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Share code between fill and line drawing 

Added general RGB surface format fallbacks to drawing code
Fixed issues with destination surface alpha channel
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@slouken
slouken committed Dec 21, 2008
1 parent ab0e777 commit 2d2977caa53fad09e4cd8f90a90e8fca74f8cba7
Unified Split
Showing with 677 additions and 336 deletions.
  1. +171 −157 src/video/SDL_blendline.c
  2. +172 −122 src/video/SDL_blendrect.c
  3. +2 −0 src/video/SDL_blit.h
  4. +325 −0 src/video/SDL_draw.h
  5. +7 −57 src/video/SDL_drawline.c
328 src/video/SDL_blendline.c
View file
@@ -21,198 +21,212 @@
*/
#include "SDL_config.h"

#include "SDL_video.h"
#include "SDL_blit.h"

#define ABS(_x) ((_x) < 0 ? -(_x) : (_x))

#define SWAP(_x, _y) do { int tmp; tmp = _x; _x = _y; _y = tmp; } while (0)

#define BRESENHAM(x0, y0, x1, y1, op) \
{ \
int deltax, deltay, steep, error, xstep, ystep, x, y; \
\
deltax = ABS(x1 - x0); \
deltay = ABS(y1 - y0); \
steep = (deltay > deltax); \
if (steep) { \
SWAP(x0, y0); \
SWAP(x1, y1); \
SWAP(deltax, deltay); \
} \
error = (x1 - x0) / 2; \
y = y0; \
if (x0 > x1) { \
xstep = -1; \
} else { \
xstep = 1; \
} \
if (y0 < y1) { \
ystep = 1; \
} else { \
ystep = -1; \
} \
if (!steep) { \
for (x = x0; x != x1; x += xstep) { \
op(x, y); \
error -= deltay; \
if (error < 0) { \
y += ystep; \
error += deltax; \
} \
} \
} else { \
for (x = x0; x != x1; x += xstep) { \
op(y, x); \
error -= deltay; \
if (error < 0) { \
y += ystep; \
error += deltax; \
} \
} \
} \
}
#include "SDL_draw.h"

#define MUL(_a, _b) (((Uint16)(_a)*(Uint16)(_b))/255)
#define SHIFTAND(_v, _s, _a) (((_v)>>(_s)) & _a)

#define SETPIXEL_MASK(x, y, type, bpp, rshift, gshift, bshift, rmask, gmask, bmask) \
do { \
type *pixel = (type *)(dst->pixels + y * dst->pitch + x * bpp); \
if (a) { \
*pixel = (r<<rshift) | (g<<gshift) | (b<<bshift); \
} \
} while (0)

#define SETPIXEL_BLEND(x, y, type, bpp, rshift, gshift, bshift, rmask, gmask, bmask) \
do { \
type *pixel = (type *)(dst->pixels + y * dst->pitch + x * bpp); \
Uint8 sr = MUL(inva, SHIFTAND(*pixel, rshift, rmask)) + (Uint16) r; \
Uint8 sg = MUL(inva, SHIFTAND(*pixel, gshift, gmask)) + (Uint16) g; \
Uint8 sb = MUL(inva, SHIFTAND(*pixel, bshift, bmask)) + (Uint16) b; \
*pixel = (sr<<rshift) | (sg<<gshift) | (sb<<bshift); \
} while (0)

#define SETPIXEL_ADD(x, y, type, bpp, rshift, gshift, bshift, rmask, gmask, bmask) \
do { \
type *pixel = (type *)(dst->pixels + y * dst->pitch + x * bpp); \
Uint16 sr = SHIFTAND(*pixel, rshift, rmask) + (Uint16) r; \
Uint16 sg = SHIFTAND(*pixel, gshift, gmask) + (Uint16) g; \
Uint16 sb = SHIFTAND(*pixel, bshift, bmask) + (Uint16) b; \
if (sr>rmask) sr = rmask; \
if (sg>gmask) sg = gmask; \
if (sb>bmask) sb = bmask; \
*pixel = (sr<<rshift) | (sg<<gshift) | (sb<<bshift); \
} while (0)

#define SETPIXEL_MOD(x, y, type, bpp, rshift, gshift, bshift, rmask, gmask, bmask) \
do { \
type *pixel = (type *)(dst->pixels + y * dst->pitch + x * bpp); \
Uint8 sr = MUL(SHIFTAND(*pixel, rshift, rmask), r); \
Uint8 sg = MUL(SHIFTAND(*pixel, gshift, gmask), g); \
Uint8 sb = MUL(SHIFTAND(*pixel, bshift, bmask), b); \
*pixel = (sr<<rshift) | (sg<<gshift) | (sb<<bshift); \
} while (0)


