SDL_drawline.h File Reference

#include "../../SDL_internal.h"

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Functions
int	SDL_DrawLine (SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color)
int	SDL_DrawLines (SDL_Surface *dst, const SDL_Point *points, int count, Uint32 color)

Function Documentation

int SDL_DrawLine	(	SDL_Surface *	dst,
		int	x1,
		int	y1,
		int	x2,
		int	y2,
		Uint32	color
	)

Definition at line 142 of file SDL_drawline.c.

References SDL_Surface::clip_rect, SDL_Surface::format, SDL_CalculateDrawLineFunc(), SDL_IntersectRectAndLine, SDL_SetError, and SDL_TRUE.

{
    DrawLineFunc func;

    if (!dst) {
        return SDL_SetError("SDL_DrawLine(): Passed NULL destination surface");
    }

    func = SDL_CalculateDrawLineFunc(dst->format);
    if (!func) {
        return SDL_SetError("SDL_DrawLine(): Unsupported surface format");
    }

    /* 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;
    }

    func(dst, x1, y1, x2, y2, color, SDL_TRUE);
    return 0;
}

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

Definition at line 166 of file SDL_drawline.c.

References SDL_Surface::clip_rect, SDL_Surface::format, i, SDL_CalculateDrawLineFunc(), SDL_DrawPoint(), SDL_IntersectRectAndLine, SDL_SetError, SDL_Point::x, and SDL_Point::y.

Referenced by SW_RenderDrawLines().

{
    int i;
    int x1, y1;
    int x2, y2;
    SDL_bool draw_end;
    DrawLineFunc func;

    if (!dst) {
        return SDL_SetError("SDL_DrawLines(): Passed NULL destination surface");
    }

    func = SDL_CalculateDrawLineFunc(dst->format);
    if (!func) {
        return SDL_SetError("SDL_DrawLines(): Unsupported surface format");
    }

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

        /* Draw the end if it was clipped */
        draw_end = (x2 != points[i].x || y2 != points[i].y);

        func(dst, x1, y1, x2, y2, color, draw_end);
    }
    if (points[0].x != points[count-1].x || points[0].y != points[count-1].y) {
        SDL_DrawPoint(dst, points[count-1].x, points[count-1].y, color);
    }
    return 0;
}