/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * 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 ShaderProgram_h
#define ShaderProgram_h

#if USE(ACCELERATED_COMPOSITING)

#include "FloatRect.h"
#include "IntRect.h"
#include "SkRect.h"
#include "TransformationMatrix.h"
#include <GLES2/gl2.h>

namespace WebCore {

class ShaderProgram {
 public:
    ShaderProgram();
    void init();
    int projectionMatrix() { return m_hProjectionMatrix; }
    int alpha() { return m_hAlpha; }
    int textureSampler() { return m_hTexSampler; }
    int program() { return m_program; }

    // Drawing
    void setViewport(SkRect& viewport);
    void drawQuad(SkRect& geometry, int textureId, float opacity);
    void drawLayerQuad(const TransformationMatrix& drawMatrix,
                     SkRect& geometry, int textureId, float opacity,
                     bool forceBlending = false);
    void drawVideoLayerQuad(const TransformationMatrix& drawMatrix,
                     float* textureMatrix, SkRect& geometry, int textureId);
    void setViewRect(const IntRect& viewRect);
    FloatRect clipRectInScreenCoord(const TransformationMatrix& drawMatrix,
                                    const IntSize& size);
    void clip(const FloatRect& rect);
    IntRect clippedRectWithViewport(const IntRect& rect, int margin = 0);

    void resetBlending();

 private:
    GLuint loadShader(GLenum shaderType, const char* pSource);
    GLuint createProgram(const char* vertexSource, const char* fragmentSource);
    void setProjectionMatrix(SkRect& geometry);

    void setBlendingState(bool enableBlending);

    bool m_blendingEnabled;

    int m_program;
    int m_videoProgram;

    TransformationMatrix m_projectionMatrix;
    GLuint m_textureBuffer[1];

    TransformationMatrix m_clippingMatrix;
    SkRect m_viewport;
    IntRect m_viewRect;
    FloatRect m_clipRect;

    // uniforms
    int m_hProjectionMatrix;
    int m_hAlpha;
    int m_hTexSampler;
    int m_hVideoProjectionMatrix;
    int m_hVideoTextureMatrix;
    int m_hVideoTexSampler;

    // attribs
    GLint m_hPosition;
    GLint m_hVideoPosition;
};

} // namespace WebCore

#endif // USE(ACCELERATED_COMPOSITING)
#endif // ShaderProgram_h