#define SETPIXEL15_MASK(x, y) SETPIXEL_MASK(x, y, Uint16, 2, 10, 5, 0, 0x1f, 0x1f, 0x1f);
#define SETPIXEL15_BLEND(x, y) SETPIXEL_BLEND(x, y, Uint16, 2, 10, 5, 0, 0x1f, 0x1f, 0x1f);
#define SETPIXEL15_ADD(x, y) SETPIXEL_ADD(x, y, Uint16, 2, 10, 5, 0, 0x1f, 0x1f, 0x1f);
#define SETPIXEL15_MOD(x, y) SETPIXEL_MOD(x, y, Uint16, 2, 10, 5, 0, 0x1f, 0x1f, 0x1f);

#define SETPIXEL16_MASK(x, y) SETPIXEL_MASK(x, y, Uint16, 2, 11, 5, 0, 0x1f, 0x3f, 0x1f);
#define SETPIXEL16_BLEND(x, y) SETPIXEL_BLEND(x, y, Uint16, 2, 11, 5, 0, 0x1f, 0x3f, 0x1f);
#define SETPIXEL16_ADD(x, y) SETPIXEL_ADD(x, y, Uint16, 2, 11, 5, 0, 0x1f, 0x3f, 0x1f);
#define SETPIXEL16_MOD(x, y) SETPIXEL_MOD(x, y, Uint16, 2, 11, 5, 0, 0x1f, 0x3f, 0x1f);

#define SETPIXEL32_MASK(x, y) SETPIXEL_MASK(x, y, Uint32, 4, 16, 8, 0, 0xff, 0xff, 0xff);
#define SETPIXEL32_BLEND(x, y) SETPIXEL_BLEND(x, y, Uint32, 4, 16, 8, 0, 0xff, 0xff, 0xff);
#define SETPIXEL32_ADD(x, y) SETPIXEL_ADD(x, y, Uint32, 4, 16, 8, 0, 0xff, 0xff, 0xff);
#define SETPIXEL32_MOD(x, y) SETPIXEL_MOD(x, y, Uint32, 4, 16, 8, 0, 0xff, 0xff, 0xff);
static int
SDL_BlendLine_RGB555(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
unsigned inva = 0xff - a;

int
SDL_BlendLine(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_BLEND_RGB555);
break;
case SDL_BLENDMODE_ADD:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_ADD_RGB555);
break;
case SDL_BLENDMODE_MOD:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_MOD_RGB555);
break;
default:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_RGB555);
break;
}
return 0;
}

static int
SDL_BlendLine_RGB565(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
Uint8 inva = 0xff - a;
/* This function doesn't work on surfaces < 8 bpp */
if (dst->format->BitsPerPixel < 8) {
SDL_SetError("SDL_BlendLine(): Unsupported surface format");
return (-1);
unsigned inva = 0xff - a;

switch (blendMode) {
case SDL_BLENDMODE_BLEND:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_BLEND_RGB565);
break;
case SDL_BLENDMODE_ADD:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_ADD_RGB565);
break;
case SDL_BLENDMODE_MOD:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_MOD_RGB565);
break;
default:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_RGB565);
break;
}
return 0;
}

/* Perform clipping */
/* FIXME
if (!SDL_IntersectRect(dstrect, &dst->clip_rect, dstrect)) {
return (0);
}
*/
static int
SDL_BlendLine_RGB888(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
unsigned inva = 0xff - a;

if ((blendMode == SDL_BLENDMODE_BLEND)
|| (blendMode == SDL_BLENDMODE_ADD)) {
r = MUL(r, a);
g = MUL(g, a);
b = MUL(b, a);
switch (blendMode) {
case SDL_BLENDMODE_BLEND:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_BLEND_RGB888);
break;
case SDL_BLENDMODE_ADD:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_ADD_RGB888);
break;
case SDL_BLENDMODE_MOD:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_MOD_RGB888);
break;
default:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY_RGB888);
break;
}
switch (dst->format->BitsPerPixel) {
case 15:
return 0;
}

static int
SDL_BlendLine_RGB(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
SDL_PixelFormat *fmt = dst->format;
unsigned inva = 0xff - a;

