src/OpenGL/libGLES_CM/Context.h

// SwiftShader Software Renderer
//
// Copyright(c) 2005-2013 TransGaming Inc.
//
// All rights reserved. No part of this software may be copied, distributed, transmitted,
// transcribed, stored in a retrieval system, translated into any human or computer
// language by any means, or disclosed to third parties without the explicit written
// agreement of TransGaming Inc. Without such an agreement, no rights or licenses, express
// or implied, including but not limited to any patent rights, are granted to you.
//

// Context.h: Defines the Context class, managing all GL state and performing
// rendering operations. It is the GLES2 specific implementation of EGLContext.

#ifndef LIBGLES_CM_CONTEXT_H_
#define LIBGLES_CM_CONTEXT_H_

#include "libEGL/Context.hpp"
#include "ResourceManager.h"
#include "common/NameSpace.hpp"
#include "common/Object.hpp"
#include "common/Image.hpp"
#include "Renderer/Sampler.hpp"
#include "common/MatrixStack.hpp"

#include <GLES/gl.h>
#include <GLES/glext.h>
#include <EGL/egl.h>

#include <map>
#include <string>

namespace egl
{
class Display;
class Surface;
class Config;
}

namespace es1
{
struct TranslatedAttribute;
struct TranslatedIndexData;

class Device;
class Buffer;
class Texture;
class Texture2D;
class TextureExternal;
class Framebuffer;
class Renderbuffer;
class RenderbufferStorage;
class Colorbuffer;
class Depthbuffer;
class StreamingIndexBuffer;
class Stencilbuffer;
class DepthStencilbuffer;
class VertexDataManager;
class IndexDataManager;

enum
{
    MAX_VERTEX_ATTRIBS = VERTEX_ATTRIBUTES,
    MAX_VARYING_VECTORS = 10,
    MAX_TEXTURE_UNITS = 2,
    MAX_DRAW_BUFFERS = 1,
	MAX_LIGHTS = 8,

	MAX_MODELVIEW_STACK_DEPTH = 32,
	MAX_PROJECTION_STACK_DEPTH = 2,
	MAX_TEXTURE_STACK_DEPTH = 2,
};

const GLenum compressedTextureFormats[] =
{
	GL_ETC1_RGB8_OES,
#if (S3TC_SUPPORT)
	GL_COMPRESSED_RGB_S3TC_DXT1_EXT,
	GL_COMPRESSED_RGBA_S3TC_DXT1_EXT,
#endif
};

const GLint NUM_COMPRESSED_TEXTURE_FORMATS = sizeof(compressedTextureFormats) / sizeof(compressedTextureFormats[0]);

const GLint multisampleCount[] = {4, 2, 1};
const GLint NUM_MULTISAMPLE_COUNTS = sizeof(multisampleCount) / sizeof(multisampleCount[0]);
const GLint IMPLEMENTATION_MAX_SAMPLES = multisampleCount[0];

const float ALIASED_LINE_WIDTH_RANGE_MIN = 1.0f;
const float ALIASED_LINE_WIDTH_RANGE_MAX = 1.0f;
const float ALIASED_POINT_SIZE_RANGE_MIN = 0.125f;
const float ALIASED_POINT_SIZE_RANGE_MAX = 8192.0f;
const float SMOOTH_LINE_WIDTH_RANGE_MIN = 1.0f;
const float SMOOTH_LINE_WIDTH_RANGE_MAX = 1.0f;
const float SMOOTH_POINT_SIZE_RANGE_MIN = 0.125f;
const float SMOOTH_POINT_SIZE_RANGE_MAX = 8192.0f;
const float MAX_TEXTURE_MAX_ANISOTROPY = 16.0f;

struct Color
{
    float red;
    float green;
    float blue;
    float alpha;
};

struct Point
{
	float x;
	float y;
	float z;
	float w;
};

struct Vector
{
	float x;
	float y;
	float z;
};

struct Attenuation
{
	float constant;
	float linear;
	float quadratic;
};

struct Light
{
	bool enabled;
	Color ambient;
	Color diffuse;
	Color specular;
	Point position;
	Vector direction;
	Attenuation attenuation;
	float spotExponent;
	float spotCutoffAngle;
};

