemory.cpp
@@ -33,7 +33,7 @@ namespace amalgine
         }
     }
     
-    DeviceMemory::DeviceMemory() : primitiveType(0), numVertices(0)
+    DeviceMemory::DeviceMemory() : primitiveType(0), numVertices(0), type(DeviceMemoryType::NONE)
     {
         glGenBuffers(1, &vertexBufferObjectId);
     }
@@ -43,11 +43,6 @@ namespace amalgine
         glDeleteBuffers(1, &vertexBufferObjectId);
     }
     
-    void DeviceMemory::operator delete(void *data)
-    {
-        free(data);
-    }
-    
     void DeviceMemory::use() const
     {
         // TODO: Bind vao here?
@@ -68,12 +63,11 @@ namespace amalgine
         glBufferData(GL_ARRAY_BUFFER, triangles.getByteSize(), triangles.data, getOpenglStorageType(storageType));
         primitiveType = GL_TRIANGLES;
         numVertices = triangles.size * 3;
+        type = DeviceMemoryType::VEC2;
     }
     
     void DeviceMemory::draw()
     {
-        if(primitiveType == 0)
-            throw DeviceMemoryEmpty("Unable to draw buffer as no data has been copied to device memory");
         glDrawArrays(primitiveType, 0, numVertices);
     }
 }
diff --git a/src/RenderBackend/OpenGL/PixelShader.cpp b/src/RenderBackend/OpenGL/PixelShader.cpp
deleted file mode 100644
index e6006f2..0000000
--- a/src/RenderBackend/OpenGL/PixelShader.cpp
+++ /dev/null
@@ -1,47 +0,0 @@
-#include "../../../include/RenderBackend/OpenGL/PixelShader.hpp"
-#include "../../../include/RenderBackend/OpenGL/opengl.hpp"
-#include "../../../include/RenderBackend/OpenGL/CompiledShader.hpp"
-
-namespace amalgine
-{
-    PixelShader::PixelShader()
-    {
-        glGetIntegerv(GL_MAX_DRAW_BUFFERS, &maxAttribs);
-    }
-
-    void PixelShader::defineMain(PixelShaderMainFunc mainFunc)
-    {
-        if(mainFuncDefined)
-            throw ShaderFunctionAlreadyDefined("main");
-        
-        writeBody("void main() {\n");
-        mainFunc();
-        mainFuncDefined = true;
-        writeBody("}\n\n");
-    }
-    
-    Result<CompiledPixelShader*> PixelShader::compile()
-    {
-        if(!mainFuncDefined)
-            return Result<CompiledPixelShader*>::Err("main function not defined (defineMain not called)");
-
-        GLuint fragmentShaderId = glCreateShader(GL_FRAGMENT_SHADER);
-        std::string verterShaderSource = build();
-        const char *verterShaderSourcePtr = verterShaderSource.c_str();
-        printf("Vertex shader:\n%s\n", verterShaderSourcePtr);
-        glShaderSource(fragmentShaderId, 1, &verterShaderSourcePtr, NULL);
-        glCompileShader(fragmentShaderId);
-        
-        GLint status;
-        glGetShaderiv(fragmentShaderId, GL_COMPILE_STATUS, &status);
-        std::string compileLog = getShaderCompileLog((u32)fragmentShaderId);
-        if(status == GL_TRUE)
-        {
-            if(!compileLog.empty())
-                printf("Pixel shader compile log:\n%s", compileLog.c_str());
-            return Result<CompiledPixelShader*>::Ok(new CompiledPixelShader(fragmentShaderId, move(inputAttributes)));
-        }
-        else
-            return Result<CompiledPixelShader*>::Err(compileLog);
-    }
-}
diff --git a/src/RenderBackend/OpenGL/Shader.cpp b/src/RenderBackend/OpenGL/Shader.cpp
index fad1702..3b6563f 100644
--- a/src/RenderBackend/OpenGL/Shader.cpp
+++ b/src/RenderBackend/OpenGL/Shader.cpp
@@ -1,169 +1,55 @@
 #include "../../../include/RenderBackend/OpenGL/Shader.hpp"
 #include "../../../include/RenderBackend/OpenGL/opengl.hpp"
-#include "../../../include/RenderBackend/OpenGL/CompiledShader.hpp"
-#include <cassert>
-
-using namespace std;
 
