/*
 * Copyright 2014 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */


#include "GrGLAssembleInterface.h"
#include "GrGLUtil.h"

#define GET_PROC(F) functions->f ## F = (GrGL ## F ## Proc) get(ctx, "gl" #F)
#define GET_PROC_SUFFIX(F, S) functions->f ## F = (GrGL ## F ## Proc) get(ctx, "gl" #F #S)
#define GET_PROC_LOCAL(F) GrGL ## F ## Proc F = (GrGL ## F ## Proc) get(ctx, "gl" #F)

// The glStencilThenCover* methods are a new addition to NV_path_rendering. They
// aren't available on all drivers. In the event that they are not present, this
// function can be used to add methods to the given GrGLInterface that emulate
// them using the existing glStencil*/glCover* methods.
static void emulate_nvpr_stencil_then_cover(GrGLInterface*);

const GrGLInterface* GrGLAssembleGLInterface(void* ctx, GrGLGetProc get) {
    GET_PROC_LOCAL(GetString);
    GET_PROC_LOCAL(GetStringi);
    GET_PROC_LOCAL(GetIntegerv);

    // GetStringi may be NULL depending on the GL version.
    if (NULL == GetString || NULL == GetIntegerv) {
        return NULL;
    }

    const char* versionString = (const char*) GetString(GR_GL_VERSION);
    GrGLVersion glVer = GrGLGetVersionFromString(versionString);

    if (glVer < GR_GL_VER(1,5) || GR_GL_INVALID_VER == glVer) {
        // We must have array and element_array buffer objects.
        return NULL;
    }

    GrGLExtensions extensions;
    if (!extensions.init(kGL_GrGLStandard, GetString, GetStringi, GetIntegerv)) {
        return NULL;
    }

    GrGLInterface* interface = SkNEW(GrGLInterface());
    GrGLInterface::Functions* functions = &interface->fFunctions;

    GET_PROC(ActiveTexture);
    GET_PROC(AttachShader);
    GET_PROC(BindAttribLocation);
    GET_PROC(BindBuffer);
    if (glVer >= GR_GL_VER(3,0)) {
        GET_PROC(BindFragDataLocation);
    }
    GET_PROC(BeginQuery);
    GET_PROC(BindTexture);
    GET_PROC(BlendFunc);

    if (glVer >= GR_GL_VER(1,4) ||
        extensions.has("GL_ARB_imaging") ||
        extensions.has("GL_EXT_blend_color")) {
        GET_PROC(BlendColor);
    }

