/*

 *  The Mana World

 *  Copyright (C) 2004  The Mana World Development Team

 *

 *  This file is part of The Mana World.

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  any later version.

 *

 *  This program 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 General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#include <SDL.h>

#include "log.h"

#include "openglgraphics.h"

#include "resources/image.h"

#ifdef USE_OPENGL

#ifdef __APPLE__

#include <OpenGL/OpenGL.h>

#endif

#ifndef GL_TEXTURE_RECTANGLE_ARB

#define GL_TEXTURE_RECTANGLE_ARB 0x84F5

#define GL_MAX_RECTANGLE_TEXTURE_SIZE_ARB 0x84F8

#endif

OpenGLGraphics::OpenGLGraphics():

    mAlpha(false), mTexture(false), mColorAlpha(false),

    mSync(false)

{

}

OpenGLGraphics::~OpenGLGraphics()

{

}

void OpenGLGraphics::setSync(bool sync)

{

    mSync = sync;

}

bool OpenGLGraphics::setVideoMode(int w, int h, int bpp, bool fs, bool hwaccel)

{

    logger->log("Setting video mode %dx%d %s",

            w, h, fs ? "fullscreen" : "windowed");

    int displayFlags = SDL_ANYFORMAT | SDL_OPENGL;

    mFullscreen = fs;

    mHWAccel = hwaccel;

    if (fs)

        displayFlags |= SDL_FULLSCREEN;

    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);

    if (!(mScreen = SDL_SetVideoMode(w, h, bpp, displayFlags)))

        return false;

#ifdef __APPLE__

    if (mSync)

    {

        const GLint VBL = 1;

        CGLSetParameter(CGLGetCurrentContext(), kCGLCPSwapInterval, &VBL);

    }

#endif

    // Setup OpenGL

    glViewport(0, 0, w, h);

    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);

    int gotDoubleBuffer;

    SDL_GL_GetAttribute(SDL_GL_DOUBLEBUFFER, &gotDoubleBuffer);

    logger->log("Using OpenGL %s double buffering.",

            (gotDoubleBuffer ? "with" : "without"));

    char const *glExtensions = (char const *)glGetString(GL_EXTENSIONS);

    GLint texSize;

    bool rectTex = strstr(glExtensions, "GL_ARB_texture_rectangle");

    if (rectTex)

    {

        Image::mTextureType = GL_TEXTURE_RECTANGLE_ARB;

        glGetIntegerv(GL_MAX_RECTANGLE_TEXTURE_SIZE_ARB, &texSize);

    }

    else

    {

        Image::mTextureType = GL_TEXTURE_2D;

        glGetIntegerv(GL_MAX_TEXTURE_SIZE, &texSize);

    }

    Image::mTextureSize = texSize;

    logger->log("OpenGL texture size: %d pixels%s", Image::mTextureSize,

                rectTex ? " (rectangle textures)" : "");

    return true;

}

static inline void drawQuad(Image *image,

                            int srcX, int srcY, int dstX, int dstY,

                            int width, int height)

{

    if (image->getTextureType() == GL_TEXTURE_2D)

    {

        // Find OpenGL normalized texture coordinates.

        float texX1 = srcX / (float) image->getTextureWidth();

        float texY1 = srcY / (float) image->getTextureHeight();

        float texX2 = (srcX + width) / (float) image->getTextureWidth();

        float texY2 = (srcY + height) / (float) image->getTextureHeight();

        glTexCoord2f(texX1, texY1);

        glVertex2i(dstX, dstY);

        glTexCoord2f(texX2, texY1);

        glVertex2i(dstX + width, dstY);

        glTexCoord2f(texX2, texY2);

        glVertex2i(dstX + width, dstY + height);

        glTexCoord2f(texX1, texY2);

        glVertex2i(dstX, dstY + height);

    }

    else

    {

        glTexCoord2i(srcX, srcY);

        glVertex2i(dstX, dstY);

        glTexCoord2i(srcX + width, srcY);

        glVertex2i(dstX + width, dstY);

        glTexCoord2i(srcX + width, srcY + height);

        glVertex2i(dstX + width, dstY + height);

        glTexCoord2i(srcX, srcY + height);

        glVertex2i(dstX, dstY + height);

