gecko-dev/gfx/gl/SkiaGLGlue.cpp

/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 4; -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "skia/include/gpu/GrContext.h"
#include "skia/include/gpu/gl/GrGLInterface.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/ThreadLocal.h"
#include "mozilla/DebugOnly.h"

/* SkPostConfig.h includes windows.h, which includes windef.h
 * which redefines min/max. We don't want that. */
#ifdef _WIN32
#  undef min
#  undef max
#endif

#include "GLContext.h"
#include "SkiaGLGlue.h"

using mozilla::gl::GLContext;
using mozilla::gl::GLFeature;
using mozilla::gl::SkiaGLGlue;

template <typename R, typename... A>
static inline GrGLFunction<R (*)(A...)> WrapGL(RefPtr<GLContext> aContext,
                                               R (GLContext::*aFunc)(A...)) {
  return [aContext, aFunc](A... args) -> R {
    aContext->MakeCurrent();
    return (aContext->*aFunc)(args...);
  };
}

template <typename R, typename... A>
static inline GrGLFunction<R (*)(A...)> WrapGL(RefPtr<GLContext> aContext,
                                               R (*aFunc)(GLContext*, A...)) {
  return [aContext, aFunc](A... args) -> R {
    aContext->MakeCurrent();
    return (*aFunc)(aContext, args...);
  };
}

// Core GL functions required by Ganesh

static const GLubyte* glGetString_mozilla(GLContext* aContext, GrGLenum aName) {
  // GLContext only exposes a OpenGL 2.0 style API, so we have to intercept a
  // bunch of checks that Ganesh makes to determine which capabilities are
  // present on the GL implementation and change them to match what GLContext
  // actually exposes.

  if (aName == LOCAL_GL_VERSION) {
    if (aContext->IsGLES()) {
      return reinterpret_cast<const GLubyte*>("OpenGL ES 2.0");
    }
    return reinterpret_cast<const GLubyte*>("2.0");
  } else if (aName == LOCAL_GL_EXTENSIONS) {
    // Only expose the bare minimum extensions we want to support to ensure a
    // functional Ganesh as GLContext only exposes certain extensions
    static bool extensionsStringBuilt = false;
    static char extensionsString[1024];

    if (!extensionsStringBuilt) {
      extensionsString[0] = '\0';

      if (aContext->IsGLES()) {
        // OES is only applicable to GLES2
        if (aContext->IsExtensionSupported(
                GLContext::OES_packed_depth_stencil)) {
          strcat(extensionsString, "GL_OES_packed_depth_stencil ");
        }

        if (aContext->IsExtensionSupported(GLContext::OES_rgb8_rgba8)) {
          strcat(extensionsString, "GL_OES_rgb8_rgba8 ");
        }

        if (aContext->IsExtensionSupported(GLContext::OES_texture_npot)) {
          strcat(extensionsString, "GL_OES_texture_npot ");
        }

        if (aContext->IsExtensionSupported(
                GLContext::OES_vertex_array_object)) {
          strcat(extensionsString, "GL_OES_vertex_array_object ");
        }

        if (aContext->IsSupported(GLFeature::standard_derivatives)) {
          strcat(extensionsString, "GL_OES_standard_derivatives ");
        }
      } else {
        if (aContext->IsSupported(GLFeature::framebuffer_object)) {
          strcat(extensionsString, "GL_ARB_framebuffer_object ");
        } else if (aContext->IsExtensionSupported(
                       GLContext::EXT_framebuffer_object)) {
          strcat(extensionsString, "GL_EXT_framebuffer_object ");
        }

        if (aContext->IsSupported(GLFeature::texture_rg)) {
          strcat(extensionsString, "GL_ARB_texture_rg ");
        }
      }

      if (aContext->IsExtensionSupported(
              GLContext::EXT_texture_format_BGRA8888)) {
        strcat(extensionsString, "GL_EXT_texture_format_BGRA8888 ");
      }

      if (aContext->IsExtensionSupported(GLContext::EXT_packed_depth_stencil)) {
        strcat(extensionsString, "GL_EXT_packed_depth_stencil ");
      }

      if (aContext->IsExtensionSupported(GLContext::EXT_bgra)) {
        strcat(extensionsString, "GL_EXT_bgra ");
      }

      if (aContext->IsExtensionSupported(GLContext::EXT_read_format_bgra)) {
        strcat(extensionsString, "GL_EXT_read_format_bgra ");
      }

      extensionsStringBuilt = true;
#ifdef DEBUG
      printf_stderr("Exported SkiaGL extensions: %s\n", extensionsString);
#endif
    }

    return reinterpret_cast<const GLubyte*>(extensionsString);