    GET_PROC(BufferData);
    GET_PROC(BufferSubData);
    GET_PROC(Clear);
    GET_PROC(ClearColor);
    GET_PROC(ClearStencil);
    GET_PROC(ColorMask);
    GET_PROC(CompileShader);
    GET_PROC(CompressedTexImage2D);
    GET_PROC(CompressedTexSubImage2D);
    GET_PROC(CopyTexSubImage2D);
    GET_PROC(CreateProgram);
    GET_PROC(CreateShader);
    GET_PROC(CullFace);
    GET_PROC(DeleteBuffers);
    GET_PROC(DeleteProgram);
    GET_PROC(DeleteQueries);
    GET_PROC(DeleteShader);
    GET_PROC(DeleteTextures);
    GET_PROC(DepthMask);
    GET_PROC(Disable);
    GET_PROC(DisableVertexAttribArray);
    GET_PROC(DrawArrays);
    GET_PROC(DrawBuffer);
    GET_PROC(DrawBuffers);
    GET_PROC(DrawElements);
    GET_PROC(Enable);
    GET_PROC(EnableVertexAttribArray);
    GET_PROC(EndQuery);
    GET_PROC(Finish);
    GET_PROC(Flush);
    GET_PROC(FrontFace);
    GET_PROC(GenBuffers);
    GET_PROC(GenerateMipmap);
    GET_PROC(GetBufferParameteriv);
    GET_PROC(GetError);
    GET_PROC(GetIntegerv);
    GET_PROC(GetQueryObjectiv);
    GET_PROC(GetQueryObjectuiv);
    if (glVer >= GR_GL_VER(3,3) || extensions.has("GL_ARB_timer_query")) {
        GET_PROC(GetQueryObjecti64v);
        GET_PROC(GetQueryObjectui64v);
        GET_PROC(QueryCounter);
    } else if (extensions.has("GL_EXT_timer_query")) {
        GET_PROC_SUFFIX(GetQueryObjecti64v, EXT);
        GET_PROC_SUFFIX(GetQueryObjectui64v, EXT);
    }
    GET_PROC(GetQueryiv);
    GET_PROC(GetProgramInfoLog);
    GET_PROC(GetProgramiv);
    GET_PROC(GetShaderInfoLog);
    GET_PROC(GetShaderiv);
    GET_PROC(GetString);
    GET_PROC(GetStringi);
    GET_PROC(GetTexLevelParameteriv);
    GET_PROC(GenQueries);
    GET_PROC(GenTextures);
    GET_PROC(GetUniformLocation);
    GET_PROC(LineWidth);
    GET_PROC(LinkProgram);
    GET_PROC(MapBuffer);
    if (extensions.has("GL_EXT_direct_state_access")) {
        GET_PROC_SUFFIX(MatrixLoadf, EXT);
        GET_PROC_SUFFIX(MatrixLoadIdentity, EXT);
    }
    GET_PROC(PixelStorei);
    GET_PROC(ReadBuffer);
    GET_PROC(ReadPixels);
    GET_PROC(Scissor);
    GET_PROC(ShaderSource);
    GET_PROC(StencilFunc);
    GET_PROC(StencilFuncSeparate);
    GET_PROC(StencilMask);
    GET_PROC(StencilMaskSeparate);
    GET_PROC(StencilOp);
    GET_PROC(StencilOpSeparate);
    GET_PROC(TexImage2D);
    GET_PROC(TexParameteri);
    GET_PROC(TexParameteriv);
    if (glVer >= GR_GL_VER(4,2) || extensions.has("GL_ARB_texture_storage")) {
        GET_PROC(TexStorage2D);
    } else if (extensions.has("GL_EXT_texture_storage")) {
        GET_PROC_SUFFIX(TexStorage2D, EXT);
    }
    GET_PROC(TexSubImage2D);
    GET_PROC(Uniform1f);
    GET_PROC(Uniform1i);
    GET_PROC(Uniform1fv);
    GET_PROC(Uniform1iv);
    GET_PROC(Uniform2f);
    GET_PROC(Uniform2i);
    GET_PROC(Uniform2fv);
    GET_PROC(Uniform2iv);
    GET_PROC(Uniform3f);
    GET_PROC(Uniform3i);
    GET_PROC(Uniform3fv);
    GET_PROC(Uniform3iv);
    GET_PROC(Uniform4f);
    GET_PROC(Uniform4i);
    GET_PROC(Uniform4fv);
    GET_PROC(Uniform4iv);
    GET_PROC(UniformMatrix2fv);
    GET_PROC(UniformMatrix3fv);
    GET_PROC(UniformMatrix4fv);
    GET_PROC(UnmapBuffer);
    GET_PROC(UseProgram);
    GET_PROC(VertexAttrib4fv);
    GET_PROC(VertexAttribPointer);
    GET_PROC(Viewport);
    GET_PROC(BindFragDataLocationIndexed);

    if (glVer >= GR_GL_VER(3,0) || extensions.has("GL_ARB_vertex_array_object")) {
        // no ARB suffix for GL_ARB_vertex_array_object
        GET_PROC(BindVertexArray);
        GET_PROC(GenVertexArrays);
        GET_PROC(DeleteVertexArrays);
    }

    if (glVer >= GR_GL_VER(3,0) || extensions.has("GL_ARB_map_buffer_range")) {
        GET_PROC(MapBufferRange);
        GET_PROC(FlushMappedBufferRange);
    }

    // First look for GL3.0 FBO or GL_ARB_framebuffer_object (same since
    // GL_ARB_framebuffer_object doesn't use ARB suffix.)
    if (glVer >= GR_GL_VER(3,0) || extensions.has("GL_ARB_framebuffer_object")) {
        GET_PROC(GenFramebuffers);
        GET_PROC(GetFramebufferAttachmentParameteriv);
        GET_PROC(GetRenderbufferParameteriv);
        GET_PROC(BindFramebuffer);
        GET_PROC(FramebufferTexture2D);
        GET_PROC(CheckFramebufferStatus);
        GET_PROC(DeleteFramebuffers);
        GET_PROC(RenderbufferStorage);
        GET_PROC(GenRenderbuffers);
        GET_PROC(DeleteRenderbuffers);
        GET_PROC(FramebufferRenderbuffer);
        GET_PROC(BindRenderbuffer);
        GET_PROC(RenderbufferStorageMultisample);
        GET_PROC(BlitFramebuffer);
    } else if (extensions.has("GL_EXT_framebuffer_object")) {
        GET_PROC_SUFFIX(GenFramebuffers, EXT);
        GET_PROC_SUFFIX(GetFramebufferAttachmentParameteriv, EXT);
        GET_PROC_SUFFIX(GetRenderbufferParameteriv, EXT);
        GET_PROC_SUFFIX(BindFramebuffer, EXT);
        GET_PROC_SUFFIX(FramebufferTexture2D, EXT);
        GET_PROC_SUFFIX(CheckFramebufferStatus, EXT);
        GET_PROC_SUFFIX(DeleteFramebuffers, EXT);
        GET_PROC_SUFFIX(RenderbufferStorage, EXT);
        GET_PROC_SUFFIX(GenRenderbuffers, EXT);
        GET_PROC_SUFFIX(DeleteRenderbuffers, EXT);
        GET_PROC_SUFFIX(FramebufferRenderbuffer, EXT);
        GET_PROC_SUFFIX(BindRenderbuffer, EXT);
        if (extensions.has("GL_EXT_framebuffer_multisample")) {
            GET_PROC_SUFFIX(RenderbufferStorageMultisample, EXT);
        }
        if (extensions.has("GL_EXT_framebuffer_blit")) {
            GET_PROC_SUFFIX(BlitFramebuffer, EXT);
        }
    } else {
        // we must have FBOs
        delete interface;
        return NULL;
    }