 namespace amalgine {
-    ShaderTooManyAttributes::ShaderTooManyAttributes(i32 maxAttributes) : 
-        runtime_error(string("Attempting to define more than ") + to_string(maxAttributes) + " attributes")
-    {
-        
-    }
-    
-    ShaderAttributeAlreadyDefined::ShaderAttributeAlreadyDefined(const std::string &attributeName) : 
-        runtime_error(string("An attribute with the name ") + attributeName + " has already been defined")
-    {
-        
-    }
-    
-    ShaderInvalidAttributeName::ShaderInvalidAttributeName(const std::string &attributeName) : 
-        runtime_error(string("Attribute name ") + attributeName + " is invalid")
-    {
-        
-    }
-    
-    ShaderFunctionAlreadyDefined::ShaderFunctionAlreadyDefined(const std::string &funcName) : 
-        runtime_error(string("Shader function already defined: ") + funcName)
-    {
-        
-    }
-    
-    Shader::Shader() : inputLocationCounter(0), outputLocationCounter(0), mainFuncDefined(false)
-    {
-        writeHeader("#version 330 core\n\n");
-    }
-    
-    const string& Shader::getOutputAttributeName(i32 attributeIndex)
-    {
-        assert(attributeIndex < (i32)outputAttributeNames.size());
-        return outputAttributeNames[attributeIndex].name;
+    static GLuint to_opengl_shader_type(Shader::Type type) {
+        switch(type) {
+            case Shader::Type::VERTEX:
+                return GL_VERTEX_SHADER;
+            case Shader::Type::PIXEL:
+                return GL_FRAGMENT_SHADER;
+        }
+        assert(false);
     }
 
