/* 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 {

WebGLExtensionTextureHalfFloat::WebGLExtensionTextureHalfFloat(WebGLContext* webgl)

    : WebGLExtensionBase(webgl)

{

    auto& fua = webgl->mFormatUsage;

    gl::GLContext* gl = webgl->GL();

    webgl::PackingInfo pi;

    webgl::DriverUnpackInfo dui;

    const GLint* swizzle = nullptr;

    const auto fnAdd = [&fua, &pi, &dui, &swizzle](webgl::EffectiveFormat effFormat)

    {

        auto usage = fua->EditUsage(effFormat);

        usage->textureSwizzleRGBA = swizzle;

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

        fua->AllowUnsizedTexFormat(pi, usage);

    };

    const bool needsSwizzle = gl->IsCoreProfile();

    MOZ_ASSERT_IF(needsSwizzle, gl->IsSupported(gl::GLFeature::texture_swizzle));

    const bool needsSizedFormat = !gl->IsGLES();

    GLenum driverUnpackType = LOCAL_GL_HALF_FLOAT;

    if (!gl->IsSupported(gl::GLFeature::texture_half_float)) {

        MOZ_ASSERT(gl->IsExtensionSupported(gl::GLContext::OES_texture_half_float));

        driverUnpackType = LOCAL_GL_HALF_FLOAT_OES;

    }

    ////////////////

    pi = {LOCAL_GL_RGBA, LOCAL_GL_HALF_FLOAT_OES};

    dui = {pi.format, pi.format, driverUnpackType};

    swizzle = nullptr;

    if (needsSizedFormat) {

        dui.internalFormat = LOCAL_GL_RGBA16F;

    }

    fnAdd(webgl::EffectiveFormat::RGBA16F);

    //////

    pi = {LOCAL_GL_RGB, LOCAL_GL_HALF_FLOAT_OES};

    dui = {pi.format, pi.format, driverUnpackType};

    swizzle = nullptr;

    if (needsSizedFormat) {

        dui.internalFormat = LOCAL_GL_RGB16F;

    }

    fnAdd(webgl::EffectiveFormat::RGB16F);

    //////

    pi = {LOCAL_GL_LUMINANCE, LOCAL_GL_HALF_FLOAT_OES};

    dui = {pi.format, pi.format, driverUnpackType};

    swizzle = nullptr;

    if (needsSwizzle) {

        dui = {LOCAL_GL_R16F, LOCAL_GL_RED, driverUnpackType};

        swizzle = webgl::FormatUsageInfo::kLuminanceSwizzleRGBA;

    } else if (needsSizedFormat) {

        dui.internalFormat = LOCAL_GL_LUMINANCE16F_ARB;

    }

    fnAdd(webgl::EffectiveFormat::Luminance16F);

    //////

    pi = {LOCAL_GL_ALPHA, LOCAL_GL_HALF_FLOAT_OES};

    dui = {pi.format, pi.format, driverUnpackType};

    swizzle = nullptr;

    if (needsSwizzle) {

        dui = {LOCAL_GL_R16F, LOCAL_GL_RED, driverUnpackType};

        swizzle = webgl::FormatUsageInfo::kAlphaSwizzleRGBA;

    } else if (needsSizedFormat) {

        dui.internalFormat = LOCAL_GL_ALPHA16F_ARB;

    }

    fnAdd(webgl::EffectiveFormat::Alpha16F);

    //////

    pi = {LOCAL_GL_LUMINANCE_ALPHA, LOCAL_GL_HALF_FLOAT_OES};

    dui = {pi.format, pi.format, driverUnpackType};

    swizzle = nullptr;

    if (needsSwizzle) {

        dui = {LOCAL_GL_RG16F, LOCAL_GL_RG, driverUnpackType};

        swizzle = webgl::FormatUsageInfo::kLumAlphaSwizzleRGBA;

    } else if (needsSizedFormat) {

        dui.internalFormat = LOCAL_GL_LUMINANCE_ALPHA16F_ARB;

    }

    fnAdd(webgl::EffectiveFormat::Luminance16FAlpha16F);

}

WebGLExtensionTextureHalfFloat::~WebGLExtensionTextureHalfFloat()

{

}

bool

WebGLExtensionTextureHalfFloat::IsSupported(const WebGLContext* webgl)

{

    gl::GLContext* gl = webgl->GL();

    if (!gl->IsSupported(gl::GLFeature::texture_half_float) &&

        !gl->IsExtensionSupported(gl::GLContext::OES_texture_half_float))

    {

        return false;

    }

    const bool needsSwizzle = gl->IsCoreProfile();

    const bool hasSwizzle = gl->IsSupported(gl::GLFeature::texture_swizzle);

    if (needsSwizzle && !hasSwizzle)

        return false;

    return true;

}

IMPL_WEBGL_EXTENSION_GOOP(WebGLExtensionTextureHalfFloat, OES_texture_half_float)

} // namespace mozilla