    if (extensions.has("GL_NV_path_rendering")) {
        GET_PROC_SUFFIX(PathCommands, NV);
        GET_PROC_SUFFIX(PathCoords, NV);
        GET_PROC_SUFFIX(PathParameteri, NV);
        GET_PROC_SUFFIX(PathParameterf, NV);
        GET_PROC_SUFFIX(GenPaths, NV);
        GET_PROC_SUFFIX(DeletePaths, NV);
        GET_PROC_SUFFIX(IsPath, NV);
        GET_PROC_SUFFIX(PathStencilFunc, NV);
        GET_PROC_SUFFIX(StencilFillPath, NV);
        GET_PROC_SUFFIX(StencilStrokePath, NV);
        GET_PROC_SUFFIX(StencilFillPathInstanced, NV);
        GET_PROC_SUFFIX(StencilStrokePathInstanced, NV);
        GET_PROC_SUFFIX(PathTexGen, NV);
        GET_PROC_SUFFIX(CoverFillPath, NV);
        GET_PROC_SUFFIX(CoverStrokePath, NV);
        GET_PROC_SUFFIX(CoverFillPathInstanced, NV);
        GET_PROC_SUFFIX(CoverStrokePathInstanced, NV);
        GET_PROC_SUFFIX(StencilThenCoverFillPath, NV);
        GET_PROC_SUFFIX(StencilThenCoverStrokePath, NV);
        GET_PROC_SUFFIX(StencilThenCoverFillPathInstanced, NV);
        GET_PROC_SUFFIX(StencilThenCoverStrokePathInstanced, NV);
        GET_PROC_SUFFIX(ProgramPathFragmentInputGen, NV);

        if (NULL == interface->fFunctions.fStencilThenCoverFillPath ||
            NULL == interface->fFunctions.fStencilThenCoverStrokePath ||
            NULL == interface->fFunctions.fStencilThenCoverFillPathInstanced ||
            NULL == interface->fFunctions.fStencilThenCoverFillPathInstanced) {
            emulate_nvpr_stencil_then_cover(interface);
        }
    }

    if (extensions.has("GL_EXT_debug_marker")) {
        GET_PROC_SUFFIX(InsertEventMarker, EXT);
        GET_PROC_SUFFIX(PushGroupMarker, EXT);
        GET_PROC_SUFFIX(PopGroupMarker, EXT);
    }

    if (glVer >= GR_GL_VER(4,3) || extensions.has("GL_ARB_invalidate_subdata")) {
        GET_PROC(InvalidateBufferData);
        GET_PROC(InvalidateBufferSubData);
        GET_PROC(InvalidateFramebuffer);
        GET_PROC(InvalidateSubFramebuffer);
        GET_PROC(InvalidateTexImage);
        GET_PROC(InvalidateTexSubImage);
    }

    if (glVer >= GR_GL_VER(4,3) || extensions.has("GL_ARB_program_interface_query")) {
        GET_PROC(GetProgramResourceLocation);
    }

    interface->fStandard = kGL_GrGLStandard;
    interface->fExtensions.swap(&extensions);

    return interface;
}

static GrGLStencilFillPathProc gStencilFillPath;
static GrGLCoverFillPathProc gCoverFillPath;
static GrGLvoid GR_GL_FUNCTION_TYPE stencil_then_cover_fill_path(
                                        GrGLuint path, GrGLenum fillMode,
                                        GrGLuint mask, GrGLenum coverMode) {
    gStencilFillPath(path, fillMode, mask);
    gCoverFillPath(path, coverMode);
}


static GrGLStencilStrokePathProc gStencilStrokePath;
static GrGLCoverStrokePathProc gCoverStrokePath;
static GrGLvoid GR_GL_FUNCTION_TYPE stencil_then_cover_stroke_path(
                                        GrGLuint path, GrGLint reference,
                                        GrGLuint mask, GrGLenum coverMode) {
    gStencilStrokePath(path, reference, mask);
    gCoverStrokePath(path, coverMode);
}

