/*
    Copyright © 2010, 2011, 2012 Vladimír Vondruš <mosra@centrum.cz>

    This file is part of Magnum.

    Magnum is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License version 3
    only, as published by the Free Software Foundation.

    Magnum is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU Lesser General Public License version 3 for more details.
*/

#include "Framebuffer.h"

#include "BufferImage.h"
#include "Context.h"
#include "Extensions.h"
#include "Image.h"
#include "Renderbuffer.h"
#include "Texture.h"

#include "Implementation/State.h"
#include "Implementation/FramebufferState.h"

namespace Magnum {

Framebuffer::RenderbufferImplementation Framebuffer::renderbufferImplementation = &Framebuffer::renderbufferImplementationDefault;
#ifndef MAGNUM_TARGET_GLES
Framebuffer::Texture1DImplementation Framebuffer::texture1DImplementation = &Framebuffer::texture1DImplementationDefault;
#endif
Framebuffer::Texture2DImplementation Framebuffer::texture2DImplementation = &Framebuffer::texture2DImplementationDefault;
Framebuffer::Texture3DImplementation Framebuffer::texture3DImplementation = &Framebuffer::texture3DImplementationDefault;

Framebuffer::Framebuffer(const Vector2i& viewportPosition, const Vector2i& viewportSize) {
    _viewportPosition = viewportPosition;
    _viewportSize = viewportSize;

    glGenFramebuffers(1, &_id);
}

Framebuffer::~Framebuffer() {
    /* If bound, remove itself from state */
    Implementation::FramebufferState* state = Context::current()->state()->framebuffer;
    if(state->readBinding == _id) state->readBinding = 0;
    if(state->drawBinding == _id) state->drawBinding = 0;

    glDeleteFramebuffers(1, &_id);
}

void Framebuffer::mapForDraw(std::initializer_list<std::pair<GLuint, std::int8_t>> attachments) {
    /* Max attachment location */
    std::size_t max = 0;
    for(const auto& attachment: attachments)
        if(attachment.first > max) max = attachment.first;

    /* Create linear array from associative */
    GLenum* _attachments = new GLenum[max+1];
    std::fill_n(_attachments, max, GL_NONE);
    for(const auto& attachment: attachments)
        _attachments[attachment.first] = attachment.second < 0 ? GL_NONE : GL_COLOR_ATTACHMENT0 + attachment.second;

    (this->*drawBuffersImplementation)(max+1, _attachments);
    delete[] _attachments;
}

void Framebuffer::attachTexture2D(DepthStencilAttachment depthStencilAttachment, Texture2D* texture, GLint mipLevel) {
    /** @todo Check for texture target compatibility */
    (this->*texture2DImplementation)(GLenum(depthStencilAttachment), GLenum(texture->target()), texture->id(), mipLevel);
}

void Framebuffer::attachTexture2D(std::uint8_t colorAttachment, Texture2D* texture, GLint mipLevel) {
    /** @todo Check for texture target compatibility */
    (this->*texture2DImplementation)(GL_COLOR_ATTACHMENT0 + colorAttachment, GLenum(texture->target()), texture->id(), mipLevel);
}

void Framebuffer::initializeContextBasedFunctionality(Context* context) {
    #ifndef MAGNUM_TARGET_GLES
    if(context->isExtensionSupported<Extensions::GL::EXT::direct_state_access>()) {
        Debug() << "Framebuffer: using" << Extensions::GL::EXT::direct_state_access::string() << "features";

        renderbufferImplementation = &Framebuffer::renderbufferImplementationDSA;
        texture1DImplementation = &Framebuffer::texture1DImplementationDSA;
        texture2DImplementation = &Framebuffer::texture2DImplementationDSA;
        texture3DImplementation = &Framebuffer::texture3DImplementationDSA;
    }
    #else
    static_cast<void>(context);
    #endif
}

void Framebuffer::renderbufferImplementationDefault(GLenum attachment, Renderbuffer* renderbuffer) {
    glFramebufferRenderbuffer(GLenum(bindInternal()), attachment, GL_RENDERBUFFER, renderbuffer->id());
}

#ifndef MAGNUM_TARGET_GLES
void Framebuffer::renderbufferImplementationDSA(GLenum attachment, Renderbuffer* renderbuffer) {
    glNamedFramebufferRenderbufferEXT(_id, attachment, GL_RENDERBUFFER, renderbuffer->id());
}

void Framebuffer::texture1DImplementationDefault(GLenum attachment, Texture1D* texture, GLint mipLevel) {
    glFramebufferTexture1D(GLenum(bindInternal()), attachment, static_cast<GLenum>(texture->target()), texture->id(), mipLevel);
}

void Framebuffer::texture1DImplementationDSA(GLenum attachment, Texture1D* texture, GLint mipLevel) {
    glNamedFramebufferTexture1DEXT(_id, attachment, GLenum(texture->target()), texture->id(), mipLevel);
}
#endif

void Framebuffer::texture2DImplementationDefault(GLenum attachment, GLenum textureTarget, GLuint textureId, GLint mipLevel) {
    glFramebufferTexture2D(GLenum(bindInternal()), attachment, textureTarget, textureId, mipLevel);
}

#ifndef MAGNUM_TARGET_GLES
void Framebuffer::texture2DImplementationDSA(GLenum attachment, GLenum textureTarget, GLuint textureId, GLint mipLevel) {
    glNamedFramebufferTexture2DEXT(_id, attachment, textureTarget, textureId, mipLevel);
}
#endif

void Framebuffer::texture3DImplementationDefault(GLenum attachment, Texture3D* texture, GLint mipLevel, GLint layer) {
    /** @todo Check for texture target compatibility */
    /** @todo Get some extension wrangler for glFramebufferTexture3D() (extension only) */
    #ifndef MAGNUM_TARGET_GLES
    glFramebufferTexture3D(GLenum(bindInternal()), attachment, static_cast<GLenum>(texture->target()), texture->id(), mipLevel, layer);
    #else
    static_cast<void>(attachment);
    static_cast<void>(texture);
    static_cast<void>(mipLevel);
    static_cast<void>(layer);
    #endif
}

#ifndef MAGNUM_TARGET_GLES
void Framebuffer::texture3DImplementationDSA(GLenum attachment, Texture3D* texture, GLint mipLevel, GLint layer) {
    glNamedFramebufferTexture3DEXT(_id, attachment, GLenum(texture->target()), texture->id(), mipLevel, layer);
}
#endif

}