/*      _______   __   __   __   ______   __   __   _______   __   __
 *     / _____/\ / /\ / /\ / /\ / ____/\ / /\ / /\ / ___  /\ /  |\/ /\
 *    / /\____\// / // / // / // /\___\// /_// / // /\_/ / // , |/ / /
 *   / / /__   / / // / // / // / /    / ___  / // ___  / // /| ' / /
 *  / /_// /\ / /_// / // / // /_/_   / / // / // /\_/ / // / |  / /
 * /______/ //______/ //_/ //_____/\ /_/ //_/ //_/ //_/ //_/ /|_/ /
 * \______\/ \______\/ \_\/ \_____\/ \_\/ \_\/ \_\/ \_\/ \_\/ \_\/
 *
 * Copyright (c) 2004, 2005, 2006, 2007 Olof Naessén and Per Larsson
 *
 *                                                         Js_./
 * Per Larsson a.k.a finalman                          _RqZ{a<^_aa
 * Olof Naessén a.k.a jansem/yakslem                _asww7!uY`>  )\a//
 *                                                 _Qhm`] _f "'c  1!5m
 * Visit: http://guichan.darkbits.org             )Qk<P ` _: :+' .'  "{[
 *                                               .)j(] .d_/ '-(  P .   S
 * License: (BSD)                                <Td/Z <fP"5(\"??"\a.  .L
 * Redistribution and use in source and          _dV>ws?a-?'      ._/L  #'
 * binary forms, with or without                 )4d[#7r, .   '     )d`)[
 * modification, are permitted provided         _Q-5'5W..j/?'   -?!\)cam'
 * that the following conditions are met:       j<<WP+k/);.        _W=j f
 * 1. Redistributions of source code must       .$%w\/]Q  . ."'  .  mj$
 *    retain the above copyright notice,        ]E.pYY(Q]>.   a     J@\
 *    this list of conditions and the           j(]1u<sE"L,. .   ./^ ]{a
 *    following disclaimer.                     4'_uomm\.  )L);-4     (3=
 * 2. Redistributions in binary form must        )_]X{Z('a_"a7'<a"a,  ]"[
 *    reproduce the above copyright notice,       #}<]m7`Za??4,P-"'7. ).m
 *    this list of conditions and the            ]d2e)Q(<Q(  ?94   b-  LQ/
 *    following disclaimer in the                <B!</]C)d_, '(<' .f. =C+m
 *    documentation and/or other materials      .Z!=J ]e []('-4f _ ) -.)m]'
 *    provided with the distribution.          .w[5]' _[ /.)_-"+?   _/ <W"
 * 3. Neither the name of Guichan nor the      :$we` _! + _/ .        j?
 *    names of its contributors may be used     =3)= _f  (_yQmWW$#(    "
 *    to endorse or promote products derived     -   W,  sQQQQmZQ#Wwa]..
 *    from this software without specific        (js, \[QQW$QWW#?!V"".
 *    prior written permission.                    ]y:.<\..          .
 *                                                 -]n w/ '         [.
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT       )/ )/           !
 * HOLDERS AND CONTRIBUTORS "AS IS" AND ANY         <  (; sac    ,    '
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING,               ]^ .-  %
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF            c <   r
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR            aga<  <La
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE          5%  )P'-3L
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR        _bQf` y`..)a
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,          ,J?4P'.P"_(\?d'.,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES               _Pa,)!f/<[]/  ?"
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT      _2-..:. .r+_,.. .
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,     ?a.<%"'  " -'.a_ _,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION)                     ^
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * For comments regarding functions please see the header file.
 */

#include "guisan/sdl/sdlgraphics.hpp"

#include "guisan/exception.hpp"
#include "guisan/font.hpp"
#include "guisan/image.hpp"
#include "guisan/sdl/sdlimage.hpp"
#include "guisan/sdl/sdlpixel.hpp"

// For some reason an old version of MSVC did not like std::abs,
// so we added this macro.
#ifndef ABS
# define ABS(x) ((x) < 0 ? -(x) : (x))
#endif

namespace gcn
{

    SDLGraphics::~SDLGraphics()
    {}

    void SDLGraphics::_beginDraw()
    {
        Rectangle area;
        area.x = 0;
        area.y = 0;
        area.width = mTarget->w;
        area.height = mTarget->h;
        pushClipArea(area);
    }

    void SDLGraphics::_endDraw()
    {
        popClipArea();
    }

    void SDLGraphics::setTarget(SDL_Surface* target)
    {
        mTarget = target;
    }

    bool SDLGraphics::pushClipArea(Rectangle area)
    {
        SDL_Rect rect;
        const bool result = Graphics::pushClipArea(area);

        const ClipRectangle& carea = mClipStack.top();
        rect.x = carea.x;
        rect.y = carea.y;
        rect.w = carea.width;
        rect.h = carea.height;