  } else if (aName == LOCAL_GL_SHADING_LANGUAGE_VERSION) {
    if (aContext->IsGLES()) {
      return reinterpret_cast<const GLubyte*>("OpenGL ES GLSL ES 1.0");
    }
    return reinterpret_cast<const GLubyte*>("1.10");
  }

  return aContext->fGetString(aName);
}

static GrGLInterface* CreateGrGLInterfaceFromGLContext(GLContext* context) {
  auto* i = new GrGLInterface();

  context->MakeCurrent();

  // We support both desktop GL and GLES2
  if (context->IsGLES()) {
    i->fStandard = kGLES_GrGLStandard;
  } else {
    i->fStandard = kGL_GrGLStandard;
  }

  GrGLFunction<GrGLGetStringFn> getString =
      WrapGL(context, &glGetString_mozilla);
  GrGLFunction<GrGLGetIntegervFn> getIntegerv =
      WrapGL(context, &GLContext::fGetIntegerv);

  GrGLExtensions extensions;
  if (!extensions.init(i->fStandard, getString, nullptr, getIntegerv)) {
    delete i;
    return nullptr;
  }

  i->fExtensions.swap(&extensions);

  // Core GL functions required by Ganesh
  i->fFunctions.fActiveTexture = WrapGL(context, &GLContext::fActiveTexture);
  i->fFunctions.fAttachShader = WrapGL(context, &GLContext::fAttachShader);
  i->fFunctions.fBindAttribLocation =
      WrapGL(context, &GLContext::fBindAttribLocation);
  i->fFunctions.fBindBuffer = WrapGL(context, &GLContext::fBindBuffer);
  i->fFunctions.fBindFramebuffer =
      WrapGL(context, &GLContext::fBindFramebuffer);
  i->fFunctions.fBindRenderbuffer =
      WrapGL(context, &GLContext::fBindRenderbuffer);
  i->fFunctions.fBindTexture = WrapGL(context, &GLContext::fBindTexture);
  i->fFunctions.fBlendFunc = WrapGL(context, &GLContext::fBlendFunc);
  i->fFunctions.fBlendColor = WrapGL(context, &GLContext::fBlendColor);
  i->fFunctions.fBlendEquation = WrapGL(context, &GLContext::fBlendEquation);
  i->fFunctions.fBufferData = WrapGL(context, &GLContext::fBufferData);
  i->fFunctions.fBufferSubData = WrapGL(context, &GLContext::fBufferSubData);
  i->fFunctions.fCheckFramebufferStatus =
      WrapGL(context, &GLContext::fCheckFramebufferStatus);
  i->fFunctions.fClear = WrapGL(context, &GLContext::fClear);
  i->fFunctions.fClearColor = WrapGL(context, &GLContext::fClearColor);
  i->fFunctions.fClearStencil = WrapGL(context, &GLContext::fClearStencil);
  i->fFunctions.fColorMask = WrapGL(context, &GLContext::fColorMask);
  i->fFunctions.fCompileShader = WrapGL(context, &GLContext::fCompileShader);
  i->fFunctions.fCompressedTexImage2D =
      WrapGL(context, &GLContext::fCompressedTexImage2D);
  i->fFunctions.fCompressedTexSubImage2D =
      WrapGL(context, &GLContext::fCompressedTexSubImage2D);
  i->fFunctions.fCopyTexSubImage2D =
      WrapGL(context, &GLContext::fCopyTexSubImage2D);
  i->fFunctions.fCreateProgram = WrapGL(context, &GLContext::fCreateProgram);
  i->fFunctions.fCreateShader = WrapGL(context, &GLContext::fCreateShader);
  i->fFunctions.fCullFace = WrapGL(context, &GLContext::fCullFace);
  i->fFunctions.fDeleteBuffers = WrapGL(context, &GLContext::fDeleteBuffers);
  i->fFunctions.fDeleteFramebuffers =
      WrapGL(context, &GLContext::fDeleteFramebuffers);
  i->fFunctions.fDeleteProgram = WrapGL(context, &GLContext::fDeleteProgram);
