/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "WebGLExtensions.h"

#include "GLContext.h"
#include "mozilla/dom/WebGLRenderingContextBinding.h"
#include "WebGLContext.h"
#include "WebGLFormats.h"

namespace mozilla {

WebGLExtensionSRGB::WebGLExtensionSRGB(WebGLContext* webgl)
    : WebGLExtensionBase(webgl) {
  MOZ_ASSERT(IsSupported(webgl), "Don't construct extension if unsupported.");

  gl::GLContext* gl = webgl->GL();
  if (!gl->IsGLES()) {
    // Desktop OpenGL requires the following to be enabled in order to
    // support sRGB operations on framebuffers.
    gl->fEnable(LOCAL_GL_FRAMEBUFFER_SRGB_EXT);
  }

  auto& fua = webgl->mFormatUsage;

  RefPtr<gl::GLContext> gl_ = gl;  // Bug 1201275
  const auto fnAdd = [&fua, &gl_](webgl::EffectiveFormat effFormat,
                                  GLenum format, GLenum desktopUnpackFormat) {
    auto usage = fua->EditUsage(effFormat);
    usage->isFilterable = true;

    webgl::DriverUnpackInfo dui = {format, format, LOCAL_GL_UNSIGNED_BYTE};
    const auto pi = dui.ToPacking();

    if (!gl_->IsGLES()) dui.unpackFormat = desktopUnpackFormat;

    fua->AddTexUnpack(usage, pi, dui);

    fua->AllowUnsizedTexFormat(pi, usage);
  };

  fnAdd(webgl::EffectiveFormat::SRGB8, LOCAL_GL_SRGB, LOCAL_GL_RGB);
  fnAdd(webgl::EffectiveFormat::SRGB8_ALPHA8, LOCAL_GL_SRGB_ALPHA,
        LOCAL_GL_RGBA);

  auto usage = fua->EditUsage(webgl::EffectiveFormat::SRGB8_ALPHA8);
  usage->SetRenderable();
  fua->AllowRBFormat(LOCAL_GL_SRGB8_ALPHA8, usage);
}

bool WebGLExtensionSRGB::IsSupported(const WebGLContext* const webgl) {
  if (webgl->IsWebGL2()) return false;

  return webgl->gl->IsSupported(gl::GLFeature::sRGB);
}

}  // namespace mozilla