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SDL_pixels.c
833 lines (765 loc) · 21.8 KB
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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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
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Lesser General Public License for more details.
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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
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Sam Lantinga
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slouken@libsdl.org
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*/
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#include "SDL_config.h"
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/* General (mostly internal) pixel/color manipulation routines for SDL */
#include "SDL_endian.h"
#include "SDL_video.h"
#include "SDL_sysvideo.h"
#include "SDL_blit.h"
#include "SDL_pixels_c.h"
#include "SDL_RLEaccel_c.h"
/* Helper functions */
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SDL_bool
SDL_PixelFormatEnumToMasks(Uint32 format, int *bpp, Uint32 * Rmask,
Uint32 * Gmask, Uint32 * Bmask, Uint32 * Amask)
{
Uint32 masks[4];
/* Initialize the values here */
if (SDL_BITSPERPIXEL(format) == 24) {
*bpp = SDL_BYTESPERPIXEL(format) * 8;
} else {
*bpp = SDL_BITSPERPIXEL(format);
}
*Rmask = *Gmask = *Bmask = *Amask = 0;
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if (SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED8 &&
SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED16 &&
SDL_PIXELTYPE(format) != SDL_PIXELTYPE_PACKED32) {
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/* Not a format that uses masks */
return SDL_TRUE;
}
switch (SDL_PIXELLAYOUT(format)) {
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case SDL_PACKEDLAYOUT_332:
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masks[0] = 0x00000000;
masks[1] = 0x000000E0;
masks[2] = 0x0000001C;
masks[3] = 0x00000003;
break;
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case SDL_PACKEDLAYOUT_4444:
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masks[0] = 0x0000F000;
masks[1] = 0x00000F00;
masks[2] = 0x000000F0;
masks[3] = 0x0000000F;
break;
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case SDL_PACKEDLAYOUT_1555:
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masks[0] = 0x00008000;
masks[1] = 0x00007C00;
masks[2] = 0x000003E0;
masks[3] = 0x0000001F;
break;
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case SDL_PACKEDLAYOUT_565:
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masks[0] = 0x00000000;
masks[1] = 0x0000F800;
masks[2] = 0x000007E0;
masks[3] = 0x0000001F;
break;
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case SDL_PACKEDLAYOUT_8888:
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masks[0] = 0xFF000000;
masks[1] = 0x00FF0000;
masks[2] = 0x0000FF00;
masks[3] = 0x000000FF;
break;
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case SDL_PACKEDLAYOUT_2101010:
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masks[0] = 0xC0000000;
masks[1] = 0x3FF00000;
masks[2] = 0x000FFC00;
masks[3] = 0x000003FF;
break;
default:
/* Unknown layout */
return SDL_FALSE;
}
switch (SDL_PIXELORDER(format)) {
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case SDL_PACKEDORDER_XRGB:
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*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
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case SDL_PACKEDORDER_RGBX:
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*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
break;
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case SDL_PACKEDORDER_ARGB:
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*Amask = masks[0];
*Rmask = masks[1];
*Gmask = masks[2];
*Bmask = masks[3];
break;
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case SDL_PACKEDORDER_RGBA:
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*Rmask = masks[0];
*Gmask = masks[1];
*Bmask = masks[2];
*Amask = masks[3];
break;
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case SDL_PACKEDORDER_XBGR:
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*Bmask = masks[1];
*Gmask = masks[2];
*Rmask = masks[3];
break;
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case SDL_PACKEDORDER_BGRX:
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*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
break;
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case SDL_PACKEDORDER_BGRA:
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*Bmask = masks[0];
*Gmask = masks[1];
*Rmask = masks[2];
*Amask = masks[3];
break;
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case SDL_PACKEDORDER_ABGR:
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*Amask = masks[0];
*Bmask = masks[1];
*Gmask = masks[2];
*Rmask = masks[3];
break;
default:
/* Unknown order */