  i->fFunctions.fDeleteRenderbuffers =
      WrapGL(context, &GLContext::fDeleteRenderbuffers);
  i->fFunctions.fDeleteShader = WrapGL(context, &GLContext::fDeleteShader);
  i->fFunctions.fDeleteTextures = WrapGL(context, &GLContext::fDeleteTextures);
  i->fFunctions.fDepthMask = WrapGL(context, &GLContext::fDepthMask);
  i->fFunctions.fDisable = WrapGL(context, &GLContext::fDisable);
  i->fFunctions.fDisableVertexAttribArray =
      WrapGL(context, &GLContext::fDisableVertexAttribArray);
  i->fFunctions.fDrawArrays = WrapGL(context, &GLContext::fDrawArrays);
  i->fFunctions.fDrawElements = WrapGL(context, &GLContext::fDrawElements);
  i->fFunctions.fDrawRangeElements =
      WrapGL(context, &GLContext::fDrawRangeElements);
  i->fFunctions.fEnable = WrapGL(context, &GLContext::fEnable);
  i->fFunctions.fEnableVertexAttribArray =
      WrapGL(context, &GLContext::fEnableVertexAttribArray);
  i->fFunctions.fFinish = WrapGL(context, &GLContext::fFinish);
  i->fFunctions.fFlush = WrapGL(context, &GLContext::fFlush);
  i->fFunctions.fFramebufferRenderbuffer =
      WrapGL(context, &GLContext::fFramebufferRenderbuffer);
  i->fFunctions.fFramebufferTexture2D =
      WrapGL(context, &GLContext::fFramebufferTexture2D);
  i->fFunctions.fFrontFace = WrapGL(context, &GLContext::fFrontFace);
  i->fFunctions.fGenBuffers = WrapGL(context, &GLContext::fGenBuffers);
  i->fFunctions.fGenFramebuffers =
      WrapGL(context, &GLContext::fGenFramebuffers);
  i->fFunctions.fGenRenderbuffers =
      WrapGL(context, &GLContext::fGenRenderbuffers);
  i->fFunctions.fGetFramebufferAttachmentParameteriv =
      WrapGL(context, &GLContext::fGetFramebufferAttachmentParameteriv);
  i->fFunctions.fGenTextures = WrapGL(context, &GLContext::fGenTextures);
  i->fFunctions.fGenerateMipmap = WrapGL(context, &GLContext::fGenerateMipmap);
  i->fFunctions.fGetBufferParameteriv =
      WrapGL(context, &GLContext::fGetBufferParameteriv);
  i->fFunctions.fGetError = WrapGL(context, &GLContext::fGetError);
  i->fFunctions.fGetIntegerv = getIntegerv;
  i->fFunctions.fGetProgramInfoLog =
      WrapGL(context, &GLContext::fGetProgramInfoLog);
  i->fFunctions.fGetProgramiv = WrapGL(context, &GLContext::fGetProgramiv);
  i->fFunctions.fGetRenderbufferParameteriv =
      WrapGL(context, &GLContext::fGetRenderbufferParameteriv);
  i->fFunctions.fGetShaderInfoLog =
      WrapGL(context, &GLContext::fGetShaderInfoLog);
  i->fFunctions.fGetShaderiv = WrapGL(context, &GLContext::fGetShaderiv);
  i->fFunctions.fGetShaderPrecisionFormat =
      WrapGL(context, &GLContext::fGetShaderPrecisionFormat);
  i->fFunctions.fGetString = getString;
  i->fFunctions.fGetUniformLocation =
      WrapGL(context, &GLContext::fGetUniformLocation);
  i->fFunctions.fIsTexture = WrapGL(context, &GLContext::fIsTexture);
  i->fFunctions.fLineWidth = WrapGL(context, &GLContext::fLineWidth);
  i->fFunctions.fLinkProgram = WrapGL(context, &GLContext::fLinkProgram);
  i->fFunctions.fPixelStorei = WrapGL(context, &GLContext::fPixelStorei);
  i->fFunctions.fPolygonMode = WrapGL(context, &GLContext::fPolygonMode);