-    const string& Shader::getInputAttributeName(i32 attributeIndex) const
-    {
-        assert(attributeIndex < (i32)inputAttributeNames.size());
-        return inputAttributeNames[attributeIndex].name;
-    }
-    
-    AttributeType Shader::getInputAttributeType(i32 attributeIndex) const
-    {
-        assert(attributeIndex < (i32)inputAttributeNames.size());
-        return getAttributeTypeByName(inputAttributeNames[attributeIndex].typeName);
-    }
-    
-    ShaderOutputVec4 Shader::defineOutputVec4(const std::string &name)
-    {
-        i32 attributeIndex = defineOutputVariable(name, "vec4");
-        return ShaderOutputVec4(this, attributeIndex);
-    }
-    
-    // TODO: Generate warning if global variable is defined but not assigned to?
-    ShaderGlobalVec3 Shader::defineGlobalVec3(const std::string &name)
-    {
-        if(!isShaderVariableNameValid(name.c_str()))
-            throw ShaderInvalidAttributeName(name);
-        
-        if(uniforms.find(name) != uniforms.end())
-            throw ShaderAttributeAlreadyDefined(name);
-        
-        writeHeader("uniform vec3 ");
-        writeHeader(name);
-        writeHeader(";\n");
-        
-        ShaderGlobalVec3 globalVec(name);
-        uniforms[name] = globalVec.getVecObject();
-        return ShaderGlobalVec3(globalVec);
-    }
-    
-    i32 Shader::defineOutputVariable(const string &variableName, const char *typeName)
-    {
-        if(!isShaderVariableNameValid(variableName.c_str()))
-            throw ShaderInvalidAttributeName(variableName);
-        
-        if(outputLocationCounter + 1 > maxAttribs)
-            throw ShaderTooManyAttributes(maxAttribs);
-        
-        if(outputAttributes.find(variableName) != outputAttributes.end())
-            throw ShaderAttributeAlreadyDefined(variableName);
-        
-        i32 attributeIndex = outputLocationCounter;
-        outputAttributes[variableName] = outputLocationCounter;
-        writeHeader("out ");
-        writeHeader(typeName);
-        writeHeader(" ");
-        writeHeader(variableName);
-        writeHeader(";\n");
-        
-        ShaderAttribute shaderAttribute;
-        shaderAttribute.name = variableName;
-        shaderAttribute.typeName = typeName;
-        outputAttributeNames.push_back(shaderAttribute);
-        ++outputLocationCounter;
-        return attributeIndex;
-    }
-
-    ShaderInputVec2 Shader::defineInputVec2(const std::string &name)
-    {
-        i32 attributeIndex = defineInputVariable(name, "vec2");
-        return ShaderInputVec2(this, attributeIndex);
-    }
-
-    i32 Shader::defineInputVariable(const string &variableName, const char *typeName)
-    {
-        if(!isShaderVariableNameValid(variableName.c_str()))
-            throw ShaderInvalidAttributeName(variableName);
-        
-        if(inputLocationCounter + 1 > maxAttribs)
-            throw ShaderTooManyAttributes(maxAttribs);
-        
-        if(inputAttributes.find(variableName) != inputAttributes.end())
-            throw ShaderAttributeAlreadyDefined(variableName);
-        
-        i32 attributeIndex = inputLocationCounter;
-        inputAttributes[variableName] = inputLocationCounter;
-        ShaderAttribute shaderAttribute;
-        shaderAttribute.name = variableName;
-        shaderAttribute.typeName = typeName;
-        inputAttributeNames.push_back(shaderAttribute);
-        
-        writeHeader("layout(location = ");
-        writeHeader(to_string(inputLocationCounter));
-        ++inputLocationCounter;
-        writeHeader(") in ");
-        writeHeader(typeName);
-        writeHeader(" ");
-        writeHeader(variableName);
-        writeHeader(";\n");
-        return attributeIndex;
-    }
-    
-    void Shader::assign(const ShaderOutputVec4 &lhsVariable, const ShaderVec4 &rhsVariable)
-    {
-        writeBody(lhsVariable.getName());
-        writeBody(" = ");
-        writeBody(rhsVariable.getOutput());
-        writeBody(";\n");
-    }
-    
-    string Shader::build() const
+    static std::string get_shader_compile_log(GLuint shaderId)
     {
         std::string result;
-        result.reserve(header.size() + 2 + body.size());
-        result += header;
-        result += "\n";
-        result += body;
+        GLint shaderLogLength;
+        glGetShaderiv(shaderId, GL_INFO_LOG_LENGTH, &shaderLogLength);
+        if(shaderLogLength > 0) {
+            result.resize(shaderLogLength);
+            glGetShaderInfoLog(shaderId, shaderLogLength, NULL, &result[0]);
+        }
         return result;
     }
-    
-    void Shader::writeHeader(const string &code)
-    {
-        header += code;
+
+    Shader::Shader(u32 shader_id) : id(shader_id) {
+        
     }
-    
-    void Shader::writeBody(const string &code)
-    {
-        body += code;
+
+    Shader::~Shader() {
+        glDeleteShader(id);
+    }
+    
+    // static
+    Result<std::unique_ptr<Shader>> Shader::compile(Type type, const char *str, int size) {
+        GLuint shader_id = glCreateShader(to_opengl_shader_type(type));
+        GLint shader_lengths[1] = { size };
+        glShaderSource(shader_id, 1, &str, shader_lengths);
+        glCompileShader(shader_id);
+        
+        GLint status;
+        glGetShaderiv(shader_id, GL_COMPILE_STATUS, &status);
+        std::string compileLog = get_shader_compile_log(shader_id);
+        if(status == GL_TRUE) {
+            if(!compileLog.empty())
+                fprintf(stderr, "Shader compile log:\n%s", compileLog.c_str());
+            std::unique_ptr<Shader> shader;
+            shader.reset(new Shader(shader_id));
+            return Result<std::unique_ptr<Shader>>::Ok(std::move(shader));
+        }
+        else
+            return Result<std::unique_ptr<Shader>>::Err(compileLog);
     }
 }
diff --git a/src/RenderBackend/OpenGL/ShaderProgram.cpp b/src/RenderBackend/OpenGL/ShaderProgram.cpp
index aceda3b..e613668 100644
--- a/src/RenderBackend/OpenGL/ShaderProgram.cpp
+++ b/src/RenderBackend/OpenGL/ShaderProgram.cpp
@@ -1,56 +1,34 @@
 #include "../../../include/RenderBackend/OpenGL/ShaderProgram.hpp"
+
+#include "../../../include/RenderBackend/OpenGL/Shader.hpp"
 #include "../../../include/RenderBackend/OpenGL/opengl.hpp"
-#include "../../../include/RenderBackend/OpenGL/CompiledShader.hpp"
 
 using namespace std;
 
-namespace amalgine
-{
-    ShaderProgramUsedBeforeBuilt::ShaderProgramUsedBeforeBuilt() : 
-        runtime_error("Shader program was used before it was built")
-    {
+namespace amalgine {
+    ShaderProgram::ShaderProgram(u32 shader_program_id) : program_id(shader_program_id) {
         
     }
     
-    ShaderProgramNonExistingGlobalVariable::ShaderProgramNonExistingGlobalVariable(const char *variableName) : 
-        runtime_error(string("There is no shader global variable with the name '") + variableName + "'")
-    {
-        
-    }
-    
-    ShaderProgram::ShaderProgram() : built(false)
-    {
-        shaderProgramId = glCreateProgram();
-    }
-    
     ShaderProgram::~ShaderProgram()
     {
         GLint numAttachedShaders;
-        glGetProgramiv(shaderProgramId, GL_ATTACHED_SHADERS, &numAttachedShaders);
+        glGetProgramiv(program_id, GL_ATTACHED_SHADERS, &numAttachedShaders);
         