// Helper structure describing a single vertex attribute
class VertexAttribute
{
public:
    VertexAttribute() : mType(GL_FLOAT), mSize(4), mNormalized(false), mStride(0), mPointer(NULL), mArrayEnabled(false)
    {
        mCurrentValue[0] = 0.0f;
        mCurrentValue[1] = 0.0f;
        mCurrentValue[2] = 0.0f;
        mCurrentValue[3] = 1.0f;
    }

    int typeSize() const
    {
        switch(mType)
        {
        case GL_BYTE:           return mSize * sizeof(GLbyte);
        case GL_UNSIGNED_BYTE:  return mSize * sizeof(GLubyte);
        case GL_SHORT:          return mSize * sizeof(GLshort);
        case GL_UNSIGNED_SHORT: return mSize * sizeof(GLushort);
        case GL_FIXED:          return mSize * sizeof(GLfixed);
        case GL_FLOAT:          return mSize * sizeof(GLfloat);
        default: UNREACHABLE(mType); return mSize * sizeof(GLfloat);
        }
    }

    GLsizei stride() const
    {
        return mStride ? mStride : typeSize();
    }

    // From glVertexAttribPointer
    GLenum mType;
    GLint mSize;
    bool mNormalized;
    GLsizei mStride;   // 0 means natural stride

    union
    {
        const void *mPointer;
        intptr_t mOffset;
    };

    gl::BindingPointer<Buffer> mBoundBuffer;   // Captured when glVertexAttribPointer is called.

    bool mArrayEnabled;   // From glEnable/DisableVertexAttribArray
    float mCurrentValue[4];   // From glVertexAttrib
};

typedef VertexAttribute VertexAttributeArray[MAX_VERTEX_ATTRIBS];

struct TextureUnit
{
	Color color;
	GLenum environmentMode;
	GLenum combineRGB;
	GLenum combineAlpha;
	GLenum src0RGB;
	GLenum src0Alpha;
	GLenum src1RGB;
	GLenum src1Alpha;
	GLenum src2RGB;
	GLenum src2Alpha;
	GLenum operand0RGB;
	GLenum operand0Alpha;
	GLenum operand1RGB;
	GLenum operand1Alpha;
	GLenum operand2RGB;
	GLenum operand2Alpha;
};

// Helper structure to store all raw state
struct State
{
    Color colorClearValue;
    GLclampf depthClearValue;
    int stencilClearValue;

    bool cullFaceEnabled;
    GLenum cullMode;
    GLenum frontFace;
    bool depthTestEnabled;
    GLenum depthFunc;
    bool blendEnabled;
    GLenum sourceBlendRGB;
    GLenum destBlendRGB;
    GLenum sourceBlendAlpha;
    GLenum destBlendAlpha;
    GLenum blendEquationRGB;
    GLenum blendEquationAlpha;
    bool stencilTestEnabled;
    GLenum stencilFunc;
    GLint stencilRef;
    GLuint stencilMask;
    GLenum stencilFail;
    GLenum stencilPassDepthFail;
    GLenum stencilPassDepthPass;
    GLuint stencilWritemask;
    bool polygonOffsetFillEnabled;
    GLfloat polygonOffsetFactor;
    GLfloat polygonOffsetUnits;
    bool sampleAlphaToCoverageEnabled;
    bool sampleCoverageEnabled;
    GLclampf sampleCoverageValue;
    bool sampleCoverageInvert;
    bool scissorTestEnabled;
    bool ditherEnabled;
	GLenum shadeModel;

    GLfloat lineWidth;

    GLenum generateMipmapHint;
	GLenum perspectiveCorrectionHint;
	GLenum fogHint;

    GLint viewportX;
    GLint viewportY;
    GLsizei viewportWidth;
    GLsizei viewportHeight;
    float zNear;
    float zFar;

