/*
* Copyright 2011 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 GLES_V2_CONTEXT_H
#define GLES_V2_CONTEXT_H

#include <GLcommon/GLDispatch.h>
#include <GLcommon/GLEScontext.h>
#include <GLcommon/ShareGroup.h>

#include <memory>

// Extra desktop-specific OpenGL enums that we need to properly emulate OpenGL ES.
#define GL_FRAMEBUFFER_SRGB 0x8DB9
#define GL_TEXTURE_CUBE_MAP_SEAMLESS 0x884F
#define GL_DEPTH_CLAMP 0x864F

class ProgramData;
class TransformFeedbackData;

class GLESv2Context : public GLEScontext{
public:
    virtual void init(bool nativeTextureDecompressionEnabled) override;
    virtual const GLSupport* getCaps() const override {
        if (m_glesMajorVersion == 3 && m_glesMinorVersion == 1) {
            return &s_glSupportGles31;
        } else {
            return &s_glSupport;
        }
    }
    static void initGlobal(EGLiface* eglIface);
    GLESv2Context(int maj, int min, GlobalNameSpace* globalNameSpace,
            android::base::Stream* stream, GlLibrary* glLib);
    virtual ~GLESv2Context();

    enum class DrawCallCmd {
        Elements,
        ElementsInstanced,
        RangeElements,
        Arrays,
        ArraysInstanced,
    };

    void drawWithEmulations(
        DrawCallCmd cmd,
        GLenum mode,
        GLint first,
        GLsizei count,
        GLenum type,
        const GLvoid* indices,
        GLsizei primcount,
        GLuint start,
        GLuint end);

    void setupArraysPointers(GLESConversionArrays& fArrs,GLint first,GLsizei count,GLenum type,const GLvoid* indices,bool direct, bool* needEnablingPostDraw);
    void setVertexAttribDivisor(GLuint bindingindex, GLuint divisor);
    void setVertexAttribBindingIndex(GLuint attribindex, GLuint bindingindex);
    void setVertexAttribFormat(GLuint attribindex, GLint size, GLenum type, GLboolean normalized, GLuint reloffset, bool isInt = false);
    void setBindSampler(GLuint unit, GLuint sampler);
    int  getMaxCombinedTexUnits() override;
    int  getMaxTexUnits() override;

    void setAttribValue(int idx, unsigned int count, const GLfloat* val);
    // This whole att0 thing is about a incompatibility between GLES and OpenGL.
    // GLES allows a vertex shader attribute to be in location 0 and have a
    // current value, while OpenGL is not very clear about this, which results
    // in each implementation doing something different.
    void setAttribute0value(float x, float y, float z, float w);
    bool needAtt0PreDrawValidation();
    void validateAtt0PreDraw(unsigned int count);
    void validateAtt0PostDraw(void);
    const float* getAtt0(void) const {return m_attribute0value;}
    void setUseProgram(GLuint program, const ObjectDataPtr& programData);
    GLuint getCurrentProgram() const;
    ProgramData* getUseProgram();

    virtual void onSave(android::base::Stream* stream) const override;
    virtual ObjectDataPtr loadObject(NamedObjectType type,
            ObjectLocalName localName, android::base::Stream* stream) const
            override;

    virtual void initDefaultFBO(
            GLint width, GLint height, GLint colorFormat, GLint depthstencilFormat, GLint multisamples,
            GLuint* eglSurfaceRBColorId, GLuint* eglSurfaceRBDepthId,
            GLuint readWidth, GLint readHeight, GLint readColorFormat, GLint readDepthStencilFormat, GLint readMultisamples,
            GLuint* eglReadSurfaceRBColorId, GLuint* eglReadSurfaceRBDepthId) override;

    void initEmulatedBuffers();
    void initEmulatedVAO();

    unsigned int getTransformFeedbackGlobalName(ObjectLocalName p_localName);
    ObjectLocalName genTransformFeedbackName(ObjectLocalName p_localName = 0,
                                             bool genLocal = 0);
    void bindTransformFeedback(ObjectLocalName p_localName);
    ObjectLocalName getTransformFeedbackBinding();
    bool hasBoundTransformFeedback(ObjectLocalName transformFeedback);
    void deleteTransformFeedback(ObjectLocalName p_localName);
    GLuint getIndexedBuffer(GLenum target, GLuint index) override;
    void bindIndexedBuffer(GLenum target,
                           GLuint index,
                           GLuint buffer,
                           GLintptr offset,
                           GLsizeiptr size,
                           GLintptr stride = 0,
                           bool isBindBase = false) override;
    void bindIndexedBuffer(GLenum target, GLuint index, GLuint buffer) override;
    void unbindBuffer(GLuint buffer) override;

    static void setMaxGlesVersion(GLESVersion version);

    TransformFeedbackData* boundTransformFeedback();

    void enableArr(GLenum arr, bool enable) override;
    const GLESpointer* getPointer(GLenum arrType) override;

protected:
    void addVertexArrayObject(GLuint array) override;

    virtual void postLoadRestoreCtx();
    bool needConvert(GLESConversionArrays& fArrs,GLint first,GLsizei count,GLenum type,const GLvoid* indices,bool direct,GLESpointer* p,GLenum array_id);
private:
    void setupArrWithDataSize(GLsizei datasize, const GLvoid* arr,
                              GLenum arrayType, GLenum dataType,
                              GLint size, GLsizei stride, GLboolean normalized, int index, bool isInt, GLuint ptrBufferName, bool* needEnablingPostDraw);
    void initExtensionString();

    float m_attribute0value[4] = {};
    bool m_attribute0valueChanged = true;
    std::unique_ptr<GLfloat[]> m_att0Array = {};
    unsigned int m_att0ArrayLength = 0;
    bool m_att0NeedsDisable = false;

    ObjectDataPtr m_useProgramData = {};
    std::unordered_map<GLuint, GLuint> m_bindSampler;

    std::vector<GLuint> m_emulatedClientVBOs;
    GLuint m_emulatedClientIBO = 0;

    NameSpace* m_transformFeedbackNameSpace = nullptr;
    ObjectLocalName m_bindTransformFeedback = 0;
    bool m_transformFeedbackDeletePending = false;
};

#endif