InstancedShaderBase.h

/*
 * Copyright (C) 2014 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef INSTANCEDSHADERBASE_H
#define INSTANCEDSHADERBASE_H

#include "InstancedShader.h"
#include "RendererCommon.h"
#include "ShaderBase.h"

template<typename TShaderImpl>
class InstancedShaderBase : public InstancedShader {
public:
    InstancedShaderBase() : InstancedShader(getSharedShader()) { }

    static const ShaderPtr& getSharedShader() {
        // To avoid static shared pointers and initialization issues, make this
        // a raw pointer to a shared pointer.
        // Note: It never gets deleted, similarly with our other singletons.
        static ShaderPtr* sSharedShader = nullptr;
        if (!sSharedShader) {
            sSharedShader = new ShaderPtr(TShaderImpl::createSharedShader());
        }
        return *sSharedShader;
    }

protected:
    static ShaderPtr createSharedShader() {
        std::string vertexShaderCode(TShaderImpl::getVertexShaderCode());
        std::string fragmentShaderCode(TShaderImpl::getFragmentShaderCode());
        AttributeSetPtr attributeSet(TShaderImpl::getAttributeSet());
        std::vector<std::string> uniformNames(TShaderImpl::getUniformNames());
        ShaderPtr shader = ShaderPtr(new ShaderBase(vertexShaderCode, fragmentShaderCode,
                attributeSet, uniformNames));
        shader->compile();
        return shader;
    }
};

#endif // INSTANCEDSHADERBASE_H