        SDL_SetClipRect(mTarget, &rect);

        return result;
    }

    void SDLGraphics::popClipArea()
    {
        Graphics::popClipArea();

        if (mClipStack.empty())
        {
            return;
        }

        const ClipRectangle& carea = mClipStack.top();
        SDL_Rect rect;
        rect.x = carea.x;
        rect.y = carea.y;
        rect.w = carea.width;
        rect.h = carea.height;

        SDL_SetClipRect(mTarget, &rect);
    }

    SDL_Surface* SDLGraphics::getTarget() const
    {
        return mTarget;
    }

    void SDLGraphics::drawImage(
        const Image* image, int srcX, int srcY, int dstX, int dstY, int width, int height)
    {
        if (mClipStack.empty())
        {
            throw GCN_EXCEPTION("Clip stack is empty, perhaps you"
                                "called a draw function outside of _beginDraw() and _endDraw()?");
        }

        const ClipRectangle& top = mClipStack.top();
        SDL_Rect src;
        SDL_Rect dst;
        src.x = srcX;
        src.y = srcY;
        src.w = width;
        src.h = height;
        dst.x = dstX + top.xOffset;
        dst.y = dstY + top.yOffset;

        const SDLImage* srcImage = dynamic_cast<const SDLImage*>(image);

        if (srcImage == nullptr)
        {
            throw GCN_EXCEPTION("Trying to draw an image of unknown format, must be an SDLImage.");
        }

        SDL_BlitSurface(srcImage->getSurface(), &src, mTarget, &dst);
    }

    void SDLGraphics::fillRectangle(const Rectangle& rectangle)
    {
        if (mClipStack.empty())
        {
            throw GCN_EXCEPTION("Clip stack is empty, perhaps you"
                                "called a draw function outside of _beginDraw() and _endDraw()?");
        }

        const ClipRectangle& top = mClipStack.top();

        Rectangle area = rectangle;
        area.x += top.xOffset;
        area.y += top.yOffset;

        if (!area.isIntersecting(top))
        {
            return;
        }

        if (mAlpha)
        {
            const int x1 = area.x > top.x ? area.x : top.x;
            const int y1 = area.y > top.y ? area.y : top.y;
            const int x2 =
                area.x + area.width < top.x + top.width ? area.x + area.width : top.x + top.width;
            const int y2 = area.y + area.height < top.y + top.height ? area.y + area.height
                                                                     : top.y + top.height;

            SDL_LockSurface(mTarget);
            for (int y = y1; y < y2; y++)
            {
                for (int x = x1; x < x2; x++)
                {
                    SDLputPixelAlpha(mTarget, x, y, mColor);
                }
            }
            SDL_UnlockSurface(mTarget);
        }
        else
        {
            SDL_Rect rect;
            rect.x = area.x;
            rect.y = area.y;
            rect.w = area.width;
            rect.h = area.height;

            const Uint32 color =
                SDL_MapRGBA(mTarget->format, mColor.r, mColor.g, mColor.b, mColor.a);
            SDL_FillRect(mTarget, &rect, color);
        }
    }

    void SDLGraphics::drawPoint(int x, int y)
    {
        if (mClipStack.empty())
        {
            throw GCN_EXCEPTION("Clip stack is empty, perhaps you"
                                "called a draw function outside of _beginDraw() and _endDraw()?");
        }

        const ClipRectangle& top = mClipStack.top();

        x += top.xOffset;
        y += top.yOffset;

        if (!top.isContaining(x, y))
        {
            return;
        }

        if (mAlpha)
        {
            SDLputPixelAlpha(mTarget, x, y, mColor);
        }
        else
        {
            SDLputPixel(mTarget, x, y, mColor);
        }
    }

    void SDLGraphics::drawHLine(int x1, int y, int x2)
    {
        if (mClipStack.empty())
        {
            throw GCN_EXCEPTION("Clip stack is empty, perhaps you"
                                "called a draw function outside of _beginDraw() and _endDraw()?");
        }
        const ClipRectangle& top = mClipStack.top();

        x1 += top.xOffset;
        y += top.yOffset;
        x2 += top.xOffset;

        if (y < top.y || y >= top.y + top.height)
        {
            return;
        }

        if (x1 > x2)
        {
            x1 ^= x2;
            x2 ^= x1;
            x1 ^= x2;
        }

        if (top.x > x1)
        {
            if (top.x > x2)
            {
                return;
            }
            x1 = top.x;
        }

        if (top.x + top.width <= x2)
        {
            if (top.x + top.width <= x1)
            {
                return;
            }
            x2 = top.x + top.width - 1;
        }

        const int bpp = mTarget->format->BytesPerPixel;

