/*
 * 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 ANDROID_UI_CACHES_H
#define ANDROID_UI_CACHES_H

#ifndef LOG_TAG
    #define LOG_TAG "OpenGLRenderer"
#endif

#include <utils/Singleton.h>

#include "FontRenderer.h"
#include "GammaFontRenderer.h"
#include "TextureCache.h"
#include "LayerCache.h"
#include "GradientCache.h"
#include "PatchCache.h"
#include "ProgramCache.h"
#include "PathCache.h"
#include "TextDropShadowCache.h"
#include "FboCache.h"
#include "Line.h"

namespace android {
namespace uirenderer {

///////////////////////////////////////////////////////////////////////////////
// Globals
///////////////////////////////////////////////////////////////////////////////

#define REQUIRED_TEXTURE_UNITS_COUNT 3

// Generates simple and textured vertices
#define FV(x, y, u, v) { { x, y }, { u, v } }

// This array is never used directly but used as a memcpy source in the
// OpenGLRenderer constructor
static const TextureVertex gMeshVertices[] = {
        FV(0.0f, 0.0f, 0.0f, 0.0f),
        FV(1.0f, 0.0f, 1.0f, 0.0f),
        FV(0.0f, 1.0f, 0.0f, 1.0f),
        FV(1.0f, 1.0f, 1.0f, 1.0f)
};
static const GLsizei gMeshStride = sizeof(TextureVertex);
static const GLsizei gMeshTextureOffset = 2 * sizeof(float);
static const GLsizei gMeshCount = 4;

///////////////////////////////////////////////////////////////////////////////
// Debug
///////////////////////////////////////////////////////////////////////////////

struct CacheLogger {
    CacheLogger() {
        LOGD("Creating caches");
    }
}; // struct CacheLogger

///////////////////////////////////////////////////////////////////////////////
// Caches
///////////////////////////////////////////////////////////////////////////////

class Caches: public Singleton<Caches> {
    Caches(): Singleton<Caches>(), blend(false), lastSrcMode(GL_ZERO),
            lastDstMode(GL_ZERO), currentProgram(NULL) {
        GLint maxTextureUnits;
        glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &maxTextureUnits);
        if (maxTextureUnits < REQUIRED_TEXTURE_UNITS_COUNT) {
            LOGW("At least %d texture units are required!", REQUIRED_TEXTURE_UNITS_COUNT);
        }

        glGenBuffers(1, &meshBuffer);
        glBindBuffer(GL_ARRAY_BUFFER, meshBuffer);
        glBufferData(GL_ARRAY_BUFFER, sizeof(gMeshVertices), gMeshVertices, GL_STATIC_DRAW);

        currentBuffer = meshBuffer;
    }

    friend class Singleton<Caches>;

    CacheLogger logger;

public:
    /**
     * Binds the VBO used to render simple textured quads.
     */
    inline void bindMeshBuffer() {
        bindMeshBuffer(meshBuffer);
    }

    /**
     * Binds the specified VBO.
     */
    inline void bindMeshBuffer(const GLuint buffer) {
        if (currentBuffer != buffer) {
            glBindBuffer(GL_ARRAY_BUFFER, buffer);
            currentBuffer = buffer;
        }
    }

    /**
     * Unbinds the VBO used to render simple textured quads.
     */
    inline void unbindMeshBuffer() {
        if (currentBuffer) {
            glBindBuffer(GL_ARRAY_BUFFER, 0);
            currentBuffer = 0;
        }
    }

    bool blend;
    GLenum lastSrcMode;
    GLenum lastDstMode;
    Program* currentProgram;

    GLuint meshBuffer;
    GLuint currentBuffer;

    TextureCache textureCache;
    LayerCache layerCache;
    GradientCache gradientCache;
    ProgramCache programCache;
    PathCache pathCache;
    PatchCache patchCache;
    TextDropShadowCache dropShadowCache;
    FboCache fboCache;
    GammaFontRenderer fontRenderer;

    Line line;
}; // class Caches

}; // namespace uirenderer

#ifdef USE_OPENGL_RENDERER
using namespace uirenderer;
ANDROID_SINGLETON_STATIC_INSTANCE(Caches);
#endif

}; // namespace android

#endif // ANDROID_UI_CACHES_H