  i->fFunctions.fReadPixels = WrapGL(context, &GLContext::fReadPixels);
  i->fFunctions.fRenderbufferStorage =
      WrapGL(context, &GLContext::fRenderbufferStorage);
  i->fFunctions.fScissor = WrapGL(context, &GLContext::fScissor);
  i->fFunctions.fShaderSource = WrapGL(context, &GLContext::fShaderSource);
  i->fFunctions.fStencilFunc = WrapGL(context, &GLContext::fStencilFunc);
  i->fFunctions.fStencilFuncSeparate =
      WrapGL(context, &GLContext::fStencilFuncSeparate);
  i->fFunctions.fStencilMask = WrapGL(context, &GLContext::fStencilMask);
  i->fFunctions.fStencilMaskSeparate =
      WrapGL(context, &GLContext::fStencilMaskSeparate);
  i->fFunctions.fStencilOp = WrapGL(context, &GLContext::fStencilOp);
  i->fFunctions.fStencilOpSeparate =
      WrapGL(context, &GLContext::fStencilOpSeparate);
  i->fFunctions.fTexImage2D = WrapGL(context, &GLContext::fTexImage2D);
  i->fFunctions.fTexParameteri = WrapGL(context, &GLContext::fTexParameteri);
  i->fFunctions.fTexParameteriv = WrapGL(context, &GLContext::fTexParameteriv);
  i->fFunctions.fTexSubImage2D = WrapGL(context, &GLContext::fTexSubImage2D);
  i->fFunctions.fUniform1f = WrapGL(context, &GLContext::fUniform1f);
  i->fFunctions.fUniform1i = WrapGL(context, &GLContext::fUniform1i);
  i->fFunctions.fUniform1fv = WrapGL(context, &GLContext::fUniform1fv);
  i->fFunctions.fUniform1iv = WrapGL(context, &GLContext::fUniform1iv);
  i->fFunctions.fUniform2f = WrapGL(context, &GLContext::fUniform2f);
  i->fFunctions.fUniform2i = WrapGL(context, &GLContext::fUniform2i);
  i->fFunctions.fUniform2fv = WrapGL(context, &GLContext::fUniform2fv);
  i->fFunctions.fUniform2iv = WrapGL(context, &GLContext::fUniform2iv);
  i->fFunctions.fUniform3f = WrapGL(context, &GLContext::fUniform3f);
  i->fFunctions.fUniform3i = WrapGL(context, &GLContext::fUniform3i);
  i->fFunctions.fUniform3fv = WrapGL(context, &GLContext::fUniform3fv);
  i->fFunctions.fUniform3iv = WrapGL(context, &GLContext::fUniform3iv);
  i->fFunctions.fUniform4f = WrapGL(context, &GLContext::fUniform4f);
  i->fFunctions.fUniform4i = WrapGL(context, &GLContext::fUniform4i);
  i->fFunctions.fUniform4fv = WrapGL(context, &GLContext::fUniform4fv);
  i->fFunctions.fUniform4iv = WrapGL(context, &GLContext::fUniform4iv);
  i->fFunctions.fUniformMatrix2fv =
      WrapGL(context, &GLContext::fUniformMatrix2fv);
  i->fFunctions.fUniformMatrix3fv =
      WrapGL(context, &GLContext::fUniformMatrix3fv);
  i->fFunctions.fUniformMatrix4fv =
      WrapGL(context, &GLContext::fUniformMatrix4fv);
  i->fFunctions.fUseProgram = WrapGL(context, &GLContext::fUseProgram);
  i->fFunctions.fVertexAttrib1f = WrapGL(context, &GLContext::fVertexAttrib1f);
  i->fFunctions.fVertexAttrib2fv =
      WrapGL(context, &GLContext::fVertexAttrib2fv);
  i->fFunctions.fVertexAttrib3fv =
      WrapGL(context, &GLContext::fVertexAttrib3fv);
  i->fFunctions.fVertexAttrib4fv =
      WrapGL(context, &GLContext::fVertexAttrib4fv);
  i->fFunctions.fVertexAttribPointer =
      WrapGL(context, &GLContext::fVertexAttribPointer);
  i->fFunctions.fViewport = WrapGL(context, &GLContext::fViewport);

