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SDL_drawline.c
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/*
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"
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#include "SDL_draw.h"
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SDL_DrawLine(SDL_Surface * dst, int x1, int y1, int x2, int y2, Uint32 color)
{
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if (!dst) {
SDL_SetError("Passed NULL destination surface");
return -1;
}
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/* This function doesn't work on surfaces < 8 bpp */
if (dst->format->BitsPerPixel < 8) {
SDL_SetError("SDL_DrawLine(): Unsupported surface format");
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}
/* Perform clipping */
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/* FIXME: We don't actually want to clip, as it may change line slope */
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if (!SDL_IntersectRectAndLine(&dst->clip_rect, &x1, &y1, &x2, &y2)) {
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return (0);
}
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switch (dst->format->BytesPerPixel) {
case 1:
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DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL1);
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break;
case 2:
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DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL2);
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break;
case 3:
SDL_Unsupported();
return -1;
case 4:
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DRAWLINE(x1, y1, x2, y2, DRAW_FASTSETPIXEL4);
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break;
}
return 0;
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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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/* vi: set ts=4 sw=4 expandtab: */