         GLuint *attachedShaders = new GLuint[numAttachedShaders];
-        glGetAttachedShaders(shaderProgramId, numAttachedShaders, nullptr, attachedShaders);
+        glGetAttachedShaders(program_id, numAttachedShaders, nullptr, attachedShaders);
         
         for(int i = 0; i < numAttachedShaders; ++i)
         {
             GLuint attachedShaderId = attachedShaders[i];
-            glDetachShader(shaderProgramId, attachedShaderId);
+            glDetachShader(program_id, attachedShaderId);
         }
         
-        glDeleteProgram(shaderProgramId);
-    }
-    
-    // TODO: Before adding shader to program, check if it has already been added
-    
-    bool ShaderProgram::setVertexShader(CompiledVertexShader *vertexShader)
-    {
-        if(!vertexShader) return false;
-        
-        // TODO: Do not allow adding shader if the program has already been built
-        glAttachShader(shaderProgramId, vertexShader->getShaderId());
-        return true;
+        glDeleteProgram(program_id);
+        delete []attachedShaders;
     }
     
+    #if 0
     bool ShaderProgram::setPixelShader(CompiledPixelShader *pixelShader)
     {
         if(!pixelShader) return false;
@@ -68,41 +46,55 @@ namespace amalgine
         
         return true;
     }
+    #endif
     
-    Result<bool> ShaderProgram::build()
-    {
-        if(built)
-            return Result<bool>::Err("Shader program already built");
+    // static
+    Result<std::unique_ptr<ShaderProgram>> ShaderProgram::build(const std::vector<Shader*> &shaders) {
+        u32 shader_program_id = glCreateProgram();
+        if(shader_program_id == 0)
+            return Result<std::unique_ptr<ShaderProgram>>::Err("Failed to create shader program");
         