        SDL_LockSurface(mTarget);

        Uint8* p = reinterpret_cast<Uint8*>(mTarget->pixels) + y * mTarget->pitch + x1 * bpp;

        Uint32 pixel = SDL_MapRGB(mTarget->format, mColor.r, mColor.g, mColor.b);

        switch (bpp)
        {
            case 1:
            {
                for (; x1 <= x2; ++x1)
                {
                    *(p++) = pixel;
                }
            }
            break;

            case 2:
            {
                Uint16* q = reinterpret_cast<Uint16*>(p);
                for (; x1 <= x2; ++x1)
                {
                    *(q++) = pixel;
                }
            }
            break;

            case 3:
            {
#if (SDL_BYTEORDER == SDL_BIG_ENDIAN)
                for (; x1 <= x2; ++x1)
                {
                    p[0] = (pixel >> 16) & 0xff;
                    p[1] = (pixel >> 8) & 0xff;
                    p[2] = pixel & 0xff;
                    p += 3;
                }
#else
                for (; x1 <= x2; ++x1)
                {
                    p[0] = pixel & 0xff;
                    p[1] = (pixel >> 8) & 0xff;
                    p[2] = (pixel >> 16) & 0xff;
                    p += 3;
                }
#endif
            }
            break;

            case 4:
            {
                Uint32* q = reinterpret_cast<Uint32*>(p);
                for (; x1 <= x2; ++x1)
                {
                    if (mAlpha)
                    {
                        *q = SDLAlpha32(pixel, *q, mColor.a);
                        q++;
                    }
                    else
                    {
                        *(q++) = pixel;
                    }
                }
            }
            break;

        } // end switch

        SDL_UnlockSurface(mTarget);
    }

    void SDLGraphics::drawVLine(int x, int y1, int y2)
    {
        if (mClipStack.empty())
        {
            throw GCN_EXCEPTION("Clip stack is empty, perhaps you"
                                "called a draw function outside of _beginDraw() and _endDraw()?");
        }
        const ClipRectangle& top = mClipStack.top();

        x += top.xOffset;
        y1 += top.yOffset;
        y2 += top.yOffset;

        if (x < top.x || x >= top.x + top.width)
        {
            return;
        }

        if (y1 > y2)
        {
            y1 ^= y2;
            y2 ^= y1;
            y1 ^= y2;
        }

        if (top.y > y1)
        {
            if (top.y > y2)
            {
                return;
            }
            y1 = top.y;
        }

        if (top.y + top.height <= y2)
        {
            if (top.y + top.height <= y1)
            {
                return;
            }
            y2 = top.y + top.height - 1;
        }

        const int bpp = mTarget->format->BytesPerPixel;

        SDL_LockSurface(mTarget);

        Uint8* p = reinterpret_cast<Uint8*>(mTarget->pixels) + y1 * mTarget->pitch + x * bpp;

        Uint32 pixel = SDL_MapRGB(mTarget->format, mColor.r, mColor.g, mColor.b);

        switch (bpp)
        {
            case 1:
            {
                for (; y1 <= y2; ++y1)
                {
                    *p = pixel;
                    p += mTarget->pitch;
                }
            }
            break;

            case 2:
            {
                for (; y1 <= y2; ++y1)
                {
                    *reinterpret_cast<Uint16*>(p) = pixel;
                    p += mTarget->pitch;
                }
            }
            break;

            case 3:
            {
#if (SDL_BYTEORDER == SDL_BIG_ENDIAN)
                for (; y1 <= y2; ++y1)
                {
                    p[0] = (pixel >> 16) & 0xff;
                    p[1] = (pixel >> 8) & 0xff;
                    p[2] = pixel & 0xff;
                    p += mTarget->pitch;
                }
#else
                for (; y1 <= y2; ++y1)
                {
                    p[0] = pixel & 0xff;
                    p[1] = (pixel >> 8) & 0xff;
                    p[2] = (pixel >> 16) & 0xff;
                    p += mTarget->pitch;
                }
#endif
            }
            break;

            case 4:
            {
                for (; y1 <= y2; ++y1)
                {
                    if (mAlpha)
                    {
                        *reinterpret_cast<Uint32*>(p) =
                            SDLAlpha32(pixel, *reinterpret_cast<Uint32*>(p), mColor.a);
                    }
                    else
                    {
                        *reinterpret_cast<Uint32*>(p) = pixel;
                    }
                    p += mTarget->pitch;
                }
            }
            break;
        } // end switch