    }

}

static inline void drawRescaledQuad(Image *image,

                            int srcX, int srcY, int dstX, int dstY,

                            int width, int height,

                            int desiredWidth, int desiredHeight)

{

    if (image->getTextureType() == GL_TEXTURE_2D)

    {

        // Find OpenGL normalized texture coordinates.

        float texX1 = srcX / (float) image->getTextureWidth();

        float texY1 = srcY / (float) image->getTextureHeight();

        float texX2 = (srcX + width) / (float) image->getTextureWidth();

        float texY2 = (srcY + height) / (float) image->getTextureHeight();

        glTexCoord2f(texX1, texY1);

        glVertex2i(dstX, dstY);

        glTexCoord2f(texX2, texY1);

        glVertex2i(dstX + desiredWidth, dstY);

        glTexCoord2f(texX2, texY2);

        glVertex2i(dstX + desiredWidth, dstY + desiredHeight);

        glTexCoord2f(texX1, texY2);

        glVertex2i(dstX, dstY + desiredHeight);

    }

    else

    {

        glTexCoord2i(srcX, srcY);

        glVertex2i(dstX, dstY);

        glTexCoord2i(srcX + width, srcY);

        glVertex2i(dstX + desiredWidth, dstY);

        glTexCoord2i(srcX + width, srcY + height);

        glVertex2i(dstX + desiredWidth, dstY + desiredHeight);

        glTexCoord2i(srcX, srcY + height);

        glVertex2i(dstX, dstY + desiredHeight);

    }

}

bool OpenGLGraphics::drawImage(Image *image, int srcX, int srcY,

                               int dstX, int dstY,

                               int width, int height, bool useColor)

{

    if (!image)

        return false;

    srcX += image->mBounds.x;

    srcY += image->mBounds.y;

    if (!useColor)

        glColor4f(1.0f, 1.0f, 1.0f, image->mAlpha);

    glBindTexture(Image::mTextureType, image->mGLImage);

    setTexturingAndBlending(true);

    // Draw a textured quad.

    glBegin(GL_QUADS);

    drawQuad(image, srcX, srcY, dstX, dstY, width, height);

    glEnd();

    if (!useColor)

        glColor4ub(mColor.r, mColor.g, mColor.b, mColor.a);

    return true;

}

bool OpenGLGraphics::drawRescaledImage(Image *image, int srcX, int srcY,

                               int dstX, int dstY,

                               int width, int height,

                               int desiredWidth, int desiredHeight,

                               bool useColor)

{

    return drawRescaledImage(image, srcX, srcY,

                             dstX, dstY,

                             width, height,

                             desiredWidth, desiredHeight,

                             useColor, true);

}

bool OpenGLGraphics::drawRescaledImage(Image *image, int srcX, int srcY,

                               int dstX, int dstY,

                               int width, int height,

                               int desiredWidth, int desiredHeight,

                               bool useColor, bool smooth)

{

    if (!image)

        return false;

    // Just draw the image normally when no resizing is necessary,

    if (width == desiredWidth && height == desiredHeight)

        return drawImage(image, srcX, srcY, dstX, dstY, width, height, useColor);

    // When the desired image is smaller than the current one,

    // disable smooth effect.

    if (width > desiredWidth && height > desiredHeight)

        smooth = false;

    srcX += image->mBounds.x;

    srcY += image->mBounds.y;

    if (!useColor)

        glColor4f(1.0f, 1.0f, 1.0f, image->mAlpha);

    glBindTexture(Image::mTextureType, image->mGLImage);

    setTexturingAndBlending(true);

    // Draw a textured quad.

    glBegin(GL_QUADS);

    drawRescaledQuad(image, srcX, srcY, dstX, dstY, width, height,

                     desiredWidth, desiredHeight);

    if (smooth) // A basic smooth effect...

