urho3d/Engine/Graphics/OpenGL/OGLShaderVariation.cpp

//
// Urho3D Engine
// Copyright (c) 2008-2011 Lasse Öörni
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#include "Precompiled.h"
#include "Graphics.h"
#include "GraphicsImpl.h"
#include "Shader.h"
#include "ShaderProgram.h"
#include "ShaderVariation.h"

#include <GLee.h>

#include "DebugNew.h"

ShaderVariation::ShaderVariation(Shader* shader, ShaderType type) :
    GPUObject(shader->GetSubsystem<Graphics>()),
    shader_(shader),
    shaderType_(type),
    compiled_(false)
{
}

ShaderVariation::~ShaderVariation()
{
    Release();
}

void ShaderVariation::Release()
{
    if (object_)
    {
        if (!graphics_)
            return;
        
        if (shaderType_ == VS)
        {
            if (graphics_->GetPixelShader() == this)
                graphics_->SetShaders(0, 0);
        }
        else
        {
            if (graphics_->GetVertexShader() == this)
                graphics_->SetShaders(0, 0);
        }
        
        // Release the linked shader program if exists
        if (shaderProgram_)
        {
            shaderProgram_->Release();
            shaderProgram_.Reset();
            graphics_->CleanupShaderPrograms();
        }
        
        glDeleteShader(object_);
        object_ = 0;
        compiled_ = false;
    }
}

bool ShaderVariation::Create()
{
    Release();
    
    if (!shader_)
        return false;
    
    object_ = glCreateShader((shaderType_ == VS) ? GL_VERTEX_SHADER : GL_FRAGMENT_SHADER);
    if (!object_)
    {
        compilerOutput_ = "Could not create shader object";
        return false;
    }
    
    // Prepend the defines to the shader code
    String shaderCode;
    for (unsigned i = 0; i < defines_.Size(); ++i)
        shaderCode += "#define " + defines_[i] + "\n";
    shaderCode += shader_->GetShaderCode();
    
    const char* shaderCStr = shaderCode.CString();
    glShaderSource(object_, 1, &shaderCStr, 0);
    glCompileShader(object_);
    
    int compiled, length;
    glGetShaderiv(object_, GL_COMPILE_STATUS, &compiled);
    compiled_ = compiled != 0;
    if (!compiled_)
    {
        glGetShaderiv(object_, GL_INFO_LOG_LENGTH, &length);
        compilerOutput_.Resize(length);
        glGetShaderInfoLog(object_, length, &length, &compilerOutput_[0]);
    }
    else
        compilerOutput_.Clear();
    
    return compiled_;
}

void ShaderVariation::SetName(const String& name)
{
    name_ = name;
}

void ShaderVariation::SetDefines(const Vector<String>& defines)
{
    defines_ = defines;
}

Shader* ShaderVariation::GetShader() const
{
    return shader_;
}