static GrGLStencilFillPathInstancedProc gStencilFillPathInstanced;
static GrGLCoverFillPathInstancedProc gCoverFillPathInstanced;
static GrGLvoid GR_GL_FUNCTION_TYPE stencil_then_cover_fill_path_instanced(
                                        GrGLsizei numPaths, GrGLenum pathNameType,
                                        const GrGLvoid *paths, GrGLuint pathBase,
                                        GrGLenum fillMode, GrGLuint mask,
                                        GrGLenum coverMode, GrGLenum transformType,
                                        const GrGLfloat *transformValues) {
    gStencilFillPathInstanced(numPaths, pathNameType, paths, pathBase,
                              fillMode, mask, transformType, transformValues);
    gCoverFillPathInstanced(numPaths, pathNameType, paths, pathBase,
                            coverMode, transformType, transformValues);
}

static GrGLStencilStrokePathInstancedProc gStencilStrokePathInstanced;
static GrGLCoverStrokePathInstancedProc gCoverStrokePathInstanced;
static GrGLvoid GR_GL_FUNCTION_TYPE stencil_then_cover_stroke_path_instanced(
                                        GrGLsizei numPaths, GrGLenum pathNameType,
                                        const GrGLvoid *paths, GrGLuint pathBase,
                                        GrGLint reference, GrGLuint mask,
                                        GrGLenum coverMode, GrGLenum transformType,
                                        const GrGLfloat *transformValues) {
    gStencilStrokePathInstanced(numPaths, pathNameType, paths, pathBase,
                                reference, mask, transformType, transformValues);
    gCoverStrokePathInstanced(numPaths, pathNameType, paths, pathBase,
                              coverMode, transformType, transformValues);
}

static void emulate_nvpr_stencil_then_cover(GrGLInterface* interface) {
    if (NULL == gStencilFillPath) {
        gStencilFillPath = (GrGLStencilFillPathProc)interface->fFunctions.fStencilFillPath;
    }
    if (NULL == gCoverFillPath) {
        gCoverFillPath = (GrGLCoverFillPathProc)interface->fFunctions.fCoverFillPath;
    }
    if (NULL == gStencilStrokePath) {
        gStencilStrokePath = (GrGLStencilStrokePathProc)interface->fFunctions.fStencilStrokePath;
    }
    if (NULL == gCoverStrokePath) {
        gCoverStrokePath = (GrGLCoverStrokePathProc)interface->fFunctions.fCoverStrokePath;
    }
    if (NULL == gStencilFillPathInstanced) {
        gStencilFillPathInstanced = (GrGLStencilFillPathInstancedProc)
            interface->fFunctions.fStencilFillPathInstanced;
    }
    if (NULL == gCoverFillPathInstanced) {
        gCoverFillPathInstanced = (GrGLCoverFillPathInstancedProc)
            interface->fFunctions.fCoverFillPathInstanced;
    }
    if (NULL == gStencilStrokePathInstanced) {
        gStencilStrokePathInstanced = (GrGLStencilStrokePathInstancedProc)
            interface->fFunctions.fStencilStrokePathInstanced;
    }
    if (NULL == gCoverStrokePathInstanced) {
        gCoverStrokePathInstanced = (GrGLCoverStrokePathInstancedProc)
            interface->fFunctions.fCoverStrokePathInstanced;
    }

    if (interface->fFunctions.fStencilFillPath != gStencilFillPath ||
        interface->fFunctions.fCoverFillPath != gCoverFillPath ||
        interface->fFunctions.fStencilStrokePath != gStencilStrokePath ||
        interface->fFunctions.fCoverStrokePath != gCoverStrokePath ||
        interface->fFunctions.fStencilFillPathInstanced != gStencilFillPathInstanced ||
        interface->fFunctions.fCoverFillPathInstanced != gCoverFillPathInstanced ||
        interface->fFunctions.fStencilStrokePathInstanced != gStencilStrokePathInstanced ||
        interface->fFunctions.fCoverStrokePathInstanced != gCoverStrokePathInstanced) {
        // While not every windowing system requires GetProcAddress to return
        // the same addresses in different contexts, it is guaranteed to do so
        // in any context that supports NV_path_rendering.
        SkFAIL("GetProcAddress returned different addresses for the same nvpr functions");
        return;
    }

    interface->fFunctions.fStencilThenCoverFillPath = &stencil_then_cover_fill_path;
    interface->fFunctions.fStencilThenCoverStrokePath = &stencil_then_cover_stroke_path;
    interface->fFunctions.fStencilThenCoverFillPathInstanced = &stencil_then_cover_fill_path_instanced;
    interface->fFunctions.fStencilThenCoverStrokePathInstanced = &stencil_then_cover_stroke_path_instanced;
}