return SDL_FALSE;
}
return SDL_TRUE;
}
Uint32
SDL_MasksToPixelFormatEnum(int bpp, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask,
Uint32 Amask)
{
switch (bpp) {
case 8:
switch (Rmask) {
case 0:
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return SDL_PIXELFORMAT_INDEX8;
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case 0xE0:
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return SDL_PIXELFORMAT_RGB332;
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}
break;
case 12:
switch (Rmask) {
case 0x0F00:
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return SDL_PIXELFORMAT_RGB444;
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}
break;
case 15:
switch (Rmask) {
case 0x7C00:
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return SDL_PIXELFORMAT_RGB555;
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}
break;
case 16:
switch (Rmask) {
case 0x0F00:
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return SDL_PIXELFORMAT_ARGB4444;
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case 0x7C00:
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return SDL_PIXELFORMAT_ARGB1555;
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case 0xF800:
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return SDL_PIXELFORMAT_RGB565;
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}
break;
case 32:
switch (Rmask) {
case 0xFF000000:
if (Amask == 0x000000FF) {
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return SDL_PIXELFORMAT_RGBA8888;
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}
break;
case 0x00FF0000:
if (Amask == 0xFF000000) {
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return SDL_PIXELFORMAT_ARGB8888;
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} else {
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return SDL_PIXELFORMAT_RGB888;
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}
break;
case 0x0000FF00:
if (Amask == 0x000000FF) {
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return SDL_PIXELFORMAT_BGRA8888;
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}
break;
case 0x000000FF:
if (Amask == 0xFF000000) {
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return SDL_PIXELFORMAT_ABGR8888;
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} else {
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return SDL_PIXELFORMAT_BGR888;
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}
break;
case 0x3FF00000:
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return SDL_PIXELFORMAT_ARGB2101010;
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}
}
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return SDL_PIXELFORMAT_UNKNOWN;
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}
SDL_Palette *
SDL_AllocPalette(int ncolors)
{
SDL_Palette *palette;
palette = (SDL_Palette *) SDL_malloc(sizeof(*palette));
if (!palette) {
SDL_OutOfMemory();
return NULL;
}
palette->colors =
(SDL_Color *) SDL_malloc(ncolors * sizeof(*palette->colors));
if (!palette->colors) {
SDL_free(palette);
return NULL;
}
palette->ncolors = ncolors;
palette->watch = NULL;
palette->refcount = 1;
SDL_memset(palette->colors, 0xFF, ncolors * sizeof(*palette->colors));
return palette;
}
int
SDL_AddPaletteWatch(SDL_Palette * palette, SDL_PaletteChangedFunc callback,
void *userdata)
{
SDL_PaletteWatch *watch;
if (!palette) {
return -1;
}
watch = (SDL_PaletteWatch *) SDL_malloc(sizeof(*watch));
if (!watch) {
SDL_OutOfMemory();
return -1;
}
watch->callback = callback;
watch->userdata = userdata;
watch->next = palette->watch;
palette->watch = watch;
++palette->refcount;
return 0;
}
void
SDL_DelPaletteWatch(SDL_Palette * palette, SDL_PaletteChangedFunc callback,
void *userdata)
{
SDL_PaletteWatch *prev, *watch;
if (!palette) {
return;
}
for (prev = NULL, watch = palette->watch; watch;
prev = watch, watch = watch->next) {
if (watch->callback == callback && watch->userdata == userdata) {
if (prev) {
prev->next = watch->next;
} else {
palette->watch = watch->next;
}
SDL_free(watch);
SDL_FreePalette(palette);
return;
}
}
}
int
SDL_SetPaletteColors(SDL_Palette * palette, const SDL_Color * colors,
int firstcolor, int ncolors)
{
SDL_PaletteWatch *watch;
int status = 0;
/* Verify the parameters */
if (!palette) {
return -1;
}
if (ncolors > (palette->ncolors - firstcolor)) {
ncolors = (palette->ncolors - firstcolor);
status = -1;
}
if (colors != (palette->colors + firstcolor)) {
SDL_memcpy(palette->colors + firstcolor, colors,
ncolors * sizeof(*colors));
}
for (watch = palette->watch; watch; watch = watch->next) {
if (watch->callback(watch->userdata, palette) < 0) {
status = -1;
}
}
return status;
}
void
SDL_FreePalette(SDL_Palette * palette)
{
if (!palette) {
return;
}
if (--palette->refcount > 0) {
return;
}
if (palette->colors) {
SDL_free(palette->colors);
}
SDL_free(palette);
}
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/*
* Allocate a pixel format structure and fill it according to the given info.