    GLint scissorX;
    GLint scissorY;
    GLsizei scissorWidth;
    GLsizei scissorHeight;

    bool colorMaskRed;
    bool colorMaskGreen;
    bool colorMaskBlue;
    bool colorMaskAlpha;
    bool depthMask;

    unsigned int activeSampler;   // Active texture unit selector - GL_TEXTURE0
    gl::BindingPointer<Buffer> arrayBuffer;
    gl::BindingPointer<Buffer> elementArrayBuffer;
    GLuint framebuffer;
    gl::BindingPointer<Renderbuffer> renderbuffer;

    VertexAttribute vertexAttribute[MAX_VERTEX_ATTRIBS];
    gl::BindingPointer<Texture> samplerTexture[TEXTURE_TYPE_COUNT][MAX_TEXTURE_UNITS];

    GLint unpackAlignment;
    GLint packAlignment;

	TextureUnit textureUnit[MAX_TEXTURE_UNITS];
};

class Context : public egl::Context
{
public:
    Context(const egl::Config *config, const Context *shareContext);

	virtual void makeCurrent(egl::Surface *surface);
	virtual int getClientVersion() const;
    virtual void finish();

    void markAllStateDirty();

    // State manipulation
    void setClearColor(float red, float green, float blue, float alpha);
    void setClearDepth(float depth);
    void setClearStencil(int stencil);

    void setCullFaceEnabled(bool enabled);
    bool isCullFaceEnabled() const;
    void setCullMode(GLenum mode);
    void setFrontFace(GLenum front);

    void setDepthTestEnabled(bool enabled);
    bool isDepthTestEnabled() const;
    void setDepthFunc(GLenum depthFunc);
    void setDepthRange(float zNear, float zFar);

	void setAlphaTestEnabled(bool enabled);
    bool isAlphaTestEnabled() const;
    void setAlphaFunc(GLenum alphaFunc, GLclampf reference);

    void setBlendEnabled(bool enabled);
    bool isBlendEnabled() const;
    void setBlendFactors(GLenum sourceRGB, GLenum destRGB, GLenum sourceAlpha, GLenum destAlpha);
    void setBlendEquation(GLenum rgbEquation, GLenum alphaEquation);

    void setStencilTestEnabled(bool enabled);
    bool isStencilTestEnabled() const;
    void setStencilParams(GLenum stencilFunc, GLint stencilRef, GLuint stencilMask);
    void setStencilWritemask(GLuint stencilWritemask);
    void setStencilOperations(GLenum stencilFail, GLenum stencilPassDepthFail, GLenum stencilPassDepthPass);

    void setPolygonOffsetFillEnabled(bool enabled);
    bool isPolygonOffsetFillEnabled() const;
    void setPolygonOffsetParams(GLfloat factor, GLfloat units);

    void setSampleAlphaToCoverageEnabled(bool enabled);
    bool isSampleAlphaToCoverageEnabled() const;
    void setSampleCoverageEnabled(bool enabled);
    bool isSampleCoverageEnabled() const;
    void setSampleCoverageParams(GLclampf value, bool invert);

	void setShadeModel(GLenum mode);
    void setDitherEnabled(bool enabled);
    bool isDitherEnabled() const;
	void setLightingEnabled(bool enabled);
	bool isLightingEnabled() const;
	void setLightEnabled(int index, bool enable);
	bool isLightEnabled(int index) const;
	void setLightAmbient(int index, float r, float g, float b, float a);
	void setLightDiffuse(int index, float r, float g, float b, float a);
	void setLightSpecular(int index, float r, float g, float b, float a);
	void setLightPosition(int index, float x, float y, float z, float w);
	void setLightDirection(int index, float x, float y, float z);
	void setLightAttenuationConstant(int index, float constant);
	void setLightAttenuationLinear(int index, float linear);
	void setLightAttenuationQuadratic(int index, float quadratic);
	void setSpotLightExponent(int index, float exponent);
	void setSpotLightCutoff(int index, float cutoff);

