axmol/cocos/renderer/CCGLProgramState.h

/****************************************************************************
Copyright 2014 Chukong Technologies Inc.
 
http://www.cocos2d-x.org
 
Permission is hereby granted, free of charge, to any person obtaining a copy
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****************************************************************************/

#ifndef __CCGLPROGRAMSTATE_H__
#define __CCGLPROGRAMSTATE_H__

#include "base/ccTypes.h"
#include "base/CCVector.h"
#include "math/Vector2.h"
#include "math/Vector3.h"
#include "math/Vector4.h"

#include <unordered_map>

NS_CC_BEGIN

class GLProgram;
class Texture2D;
struct Uniform;
struct VertexAttrib;

//
//
// UniformValue
//
//
class UniformValue
{
    friend class GLProgram;

public:
    UniformValue();
    UniformValue(Uniform *uniform, GLProgram* glprogram);
    ~UniformValue();

    void setFloat(float value);
    void setInt(int value);
    void setVec2(const Vector2& value);
    void setVec3(const Vector3& value);
    void setVec4(const Vector4& value);
    void setMat4(const Matrix& value);
    void setCallback(const std::function<void(Uniform*)> &callback);
    void setTexture(GLuint textureId, GLuint activeTexture);

    void apply();

protected:
	Uniform* _uniform;  // weak ref
    GLProgram* _glprogram; // weak ref
    bool _useCallback;

    union U{
        float floatValue;
        int intValue;
        float v2Value[2];
        float v3Value[3];
        float v4Value[4];
        float matrixValue[16];
        struct {
            GLuint textureId;
            GLuint textureUnit;
        } tex;
        std::function<void(Uniform*)> *callback;

        U() { memset( this, 0, sizeof(*this) ); }
        ~U(){}
        U& operator=( const U& other ) {
            memcpy(this, &other, sizeof(*this));
            return *this;
        }
    } _value;
};

//
//
// VertexAttribValue
//
//
class VertexAttribValue
{
    friend class GLProgram;
    friend class GLProgramState;

public:
    VertexAttribValue(VertexAttrib *vertexAttrib);
    VertexAttribValue();
    ~VertexAttribValue();

	void setPointer(GLint size, GLenum type, GLboolean normalized, GLsizei stride, GLvoid *pointer);
    void setCallback(const std::function<void(VertexAttrib*)> &callback);
    void apply();

protected:
	VertexAttrib* _vertexAttrib;  // weak ref
    bool _useCallback;
    bool _enabled;

    union U{
        struct {
            GLint size;
            GLenum type;
            GLboolean normalized;
            GLsizei stride;
            GLvoid *pointer;
        } pointer;
        std::function<void(VertexAttrib*)> *callback;

        U() { memset( this, 0, sizeof(*this) ); }
        ~U(){}
        U& operator=( const U& other ) {
            memcpy(this, &other, sizeof(*this));
            return *this;
        }
    } _value;
};


/**
 GLProgramState holds the 'state' (uniforms and attributes) of the GLProgram.
 A GLProgram can be used by thousands of Nodes, but if different uniform values 
 are going to be used, then each node will need its own GLProgramState
 */
class GLProgramState : public Ref
{
    friend class GLProgramStateCache;
public:

    /** returns a new instance of GLProgramState for a given GLProgram */
    static GLProgramState* create(GLProgram* glprogram);

    /** gets-or-creates an instance of GLProgramState for a given GLProgram */
    static GLProgramState* getOrCreateWithGLProgram(GLProgram* glprogram);

    /** gets-or-creates an instance of GLProgramState for a given GLProgramName */
    static GLProgramState* getOrCreateWithGLProgramName(const std::string &glProgramName );

    void apply(const Matrix& modelView);

    void setGLProgram(GLProgram* glprogram);
    GLProgram* getGLProgram() const { return _glprogram; }

    // vertex attribs
    uint32_t getVertexAttribsFlags() const { return _vertexAttribsFlags; }
    ssize_t getVertexAttribCount() const { return _attributes.size(); }
    void setVertexAttribCallback(const std::string &name, const std::function<void(VertexAttrib*)> &callback);
    void setVertexAttribPointer(const std::string &name, GLint size, GLenum type, GLboolean normalized, GLsizei stride, GLvoid *pointer);

    // user defined uniforms
    ssize_t getUniformCount() const { return _uniforms.size(); }
    void setUniformInt(const std::string &uniformName, int value);
    void setUniformFloat(const std::string &uniformName, float value);
    void setUniformVec2(const std::string &uniformName, const Vector2& value);
    void setUniformVec3(const std::string &uniformName, const Vector3& value);
    void setUniformVec4(const std::string &uniformName, const Vector4& value);
    void setUniformMat4(const std::string &uniformName, const Matrix& value);
    void setUniformCallback(const std::string &uniformName, const std::function<void(Uniform*)> &callback);
    void setUniformTexture(const std::string &uniformName, Texture2D *texture);
    void setUniformTexture(const std::string &uniformName, GLuint textureId);

protected:
    GLProgramState();
    ~GLProgramState();
    bool init(GLProgram* program);
    void resetGLProgram();
    VertexAttribValue* getVertexAttribValue(const std::string &attributeName);
    UniformValue* getUniformValue(const std::string &uniformName);

    std::unordered_map<std::string, UniformValue> _uniforms;
    std::unordered_map<std::string, VertexAttribValue> _attributes;

    int _textureUnitIndex;
    uint32_t _vertexAttribsFlags;
    GLProgram *_glprogram;
};

NS_CC_END

#endif /* __CCGLPROGRAMSTATE_H__ */