/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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 for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#include "SDL_draw.h"


int
SDL_DrawLine(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color)
{
    if (!dst) {
        SDL_SetError("Passed NULL destination surface");
        return -1;
    }

    /* This function doesn't work on surfaces < 8 bpp */
    if (dst->format->BitsPerPixel < 8) {
        SDL_SetError("SDL_DrawLine(): Unsupported surface format");
        return -1;
    }

    /* Perform clipping */
    /* FIXME: We don't actually want to clip, as it may change line slope */
    if (!SDL_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) {
        return (0);
    }

    switch (dst->format->BytesPerPixel) {
    case 1:
        DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL1);
        break;
    case 2:
        DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL2);
        break;
    case 3:
        SDL_Unsupported();
        return -1;
    case 4:
        DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL4);
        break;
    }
    return 0;
}

int
SDL_DrawLines(SDL_Surface * dst, const SDL_Point * points, int count,
              Uint32 color)
{
    int i;

    if (!dst) {
        SDL_SetError("Passed NULL destination surface");
        return -1;
    }

    /* This function doesn't work on surfaces < 8 bpp */
    if (dst->format->BitsPerPixel < 8) {
        SDL_SetError("SDL_DrawLine(): Unsupported surface format");
        return -1;
    }

    if (count < 2) {
        return 0;
    }

    for (i = 1; i < count; ++i) {
        int x1 = points[i-1].x;
        int y1 = points[i-1].y;
        int x2 = points[i].x;
        int y2 = points[i].y;

        /* Perform clipping */
        /* FIXME: We don't actually want to clip, as it may change line slope */
        if (!SDL_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) {
            continue;
        }

        switch (dst->format->BytesPerPixel) {
        case 1:
            DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL1);
            break;
        case 2:
            DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL2);
            break;
        case 3:
            SDL_Unsupported();
            return -1;
        case 4:
            DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL4);
            break;
        }
    }
    return 0;
}

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