	void setGlobalAmbient(float red, float green, float blue, float alpha);
	void setMaterialAmbient(float red, float green, float blue, float alpha);
	void setMaterialDiffuse(float red, float green, float blue, float alpha);
	void setMaterialSpecular(float red, float green, float blue, float alpha);
	void setMaterialEmission(float red, float green, float blue, float alpha);
	void setMaterialShininess(float shininess);
	void setLightModelTwoSide(bool enable);

	void setFogEnabled(bool enabled);
	bool isFogEnabled() const;
	void setFogMode(GLenum mode);
	void setFogDensity(float fogDensity);
	void setFogStart(float fogStart);
	void setFogEnd(float fogEnd);
	void setFogColor(float r, float g, float b, float a);

    void setTexture2Denabled(bool enabled);
	bool isTexture2Denabled() const;
	void setTextureExternalEnabled(bool enabled);
	bool isTextureExternalEnabled() const;
    void clientActiveTexture(GLenum texture);
	GLenum getClientActiveTexture() const;
	unsigned int getActiveTexture() const;

	void setTextureEnvMode(GLenum texEnvMode);
	void setTextureEnvColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha);
	void setCombineRGB(GLenum combineRGB);
	void setCombineAlpha(GLenum combineAlpha);
	void setOperand0RGB(GLenum operand);
	void setOperand1RGB(GLenum operand);
	void setOperand2RGB(GLenum operand);
	void setOperand0Alpha(GLenum operand);
	void setOperand1Alpha(GLenum operand);
	void setOperand2Alpha(GLenum operand);
	void setSrc0RGB(GLenum src);
	void setSrc1RGB(GLenum src);
	void setSrc2RGB(GLenum src);
	void setSrc0Alpha(GLenum src);
	void setSrc1Alpha(GLenum src);
	void setSrc2Alpha(GLenum src);

    void setLineWidth(GLfloat width);

    void setGenerateMipmapHint(GLenum hint);
	void setPerspectiveCorrectionHint(GLenum hint);
	void setFogHint(GLenum hint);

    void setViewportParams(GLint x, GLint y, GLsizei width, GLsizei height);

	void setScissorTestEnabled(bool enabled);
    bool isScissorTestEnabled() const;
    void setScissorParams(GLint x, GLint y, GLsizei width, GLsizei height);

    void setColorMask(bool red, bool green, bool blue, bool alpha);
    void setDepthMask(bool mask);

    void setActiveSampler(unsigned int active);

    GLuint getFramebufferName() const;
    GLuint getRenderbufferName() const;

    GLuint getArrayBufferName() const;

    void setVertexAttribArrayEnabled(unsigned int attribNum, bool enabled);
    const VertexAttribute &getVertexAttribState(unsigned int attribNum);
    void setVertexAttribState(unsigned int attribNum, Buffer *boundBuffer, GLint size, GLenum type,
                              bool normalized, GLsizei stride, const void *pointer);
    const void *getVertexAttribPointer(unsigned int attribNum) const;

    const VertexAttributeArray &getVertexAttributes();

    void setUnpackAlignment(GLint alignment);
    GLint getUnpackAlignment() const;

    void setPackAlignment(GLint alignment);
    GLint getPackAlignment() const;

    // These create and destroy methods are merely pass-throughs to
    // ResourceManager, which owns these object types
    GLuint createBuffer();
    GLuint createTexture();
    GLuint createRenderbuffer();

    void deleteBuffer(GLuint buffer);
    void deleteTexture(GLuint texture);
    void deleteRenderbuffer(GLuint renderbuffer);

    // Framebuffers are owned by the Context, so these methods do not pass through
    GLuint createFramebuffer();
    void deleteFramebuffer(GLuint framebuffer);

    void bindArrayBuffer(GLuint buffer);
    void bindElementArrayBuffer(GLuint buffer);
    void bindTexture2D(GLuint texture);
    void bindTextureExternal(GLuint texture);
    void bindFramebuffer(GLuint framebuffer);
    void bindRenderbuffer(GLuint renderbuffer);

    void setFramebufferZero(Framebuffer *framebuffer);

    void setRenderbufferStorage(RenderbufferStorage *renderbuffer);

    void setVertexAttrib(GLuint index, GLfloat x, GLfloat y, GLfloat z, GLfloat w);