        SDL_UnlockSurface(mTarget);
    }

    void SDLGraphics::drawRectangle(const Rectangle& rectangle)
    {
        const int x1 = rectangle.x;
        const int x2 = rectangle.x + rectangle.width - 1;
        const int y1 = rectangle.y;
        const int y2 = rectangle.y + rectangle.height - 1;

        drawHLine(x1, y1, x2);
        drawHLine(x1, y2, x2);

        drawVLine(x1, y1, y2);
        drawVLine(x2, y1, y2);
    }

    void SDLGraphics::drawLine(int x1, int y1, int x2, int y2)
    {
        if (x1 == x2)
        {
            drawVLine(x1, y1, y2);
            return;
        }
        if (y1 == y2)
        {
            drawHLine(x1, y1, x2);
            return;
        }

        if (mClipStack.empty())
        {
            throw GCN_EXCEPTION("Clip stack is empty, perhaps you called a draw function outside "
                                "of _beginDraw() and _endDraw()?");
        }
        const ClipRectangle& top = mClipStack.top();

        x1 += top.xOffset;
        y1 += top.yOffset;
        x2 += top.xOffset;
        y2 += top.yOffset;

        // Draw a line with Bresenham

        const int dx = ABS(x2 - x1);
        const int dy = ABS(y2 - y1);

        if (dx > dy)
        {
            if (x1 > x2)
            {
                // swap x1, x2
                x1 ^= x2;
                x2 ^= x1;
                x1 ^= x2;

                // swap y1, y2
                y1 ^= y2;
                y2 ^= y1;
                y1 ^= y2;
            }

            if (y1 < y2)
            {
                int y = y1;
                int p = 0;

                for (int x = x1; x <= x2; x++)
                {
                    if (top.isContaining(x, y))
                    {
                        if (mAlpha)
                        {
                            SDLputPixelAlpha(mTarget, x, y, mColor);
                        }
                        else
                        {
                            SDLputPixel(mTarget, x, y, mColor);
                        }
                    }

                    p += dy;

                    if (p * 2 >= dx)
                    {
                        y++;
                        p -= dx;
                    }
                }
            }
            else
            {
                int y = y1;
                int p = 0;

                for (int x = x1; x <= x2; x++)
                {
                    if (top.isContaining(x, y))
                    {
                        if (mAlpha)
                        {
                            SDLputPixelAlpha(mTarget, x, y, mColor);
                        }
                        else
                        {
                            SDLputPixel(mTarget, x, y, mColor);
                        }
                    }

                    p += dy;

                    if (p * 2 >= dx)
                    {
                        y--;
                        p -= dx;
                    }
                }
            }
        }
        else
        {
            if (y1 > y2)
            {
                // swap y1, y2
                y1 ^= y2;
                y2 ^= y1;
                y1 ^= y2;

                // swap x1, x2
                x1 ^= x2;
                x2 ^= x1;
                x1 ^= x2;
            }

            if (x1 < x2)
            {
                int x = x1;
                int p = 0;

                for (int y = y1; y <= y2; y++)
                {
                    if (top.isContaining(x, y))
                    {
                        if (mAlpha)
                        {
                            SDLputPixelAlpha(mTarget, x, y, mColor);
                        }
                        else
                        {
                            SDLputPixel(mTarget, x, y, mColor);
                        }
                    }

                    p += dx;

                    if (p * 2 >= dy)
                    {
                        x++;
                        p -= dy;
                    }
                }
            }
            else
            {
                int x = x1;
                int p = 0;

                for (int y = y1; y <= y2; y++)
                {
                    if (top.isContaining(x, y))
                    {
                        if (mAlpha)
                        {
                            SDLputPixelAlpha(mTarget, x, y, mColor);
                        }
                        else
                        {
                            SDLputPixel(mTarget, x, y, mColor);
                        }
                    }

                    p += dx;

                    if (p * 2 >= dy)
                    {
                        x--;
                        p -= dy;
                    }
                }
            }
        }
    }

    void SDLGraphics::setColor(const Color& color)
    {
        mColor = color;

        mAlpha = color.a != 255;
    }

    const Color& SDLGraphics::getColor()
    {
        return mColor;
    }

    void SDLGraphics::drawSDLSurface(SDL_Surface* surface, SDL_Rect source, SDL_Rect destination)
    {
        if (mClipStack.empty())
        {
            throw GCN_EXCEPTION("Clip stack is empty, perhaps you called a draw function outside "
                                "of _beginDraw() and _endDraw()?");
        }
        const ClipRectangle& top = mClipStack.top();

        destination.x += top.xOffset;
        destination.y += top.yOffset;

        SDL_BlitSurface(surface, &source, mTarget, &destination);
    }
} // namespace gcn
