/* -*- 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"

namespace mozilla {

WebGLExtensionDepthTexture::WebGLExtensionDepthTexture(
    WebGLContext* const webgl)
    : WebGLExtensionBase(webgl) {
  auto& fua = webgl->mFormatUsage;

  const auto fnAdd = [&fua](webgl::EffectiveFormat effFormat,
                            GLenum unpackFormat, GLenum unpackType) {
    auto usage = fua->EditUsage(effFormat);
    MOZ_ASSERT(usage->isFilterable);
    MOZ_ASSERT(usage->IsRenderable());

    const webgl::PackingInfo pi = {unpackFormat, unpackType};
    const webgl::DriverUnpackInfo dui = {unpackFormat, unpackFormat,
                                         unpackType};
    fua->AddTexUnpack(usage, pi, dui);
    fua->AllowUnsizedTexFormat(pi, usage);
  };

  fnAdd(webgl::EffectiveFormat::DEPTH_COMPONENT16, LOCAL_GL_DEPTH_COMPONENT,
        LOCAL_GL_UNSIGNED_SHORT);
  fnAdd(webgl::EffectiveFormat::DEPTH_COMPONENT24, LOCAL_GL_DEPTH_COMPONENT,
        LOCAL_GL_UNSIGNED_INT);
  fnAdd(webgl::EffectiveFormat::DEPTH24_STENCIL8, LOCAL_GL_DEPTH_STENCIL,
        LOCAL_GL_UNSIGNED_INT_24_8);
}

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

  // WEBGL_depth_texture supports DEPTH_STENCIL textures
  const auto& gl = webgl->gl;
  if (!gl->IsSupported(gl::GLFeature::packed_depth_stencil)) return false;

  return gl->IsSupported(gl::GLFeature::depth_texture) ||
         gl->IsExtensionSupported(gl::GLContext::ANGLE_depth_texture);
}

}  // namespace mozilla