    Buffer *getBuffer(GLuint handle);
    virtual Texture *getTexture(GLuint handle);
    Framebuffer *getFramebuffer(GLuint handle);
    virtual Renderbuffer *getRenderbuffer(GLuint handle);

    Buffer *getArrayBuffer();
    Buffer *getElementArrayBuffer();
    Texture2D *getTexture2D();
    TextureExternal *getTextureExternal();
    Texture *getSamplerTexture(unsigned int sampler, TextureType type);
    Framebuffer *getFramebuffer();

    bool getFloatv(GLenum pname, GLfloat *params);
    bool getIntegerv(GLenum pname, GLint *params);
    bool getBooleanv(GLenum pname, GLboolean *params);
    bool getPointerv(GLenum pname, const GLvoid **params);

    int getQueryParameterNum(GLenum pname);
	bool isQueryParameterInt(GLenum pname);
	bool isQueryParameterFloat(GLenum pname);
	bool isQueryParameterBool(GLenum pname);
	bool isQueryParameterPointer(GLenum pname);

    void readPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLsizei *bufSize, void* pixels);
    void clear(GLbitfield mask);
    void drawArrays(GLenum mode, GLint first, GLsizei count);
    void drawElements(GLenum mode, GLsizei count, GLenum type, const void *indices);
    void drawTexture(GLfloat x, GLfloat y, GLfloat z, GLfloat width, GLfloat height);
    void flush();

    void recordInvalidEnum();
    void recordInvalidValue();
    void recordInvalidOperation();
    void recordOutOfMemory();
    void recordInvalidFramebufferOperation();
	void recordMatrixStackOverflow();
	void recordMatrixStackUnderflow();

    GLenum getError();

    static int getSupportedMultisampleCount(int requested);

	virtual void bindTexImage(egl::Surface *surface);
	virtual EGLenum validateSharedImage(EGLenum target, GLuint name, GLuint textureLevel);
	virtual egl::Image *createSharedImage(EGLenum target, GLuint name, GLuint textureLevel);

	Device *getDevice();

    void setMatrixMode(GLenum mode);
    void loadIdentity();
	void load(const GLfloat *m);
    void pushMatrix();
    void popMatrix();
    void rotate(GLfloat angle, GLfloat x, GLfloat y, GLfloat z);
    void translate(GLfloat x, GLfloat y, GLfloat z);
	void scale(GLfloat x, GLfloat y, GLfloat z);
    void multiply(const GLfloat *m);
	void frustum(GLfloat left, GLfloat right, GLfloat bottom, GLfloat top, GLfloat zNear, GLfloat zFar);
    void ortho(GLfloat left, GLfloat right, GLfloat bottom, GLfloat top, GLfloat zNear, GLfloat zFar);

	void setClipPlane(int index, const float plane[4]);
	void setClipPlaneEnabled(int index, bool enable);
	bool isClipPlaneEnabled(int index) const;

	void setColorLogicOpEnabled(bool enable);
	bool isColorLogicOpEnabled() const;
	void setLogicalOperation(GLenum logicOp);

	void setPointSmoothEnabled(bool enable);
	bool isPointSmoothEnabled() const;

	void setLineSmoothEnabled(bool enable);
	bool isLineSmoothEnabled() const;

	void setColorMaterialEnabled(bool enable);
	bool isColorMaterialEnabled() const;

	void setNormalizeEnabled(bool enable);
	bool isNormalizeEnabled() const;

	void setRescaleNormalEnabled(bool enable);
	bool isRescaleNormalEnabled() const;

	void setVertexArrayEnabled(bool enable);
	bool isVertexArrayEnabled() const;

	void setNormalArrayEnabled(bool enable);
	bool isNormalArrayEnabled() const;

	void setColorArrayEnabled(bool enable);
	bool isColorArrayEnabled() const;

	void setPointSizeArrayEnabled(bool enable);
	bool isPointSizeArrayEnabled() const;