    {

        glColor4f(1.0f, 1.0f, 1.0f, 0.2f);

        drawRescaledQuad(image, srcX, srcY, dstX - 1, dstY - 1, width, height,

                        desiredWidth + 1, desiredHeight + 1);

        drawRescaledQuad(image, srcX, srcY, dstX + 1, dstY + 1, width, height,

                        desiredWidth - 1, desiredHeight - 1);

        drawRescaledQuad(image, srcX, srcY, dstX + 1, dstY, width, height,

                        desiredWidth - 1, desiredHeight);

        drawRescaledQuad(image, srcX, srcY, dstX, dstY + 1, width, height,

                        desiredWidth, desiredHeight - 1);

    }

    glEnd();

    if (!useColor)

        glColor4ub(mColor.r, mColor.g, mColor.b, mColor.a);

    return true;

}

/* Optimising the functions that Graphics::drawImagePattern would call,

 * so that glBegin...glEnd are outside the main loop. */

void OpenGLGraphics::drawImagePattern(Image *image, int x, int y, int w, int h)

{

    if (!image)

        return;

    const int srcX = image->mBounds.x;

    const int srcY = image->mBounds.y;

    const int iw = image->getWidth();

    const int ih = image->getHeight();

    if (iw == 0 || ih == 0)

        return;

    glColor4f(1.0f, 1.0f, 1.0f, image->mAlpha);

    glBindTexture(Image::mTextureType, image->mGLImage);

    setTexturingAndBlending(true);

    // Draw a set of textured rectangles

    glBegin(GL_QUADS);

    for (int py = 0; py < h; py += ih)

    {

        const int height = (py + ih >= h) ? h - py : ih;

        const int dstY = y + py;

        for (int px = 0; px < w; px += iw)

        {

            int width = (px + iw >= w) ? w - px : iw;

            int dstX = x + px;

            drawQuad(image, srcX, srcY, dstX, dstY, width, height);

        }

    }

    glEnd();

    glColor4ub(mColor.r, mColor.g, mColor.b, mColor.a);

}

void OpenGLGraphics::drawRescaledImagePattern(Image *image, int x, int y,

                                      int w, int h,

                                      int scaledWidth, int scaledHeight)

{

    if (!image)

        return;

    const int srcX = image->mBounds.x;

    const int srcY = image->mBounds.y;

    const int iw = scaledWidth;

    const int ih = scaledHeight;

    if (iw == 0 || ih == 0)

        return;

    glColor4f(1.0f, 1.0f, 1.0f, image->mAlpha);

    glBindTexture(Image::mTextureType, image->mGLImage);

    setTexturingAndBlending(true);

    // Draw a set of textured rectangles

    glBegin(GL_QUADS);

    for (int py = 0; py < h; py += ih)

    {

        const int height = (py + ih >= h) ? h - py : ih;

        const int dstY = y + py;

        for (int px = 0; px < w; px += iw)

        {

            int width = (px + iw >= w) ? w - px : iw;

            int dstX = x + px;

            drawRescaledQuad(image, srcX, srcY, dstX, dstY,

                             width, height, scaledWidth, scaledHeight);

        }

    }

    glEnd();

    glColor4ub(mColor.r, mColor.g, mColor.b, mColor.a);

}

void OpenGLGraphics::updateScreen()

{

    glFlush();

    glFinish();

    SDL_GL_SwapBuffers();

}

void OpenGLGraphics::_beginDraw()

{

    glMatrixMode(GL_TEXTURE);

    glLoadIdentity();

    glMatrixMode(GL_PROJECTION);

    glLoadIdentity();

    glOrtho(0.0, (double)mScreen->w, (double)mScreen->h, 0.0, -1.0, 1.0);

    glMatrixMode(GL_MODELVIEW);

    glLoadIdentity();

    glEnable(GL_SCISSOR_TEST);

    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    pushClipArea(gcn::Rectangle(0, 0, mScreen->w, mScreen->h));

}

void OpenGLGraphics::_endDraw()

{

}

SDL_Surface* OpenGLGraphics::getScreenshot()

{

    int h = mScreen->h;

    int w = mScreen->w;

    SDL_Surface *screenshot = SDL_CreateRGBSurface(

            SDL_SWSURFACE,

            w, h, 24,

            0xff0000, 0x00ff00, 0x0000ff, 0x000000);

    if (SDL_MUSTLOCK(screenshot))

        SDL_LockSurface(screenshot);

    // Grap the pixel buffer and write it to the SDL surface

    glPixelStorei(GL_PACK_ALIGNMENT, 1);

    glReadPixels(0, 0, w, h, GL_RGB, GL_UNSIGNED_BYTE, screenshot->pixels);