  // Required for either desktop OpenGL 2.0 or OpenGL ES 2.0
  i->fFunctions.fStencilFuncSeparate =
      WrapGL(context, &GLContext::fStencilFuncSeparate);
  i->fFunctions.fStencilMaskSeparate =
      WrapGL(context, &GLContext::fStencilMaskSeparate);
  i->fFunctions.fStencilOpSeparate =
      WrapGL(context, &GLContext::fStencilOpSeparate);

  // GLContext supports glMapBuffer
  i->fFunctions.fMapBuffer = WrapGL(context, &GLContext::fMapBuffer);
  i->fFunctions.fUnmapBuffer = WrapGL(context, &GLContext::fUnmapBuffer);

  // GLContext supports glRenderbufferStorageMultisample/glBlitFramebuffer
  i->fFunctions.fRenderbufferStorageMultisample =
      WrapGL(context, &GLContext::fRenderbufferStorageMultisample);
  i->fFunctions.fBlitFramebuffer =
      WrapGL(context, &GLContext::fBlitFramebuffer);

  // GLContext supports glCompressedTexImage2D
  i->fFunctions.fCompressedTexImage2D =
      WrapGL(context, &GLContext::fCompressedTexImage2D);

  // GL_OES_vertex_array_object
  i->fFunctions.fBindVertexArray =
      WrapGL(context, &GLContext::fBindVertexArray);
  i->fFunctions.fDeleteVertexArrays =
      WrapGL(context, &GLContext::fDeleteVertexArrays);
  i->fFunctions.fGenVertexArrays =
      WrapGL(context, &GLContext::fGenVertexArrays);

  // Desktop GL
  i->fFunctions.fGetTexLevelParameteriv =
      WrapGL(context, &GLContext::fGetTexLevelParameteriv);
  i->fFunctions.fDrawBuffer = WrapGL(context, &GLContext::fDrawBuffer);
  i->fFunctions.fReadBuffer = WrapGL(context, &GLContext::fReadBuffer);

  // Desktop OpenGL > 1.5
  i->fFunctions.fGenQueries = WrapGL(context, &GLContext::fGenQueries);
  i->fFunctions.fDeleteQueries = WrapGL(context, &GLContext::fDeleteQueries);
  i->fFunctions.fBeginQuery = WrapGL(context, &GLContext::fBeginQuery);
  i->fFunctions.fEndQuery = WrapGL(context, &GLContext::fEndQuery);
  i->fFunctions.fGetQueryiv = WrapGL(context, &GLContext::fGetQueryiv);
  i->fFunctions.fGetQueryObjectiv =
      WrapGL(context, &GLContext::fGetQueryObjectiv);
  i->fFunctions.fGetQueryObjectuiv =
      WrapGL(context, &GLContext::fGetQueryObjectuiv);

  // Desktop OpenGL > 2.0
  i->fFunctions.fDrawBuffers = WrapGL(context, &GLContext::fDrawBuffers);

  return i;
}

SkiaGLGlue::SkiaGLGlue(GLContext* context) : mGLContext(context) {
  mGrGLInterface.reset(CreateGrGLInterfaceFromGLContext(mGLContext));
  mGrContext = GrContext::MakeGL(mGrGLInterface);
}

SkiaGLGlue::~SkiaGLGlue() {
  /*
   * These members have inter-dependencies, but do not keep each other alive, so
   * destruction order is very important here: mGrContext uses mGrGLInterface,
   * and through it, uses mGLContext
   */
  mGrContext = nullptr;
  if (mGrGLInterface) {
    // Ensure that no references to the GLContext remain, even if the GrContext
    // still lives.
    mGrGLInterface->fFunctions = GrGLInterface::Functions();
    mGrGLInterface = nullptr;
  }
  mGLContext = nullptr;
}