switch (fmt->BytesPerPixel) {
case 2:
switch (blendMode) {
case SDL_BLENDMODE_MASK:
BRESENHAM(x1, y1, x2, y2, SETPIXEL15_MASK);
break;
case SDL_BLENDMODE_BLEND:
BRESENHAM(x1, y1, x2, y2, SETPIXEL15_BLEND);
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY2_BLEND_RGB);
break;
case SDL_BLENDMODE_ADD:
BRESENHAM(x1, y1, x2, y2, SETPIXEL15_ADD);
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY2_ADD_RGB);
break;
case SDL_BLENDMODE_MOD:
BRESENHAM(x1, y1, x2, y2, SETPIXEL15_MOD);
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY2_MOD_RGB);
break;
default:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY2_RGB);
break;
}
break;
case 16:
return 0;
case 4:
switch (blendMode) {
case SDL_BLENDMODE_MASK:
BRESENHAM(x1, y1, x2, y2, SETPIXEL16_MASK);
break;
case SDL_BLENDMODE_BLEND:
BRESENHAM(x1, y1, x2, y2, SETPIXEL16_BLEND);
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY4_BLEND_RGB);
break;
case SDL_BLENDMODE_ADD:
BRESENHAM(x1, y1, x2, y2, SETPIXEL16_ADD);
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY4_ADD_RGB);
break;
case SDL_BLENDMODE_MOD:
BRESENHAM(x1, y1, x2, y2, SETPIXEL16_MOD);
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY4_MOD_RGB);
break;
default:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY4_RGB);
break;
}
break;
case 24:
case 32:
if (dst->format->BytesPerPixel != 4) {
SDL_Unsupported();
return -1;
}
return 0;
default:
SDL_Unsupported();
return -1;
}
}

static int
SDL_BlendLine_RGBA(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
SDL_PixelFormat *fmt = dst->format;
unsigned inva = 0xff - a;

switch (fmt->BytesPerPixel) {
case 4:
switch (blendMode) {
case SDL_BLENDMODE_MASK:
BRESENHAM(x1, y1, x2, y2, SETPIXEL32_MASK);
break;
case SDL_BLENDMODE_BLEND:
BRESENHAM(x1, y1, x2, y2, SETPIXEL32_BLEND);
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY4_BLEND_RGBA);
break;
case SDL_BLENDMODE_ADD:
BRESENHAM(x1, y1, x2, y2, SETPIXEL32_ADD);
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY4_ADD_RGBA);
break;
case SDL_BLENDMODE_MOD:
BRESENHAM(x1, y1, x2, y2, SETPIXEL32_MOD);
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY4_MOD_RGBA);
break;
default:
BRESENHAM(x1, y1, x2, y2, DRAW_SETPIXELXY4_RGBA);
break;
}
break;
return 0;
default:
SDL_Unsupported();
return -1;
}
return 0;
}

int
SDL_BlendLine(SDL_Surface * dst, int x1, int y1, int x2, int y2,
int blendMode, Uint8 r, Uint8 g, Uint8 b, Uint8 a)
{
SDL_PixelFormat *fmt = dst->format;

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

/* Perform clipping */
/* FIXME
if (!SDL_IntersectRect(dstrect, &dst->clip_rect, dstrect)) {
return (0);
}
*/

if ((blendMode == SDL_BLENDMODE_BLEND)
|| (blendMode == SDL_BLENDMODE_ADD)) {
r = DRAW_MUL(r, a);
g = DRAW_MUL(g, a);
b = DRAW_MUL(b, a);
}

switch (fmt->BitsPerPixel) {
case 15:
switch (fmt->Rmask) {
case 0x7C00:
return SDL_BlendLine_RGB555(dst, x1, y1, x2, y2, blendMode, r, g,
b, a);
}
break;
case 16:
switch (fmt->Rmask) {
case 0xF800:
return SDL_BlendLine_RGB565(dst, x1, y1, x2, y2, blendMode, r, g,
b, a);
}
break;
case 32:
switch (fmt->Rmask) {
case 0x00FF0000:
if (!fmt->Amask) {
return SDL_BlendLine_RGB888(dst, x1, y1, x2, y2, blendMode, r,
g, b, a);
}
break;
}
default:
break;
}

if (!fmt->Amask) {
return SDL_BlendLine_RGB(dst, x1, y1, x2, y2, blendMode, r, g, b, a);
} else {
return SDL_BlendLine_RGBA(dst, x1, y1, x2, y2, blendMode, r, g, b, a);
}
}

/* vi: set ts=4 sw=4 expandtab: */

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