SDL_drawline.c File Reference

#include "../../SDL_internal.h"
#include "SDL_draw.h"
#include "SDL_drawline.h"
#include "SDL_drawpoint.h"

Include dependency graph for SDL_drawline.c:

Go to the source code of this file.

Typedefs
typedef void(*	DrawLineFunc )(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, SDL_bool draw_end)

Functions
static void	SDL_DrawLine1 (SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, SDL_bool draw_end)
static void	SDL_DrawLine2 (SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, SDL_bool draw_end)
static void	SDL_DrawLine4 (SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, SDL_bool draw_end)
static DrawLineFunc	SDL_CalculateDrawLineFunc (const SDL_PixelFormat *fmt)
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)

Typedef Documentation

typedef void(* DrawLineFunc)(SDL_Surface *dst, int x1, int y1, int x2, int y2, Uint32 color, SDL_bool draw_end)

Definition at line 120 of file SDL_drawline.c.

Function Documentation

static DrawLineFunc SDL_CalculateDrawLineFunc ( const SDL_PixelFormat *  fmt )

static

Definition at line 125 of file SDL_drawline.c.

References SDL_PixelFormat::BitsPerPixel, SDL_PixelFormat::BytesPerPixel, NULL, SDL_DrawLine1(), SDL_DrawLine2(), and SDL_DrawLine4().

Referenced by SDL_DrawLine(), and SDL_DrawLines().

{
    switch (fmt->BytesPerPixel) {
    case 1:
        if (fmt->BitsPerPixel < 8) {
            break;
        }
        return SDL_DrawLine1;
    case 2:
        return SDL_DrawLine2;
    case 4:
        return SDL_DrawLine4;
    }
    return NULL;
}

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;
}

static void SDL_DrawLine1 ( SDL_Surface *  dst, int  x1, int  y1, int  x2, int  y2, Uint32  color, SDL_bool  draw_end  )

static

Definition at line 31 of file SDL_drawline.c.

References ABS, BLINE, SDL_PixelFormat::BytesPerPixel, DLINE, DRAW_FASTSETPIXEL1, DRAW_FASTSETPIXELXY1, SDL_Surface::format, SDL_Surface::pitch, SDL_Surface::pixels, SDL_memset, and VLINE.

Referenced by SDL_CalculateDrawLineFunc().

{
    if (y1 == y2) {
        int length;
        int pitch = (dst->pitch / dst->format->BytesPerPixel);
        Uint8 *pixel;
        if (x1 <= x2) {
            pixel = (Uint8 *)dst->pixels + y1 * pitch + x1;
            length = draw_end ? (x2-x1+1) : (x2-x1);
        } else {
            pixel = (Uint8 *)dst->pixels + y1 * pitch + x2;
            if (!draw_end) {
                ++pixel;
            }
            length = draw_end ? (x1-x2+1) : (x1-x2);
        }
        SDL_memset(pixel, color, length);
    } else if (x1 == x2) {
        VLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end);
    } else if (ABS(x1 - x2) == ABS(y1 - y2)) {
        DLINE(Uint8, DRAW_FASTSETPIXEL1, draw_end);
    } else {
        BLINE(x1, y1, x2, y2, DRAW_FASTSETPIXELXY1, draw_end);
    }
}

static void SDL_DrawLine2 ( SDL_Surface *  dst, int  x1, int  y1, int  x2, int  y2, Uint32  color, SDL_bool  draw_end  )

static

Definition at line 59 of file SDL_drawline.c.

References AALINE, ABS, DLINE, DRAW_FASTSETPIXEL2, DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY2_BLEND_RGB, DRAW_SETPIXELXY_BLEND_RGB555, DRAW_SETPIXELXY_BLEND_RGB565, SDL_Surface::format, HLINE, SDL_PixelFormat::Rmask, SDL_GetRGBA, and VLINE.

Referenced by SDL_CalculateDrawLineFunc().

{
    if (y1 == y2) {
        HLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end);
    } else if (x1 == x2) {
        VLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end);
    } else if (ABS(x1 - x2) == ABS(y1 - y2)) {
        DLINE(Uint16, DRAW_FASTSETPIXEL2, draw_end);
    } else {
        Uint8 _r, _g, _b, _a;
        const SDL_PixelFormat * fmt = dst->format;
        SDL_GetRGBA(color, fmt, &_r, &_g, &_b, &_a);
        if (fmt->Rmask == 0x7C00) {
            AALINE(x1, y1, x2, y2,
                   DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY_BLEND_RGB555,
                   draw_end);
        } else if (fmt->Rmask == 0xF800) {
            AALINE(x1, y1, x2, y2,
                   DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY_BLEND_RGB565,
                   draw_end);
        } else {
            AALINE(x1, y1, x2, y2,
                   DRAW_FASTSETPIXELXY2, DRAW_SETPIXELXY2_BLEND_RGB,
                   draw_end);
        }
    }
}

static void SDL_DrawLine4 ( SDL_Surface *  dst, int  x1, int  y1, int  x2, int  y2, Uint32  color, SDL_bool  draw_end  )

static

Definition at line 89 of file SDL_drawline.c.

References AALINE, ABS, SDL_PixelFormat::Amask, DLINE, DRAW_FASTSETPIXEL4, DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY4_BLEND_RGB, DRAW_SETPIXELXY_BLEND_ARGB8888, DRAW_SETPIXELXY_BLEND_RGB888, SDL_Surface::format, HLINE, SDL_PixelFormat::Rmask, SDL_GetRGBA, and VLINE.

Referenced by SDL_CalculateDrawLineFunc().

{
    if (y1 == y2) {
        HLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end);
    } else if (x1 == x2) {
        VLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end);
    } else if (ABS(x1 - x2) == ABS(y1 - y2)) {
        DLINE(Uint32, DRAW_FASTSETPIXEL4, draw_end);
    } else {
        Uint8 _r, _g, _b, _a;
        const SDL_PixelFormat * fmt = dst->format;
        SDL_GetRGBA(color, fmt, &_r, &_g, &_b, &_a);
        if (fmt->Rmask == 0x00FF0000) {
            if (!fmt->Amask) {
                AALINE(x1, y1, x2, y2,
                       DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY_BLEND_RGB888,
                       draw_end);
            } else {
                AALINE(x1, y1, x2, y2,
                       DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY_BLEND_ARGB8888,
                       draw_end);
            }
        } else {
            AALINE(x1, y1, x2, y2,
                   DRAW_FASTSETPIXELXY4, DRAW_SETPIXELXY4_BLEND_RGB,
                   draw_end);
        }
    }
}

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;
}