-        glLinkProgram(shaderProgramId);
-        built = true;
-        return Result<bool>::Ok(true);
-    }
-    
-    void ShaderProgram::use()
-    {
-        if(built)
-        {
-            glUseProgram(shaderProgramId);
-        }
-        else
-        {
-            throw ShaderProgramUsedBeforeBuilt();
+        for(Shader *shader : shaders) {
+            glAttachShader(shader_program_id, shader->id);
         }
+        
+        glLinkProgram(shader_program_id);
+        std::unique_ptr<ShaderProgram> shader_program;
+        shader_program.reset(new ShaderProgram(shader_program_id));
+        return Result<std::unique_ptr<ShaderProgram>>::Ok(std::move(shader_program));
     }
-    
-    ShaderProgramGlobalVec3 ShaderProgram::getGlobalVec3(const char *name)
-    {
-        if(built)
-        {
-            GLint uniformId = glGetUniformLocation(shaderProgramId, name);
-            if(uniformId == -1)
-                throw ShaderProgramNonExistingGlobalVariable(name);
-            return ShaderProgramGlobalVec3(this, uniformId);
+
+    int ShaderProgram::set_uniform(const char *name, const vec3f &value) {
+        GLint uniformId = glGetUniformLocation(program_id, name);
+        if(uniformId == -1)
+            return -1;
+        use();
+        glUniform3f(uniformId, value.x, value.y, value.z);
+        return 0;
+    }
+
+    int ShaderProgram::set_vertex_input(const char *name, const DeviceMemory &data) {
+        GLint attrib_location = glGetAttribLocation(program_id, name);
+        if(attrib_location == -1) {
+            fprintf(stderr, "No such attribute in shader: %s\n", name);
+            return -1;
         }
-        else
-        {
-            throw ShaderProgramUsedBeforeBuilt();
+
+        data.use();
+        switch(data.get_type()) {
+            case DeviceMemoryType::NONE:
+                return -1;
+            case DeviceMemoryType::VEC2: {
+                glVertexAttribPointer(attrib_location, 2, GL_FLOAT, GL_FALSE, 0, 0);
+                break;
+            }
+            case DeviceMemoryType::VEC3: assert(false); return -1;
         }
+        glEnableVertexAttribArray(attrib_location);
+        return 0;
+    }
+
+    void ShaderProgram::use() {
+        glUseProgram(program_id);
     }
 }
diff --git a/src/RenderBackend/OpenGL/ShaderVec.cpp b/src/RenderBackend/OpenGL/ShaderVec.cpp
deleted file mode 100644
index 8897b84..0000000
--- a/src/RenderBackend/OpenGL/ShaderVec.cpp
+++ /dev/null
@@ -1,69 +0,0 @@
-#include "../../../include/RenderBackend/OpenGL/ShaderVec.hpp"
-#include "../../../include/RenderBackend/OpenGL/Shader.hpp"
-#include "../../../include/RenderBackend/OpenGL/ShaderProgram.hpp"
-#include "../../../include/RenderBackend/OpenGL/opengl.hpp"
-#include <cstring>
-#include <cassert>
-
-using namespace std;
-
-namespace amalgine
-{    
-    AttributeType getAttributeTypeByName(const char *attributeName)
-    {
-        if(strncmp(attributeName, "vec2", 4) == 0)
-        {
-            return AttributeType::VEC2;
-        }
-        else if(strncmp(attributeName, "vec3", 4) == 0)
-        {
-            return AttributeType::VEC3;
-        }
-        else if(strncmp(attributeName, "vec4", 4) == 0)
-        {
-            return AttributeType::VEC4;
-        }
-        
-        assert(false);
-        return AttributeType::NONE;
-    }
-    
-    void ShaderProgramGlobalVec3::set(f32 x, f32 y, f32 z)
-    {
-        shaderProgram->use();
-        glUniform3f(uniformId, x, y, z);
-    }
-    
-    const string& ShaderInputVec2::getName() const
-    {
-        return shader->getInputAttributeName(attributeIndex);
-    }
-    
-    void ShaderInputVec2::setData(const DeviceMemory &data)
-    {
-        data.use();
-        AttributeType attributeType = shader->getInputAttributeType(attributeIndex);
-        switch(attributeType)
-        {
-            case AttributeType::VEC2:
-            {
-                glVertexAttribPointer(attributeIndex, 2, GL_FLOAT, GL_FALSE, 0, 0);
-                break;
-            }
-            default:
-                assert(false);
-                break;
-        }
-        glEnableVertexAttribArray(attributeIndex);
-    }
-    
-    const string& ShaderOutputVec4::getName() const
-    {
-        return shader->getOutputAttributeName(attributeIndex);
-    }
-    
-    void ShaderOutputVec4::operator=(const ShaderVec4 &shaderVec4)
-    {
-        shader->assign(*this, shaderVec4);
-    }
-}
diff --git a/src/RenderBackend/OpenGL/VertexShader.cpp b/src/RenderBackend/OpenGL/VertexShader.cpp
deleted file mode 100644
index 19705b6..0000000
--- a/src/RenderBackend/OpenGL/VertexShader.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-#include "../../../include/RenderBackend/OpenGL/VertexShader.hpp"
-#include "../../../include/RenderBackend/OpenGL/opengl.hpp"
-#include "../../../include/RenderBackend/OpenGL/CompiledShader.hpp"
-
-namespace amalgine {
-    VertexShader::VertexShader()
-    {
-        glGetIntegerv(GL_MAX_VERTEX_ATTRIBS, &maxAttribs);
-    }
-
-    void VertexShader::defineMain(VertexShaderMainFunc mainFunc)
-    {
-        if(mainFuncDefined)
-            throw ShaderFunctionAlreadyDefined("main");
-        
-        writeBody("void main() {\n");
-        ShaderVec4 glPosition = mainFunc();
-        mainFuncDefined = true;
-        writeBody("gl_Position = ");
-        writeBody(glPosition.getOutput());
-        writeBody(";\n}\n\n");
-    }
-
-    Result<CompiledVertexShader*> VertexShader::compile()
-    {
-        GLuint vertexShaderId = glCreateShader(GL_VERTEX_SHADER);
-        std::string verterShaderSource = build();
-        const char *verterShaderSourcePtr = verterShaderSource.c_str();
-        printf("Vertex shader:\n%s\n", verterShaderSourcePtr);
-        glShaderSource(vertexShaderId, 1, &verterShaderSourcePtr, NULL);
-        glCompileShader(vertexShaderId);
-        
-        GLint status;
-        glGetShaderiv(vertexShaderId, GL_COMPILE_STATUS, &status);
-        std::string compileLog = getShaderCompileLog((u32)vertexShaderId);
-        if(status == GL_TRUE)
-        {
-            if(!compileLog.empty())
-                printf("Vertex shader compile log:\n%s", compileLog.c_str());
-            return Result<CompiledVertexShader*>::Ok(new CompiledVertexShader(vertexShaderId));
-        }
-        else
-            return Result<CompiledVertexShader*>::Err(compileLog);
-    }
-}