    // Flip the screenshot, as OpenGL has 0,0 in bottom left

    unsigned int lineSize = 3 * w;

    GLubyte* buf = (GLubyte*)malloc(lineSize);

    for (int i = 0; i < (h / 2); i++)

    {

        GLubyte *top = (GLubyte*)screenshot->pixels + lineSize * i;

        GLubyte *bot = (GLubyte*)screenshot->pixels + lineSize * (h - 1 - i);

        memcpy(buf, top, lineSize);

        memcpy(top, bot, lineSize);

        memcpy(bot, buf, lineSize);

    }

    free(buf);

    if (SDL_MUSTLOCK(screenshot))

        SDL_UnlockSurface(screenshot);

    return screenshot;

}

bool OpenGLGraphics::pushClipArea(gcn::Rectangle area)

{

    int transX = 0;

    int transY = 0;

    if (!mClipStack.empty())

    {

        transX = -mClipStack.top().xOffset;

        transY = -mClipStack.top().yOffset;

    }

    bool result = gcn::Graphics::pushClipArea(area);

    transX += mClipStack.top().xOffset;

    transY += mClipStack.top().yOffset;

    glPushMatrix();

    glTranslatef(transX, transY, 0);

    glScissor(mClipStack.top().x,

            mScreen->h - mClipStack.top().y - mClipStack.top().height,

            mClipStack.top().width,

            mClipStack.top().height);

    return result;

}

void OpenGLGraphics::popClipArea()

{

    gcn::Graphics::popClipArea();

    if (mClipStack.empty())

        return;

    glPopMatrix();

    glScissor(mClipStack.top().x,

              mScreen->h - mClipStack.top().y - mClipStack.top().height,

              mClipStack.top().width,

              mClipStack.top().height);

}

void OpenGLGraphics::setColor(const gcn::Color& color)

{

    mColor = color;

    glColor4ub(color.r, color.g, color.b, color.a);

    mColorAlpha = (color.a != 255);

}

void OpenGLGraphics::drawPoint(int x, int y)

{

    setTexturingAndBlending(false);

    glBegin(GL_POINTS);

    glVertex2i(x, y);

    glEnd();

}

void OpenGLGraphics::drawLine(int x1, int y1, int x2, int y2)

{

    setTexturingAndBlending(false);

    glBegin(GL_LINES);

    glVertex2f(x1 + 0.5f, y1 + 0.5f);

    glVertex2f(x2 + 0.5f, y2 + 0.5f);

    glEnd();

    glBegin(GL_POINTS);

    glVertex2f(x2 + 0.5f, y2 + 0.5f);

    glEnd();

}

void OpenGLGraphics::drawRectangle(const gcn::Rectangle& rect)

{

    drawRectangle(rect, false);

}

void OpenGLGraphics::fillRectangle(const gcn::Rectangle& rect)

{

    drawRectangle(rect, true);

}

void OpenGLGraphics::setTargetPlane(int width, int height)

{

}

void OpenGLGraphics::setTexturingAndBlending(bool enable)

{

    if (enable)

    {

        if (!mTexture)

        {

            glEnable(Image::mTextureType);

            mTexture = true;

        }

        if (!mAlpha)

        {

            glEnable(GL_BLEND);

            mAlpha = true;

        }

    }

    else

    {

        if (mAlpha && !mColorAlpha)

        {

            glDisable(GL_BLEND);

            mAlpha = false;

        }

        else if (!mAlpha && mColorAlpha)

        {

            glEnable(GL_BLEND);

            mAlpha = true;

        }

        if (mTexture)

        {

            glDisable(Image::mTextureType);

            mTexture = false;

        }

    }

}

void OpenGLGraphics::drawRectangle(const gcn::Rectangle& rect, bool filled)

{

    const float offset = filled ? 0 : 0.5f;

    setTexturingAndBlending(false);

    glBegin(filled ? GL_QUADS : GL_LINE_LOOP);

    glVertex2f(rect.x + offset, rect.y + offset);

    glVertex2f(rect.x + rect.width - offset, rect.y + offset);

    glVertex2f(rect.x + rect.width - offset, rect.y + rect.height - offset);

    glVertex2f(rect.x + offset, rect.y + rect.height - offset);

    glEnd();

}

#endif // USE_OPENGL