/**

 * test/demos/pmc/surface.cc

 * Copyright (C) 2008 Markus Broeker

 */

#include <surface.h>

#define max(a,b) (((a) > (b)) ? (a) : (b))

#define min(a,b) (((a) < (b)) ? (a) : (b))

#define abs(a) (((a)<0) ? -(a) : (a))

#define sign(a) (((a)<0) ? -1 : (a)>0 ? 1 : 0)

Surface::Surface (int w, int h, int d)

{

    width = w;

    height = h;

    depth = d;

    SDL_Init (SDL_INIT_VIDEO);

    screen = SDL_SetVideoMode (width, height, depth, SDL_HWSURFACE);

    red = SDL_MapRGB (screen->format, 0xff, 0x00, 0x00);

    black = SDL_MapRGB (screen->format, 0x00, 0x00, 0x00);

    color = red;

}

Surface::~Surface ()

{

    SDL_Quit ();

}

void Surface::drawPixel (int x, int y)

{

    if (SDL_MUSTLOCK (screen)) {

        if (SDL_LockSurface (screen) < 0) {

            return;

        }

    }

    switch (screen->format->BytesPerPixel) {

    case 1:{                   /* vermutlich 8 Bit */

            Uint8 *bufp;

            bufp = (Uint8 *) screen->pixels + y * screen->pitch + x;

            *bufp = color;

        }

        break;

    case 2:{                   /* vermutlich 15 Bit oder 16 Bit */

            Uint16 *bufp;

            bufp = (Uint16 *) screen->pixels + y * screen->pitch / 2 + x;

            *bufp = color;

        }

        break;

    case 3:{                   /* langsamer 24-Bit-Modus, selten verwendet */

            Uint8 *bufp;

            bufp = (Uint8 *) screen->pixels + y * screen->pitch + x * 3;

            if (SDL_BYTEORDER == SDL_LIL_ENDIAN) {

                bufp[0] = color;

                bufp[1] = color >> 8;

                bufp[2] = color >> 16;

            } else {

                bufp[2] = color;

                bufp[1] = color >> 8;

                bufp[0] = color >> 16;

            }

        }

        break;

    case 4:{                   /* vermutlich 32 Bit */

            Uint32 *bufp;

            bufp = (Uint32 *) screen->pixels + y * screen->pitch / 4 + x;

            *bufp = color;

        }

        break;

    }

    if (SDL_MUSTLOCK (screen)) {

        SDL_UnlockSurface (screen);

    }

}

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

{

    int d;

    int x;

    int y;

    int ax;

    int ay;

    int sx;

    int sy;

    int dx;

    int dy;

    Uint8 *lineAddr;

    Sint32 yOffset;

    /*

     * SANITY CHECK: fix segfault in *((Uint16 *) (lineAddr + (x << 1))) = (Uint16) color;

     */

    if (y1 < 0 || y2 < 0)

        return;

    if (x1 < 0 || x2 < 0)

        return;

    dx = x2 - x1;

    ax = abs (dx) << 1;

    sx = sign (dx);

    dy = y2 - y1;

    ay = abs (dy) << 1;

    sy = sign (dy);

    yOffset = sy * screen->pitch;

    x = x1;

    y = y1;

    lineAddr = ((Uint8 *) screen->pixels) + (y * screen->pitch);

    if (ax > ay) {              /* x dominant */

        d = ay - (ax >> 1);

        for (;;) {

            *((Uint16 *) (lineAddr + (x << 1))) = (Uint16) color;

            if (x == x2) {

                return;

            }

            if (d >= 0) {

                y += sy;

                lineAddr += yOffset;

                d -= ax;

            }

            x += sx;

            d += ay;

        }

    } else {                    /* y dominant */

        d = ax - (ay >> 1);

        for (;;) {

            *((Uint16 *) (lineAddr + (x << 1))) = (Uint16) color;

            if (y == y2) {

                return;

            }

            if (d >= 0) {

                x += sx;

                d -= ay;

            }

            y += sy;

            lineAddr += yOffset;

            d += ax;

        }

    }

}

void Surface::flip ()

{

    SDL_Flip (screen);

}

void Surface::setColor (foregroundColor c)

{

    switch (c) {

    case BLACK:

        color = black;

        break;

    case RED:

        color = red;

        break;

    };

}