	void setTextureCoordArrayEnabled(bool enable);
	bool isTextureCoordArrayEnabled() const;

	void setMultisampleEnabled(bool enable);
	bool isMultisampleEnabled() const;

	void setSampleAlphaToOneEnabled(bool enable);
	bool isSampleAlphaToOneEnabled() const;

	void setPointSpriteEnabled(bool enable);
	bool isPointSpriteEnabled() const;
	void setPointSizeMin(float min);
	void setPointSizeMax(float max);
	void setPointDistanceAttenuation(float a, float b, float c);
	void setPointFadeThresholdSize(float threshold);

private:
	virtual ~Context();

    bool applyRenderTarget();
    void applyState(GLenum drawMode);
    GLenum applyVertexBuffer(GLint base, GLint first, GLsizei count);
    GLenum applyIndexBuffer(const void *indices, GLsizei count, GLenum mode, GLenum type, TranslatedIndexData *indexInfo);
    void applyTextures();
	void applyTexture(int sampler, Texture *texture);

    void detachBuffer(GLuint buffer);
    void detachTexture(GLuint texture);
    void detachFramebuffer(GLuint framebuffer);
    void detachRenderbuffer(GLuint renderbuffer);

    bool cullSkipsDraw(GLenum drawMode);
    bool isTriangleMode(GLenum drawMode);

    State mState;

    gl::BindingPointer<Texture2D> mTexture2DZero;
    gl::BindingPointer<TextureExternal> mTextureExternalZero;

    typedef std::map<GLint, Framebuffer*> FramebufferMap;
    FramebufferMap mFramebufferMap;
    gl::NameSpace mFramebufferNameSpace;

    VertexDataManager *mVertexDataManager;
    IndexDataManager *mIndexDataManager;

	bool lightingEnabled;
	Light light[MAX_LIGHTS];
	Color globalAmbient;
	Color materialAmbient;
	Color materialDiffuse;
	Color materialSpecular;
	Color materialEmission;
	GLfloat materialShininess;
	bool lightModelTwoSide;

    // Recorded errors
    bool mInvalidEnum;
    bool mInvalidValue;
    bool mInvalidOperation;
    bool mOutOfMemory;
    bool mInvalidFramebufferOperation;
	bool mMatrixStackOverflow;
	bool mMatrixStackUnderflow;

    bool mHasBeenCurrent;

    // state caching flags
    bool mDepthStateDirty;
    bool mMaskStateDirty;
    bool mBlendStateDirty;
    bool mStencilStateDirty;
    bool mPolygonOffsetStateDirty;
    bool mSampleStateDirty;
    bool mFrontFaceDirty;
    bool mDitherStateDirty;

	sw::MatrixStack &currentMatrixStack();
	GLenum matrixMode;
    sw::MatrixStack modelViewStack;
	sw::MatrixStack projectionStack;
	sw::MatrixStack textureStack0;
	sw::MatrixStack textureStack1;

	bool texture2Denabled[MAX_TEXTURE_UNITS];
	bool textureExternalEnabled[MAX_TEXTURE_UNITS];
	GLenum clientTexture;

	int clipFlags;

	bool alphaTestEnabled;
	GLenum alphaTestFunc;
	float alphaTestRef;

	bool fogEnabled;
	GLenum fogMode;
	float fogDensity;
	float fogStart;
	float fogEnd;
	Color fogColor;

	bool lineSmoothEnabled;
	bool colorMaterialEnabled;
	bool normalizeEnabled;
	bool rescaleNormalEnabled;
	bool multisampleEnabled;
	bool sampleAlphaToOneEnabled;

	bool pointSpriteEnabled;
	bool pointSmoothEnabled;
	float pointSizeMin;
	float pointSizeMax;
	Attenuation pointDistanceAttenuation;
	float pointFadeThresholdSize;

	bool colorLogicOpEnabled;
	GLenum logicalOperation;

	Device *device;
    ResourceManager *mResourceManager;
};
}

#endif   // INCLUDE_CONTEXT_H_