*/
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SDL_PixelFormat *
SDL_AllocFormat(int bpp,
Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
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{
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SDL_PixelFormat *format;
Uint32 mask;
/* Allocate an empty pixel format structure */
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format = SDL_calloc(1, sizeof(*format));
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if (format == NULL) {
SDL_OutOfMemory();
return (NULL);
}
format->alpha = SDL_ALPHA_OPAQUE;
/* Set up the format */
format->BitsPerPixel = bpp;
format->BytesPerPixel = (bpp + 7) / 8;
if (Rmask || Bmask || Gmask) { /* Packed pixels with custom mask */
format->Rshift = 0;
format->Rloss = 8;
if (Rmask) {
for (mask = Rmask; !(mask & 0x01); mask >>= 1)
++format->Rshift;
for (; (mask & 0x01); mask >>= 1)
--format->Rloss;
}
format->Gshift = 0;
format->Gloss = 8;
if (Gmask) {
for (mask = Gmask; !(mask & 0x01); mask >>= 1)
++format->Gshift;
for (; (mask & 0x01); mask >>= 1)
--format->Gloss;
}
format->Bshift = 0;
format->Bloss = 8;
if (Bmask) {
for (mask = Bmask; !(mask & 0x01); mask >>= 1)
++format->Bshift;
for (; (mask & 0x01); mask >>= 1)
--format->Bloss;
}
format->Ashift = 0;
format->Aloss = 8;
if (Amask) {
for (mask = Amask; !(mask & 0x01); mask >>= 1)
++format->Ashift;
for (; (mask & 0x01); mask >>= 1)
--format->Aloss;
}
format->Rmask = Rmask;
format->Gmask = Gmask;
format->Bmask = Bmask;
format->Amask = Amask;
} else if (bpp > 8) { /* Packed pixels with standard mask */
/* R-G-B */
if (bpp > 24)
bpp = 24;
format->Rloss = 8 - (bpp / 3);
format->Gloss = 8 - (bpp / 3) - (bpp % 3);
format->Bloss = 8 - (bpp / 3);
format->Rshift = ((bpp / 3) + (bpp % 3)) + (bpp / 3);
format->Gshift = (bpp / 3);
format->Bshift = 0;
format->Rmask = ((0xFF >> format->Rloss) << format->Rshift);
format->Gmask = ((0xFF >> format->Gloss) << format->Gshift);
format->Bmask = ((0xFF >> format->Bloss) << format->Bshift);
} else {
/* Palettized formats have no mask info */
format->Rloss = 8;
format->Gloss = 8;
format->Bloss = 8;
format->Aloss = 8;
format->Rshift = 0;
format->Gshift = 0;
format->Bshift = 0;
format->Ashift = 0;
format->Rmask = 0;
format->Gmask = 0;
format->Bmask = 0;
format->Amask = 0;
}
format->palette = NULL;
return (format);
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}
/*
* Change any previous mappings from/to the new surface format
*/
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void
SDL_FormatChanged(SDL_Surface * surface)
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{
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static int format_version = 0;
++format_version;
if (format_version < 0) { /* It wrapped... */
format_version = 1;
}
surface->format_version = format_version;
SDL_InvalidateMap(surface->map);
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}
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/*
* Free a previously allocated format structure
*/
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void
SDL_FreeFormat(SDL_PixelFormat * format)
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{
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if (!format) {
return;
}
SDL_free(format);
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}
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/*
* Calculate an 8-bit (3 red, 3 green, 2 blue) dithered palette of colors
*/
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void
SDL_DitherColors(SDL_Color * colors, int bpp)
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{
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int i;
if (bpp != 8)
return; /* only 8bpp supported right now */
for (i = 0; i < 256; i++) {
int r, g, b;
/* map each bit field to the full [0, 255] interval,
so 0 is mapped to (0, 0, 0) and 255 to (255, 255, 255) */
r = i & 0xe0;
r |= r >> 3 | r >> 6;
colors[i].r = r;
g = (i << 3) & 0xe0;
g |= g >> 3 | g >> 6;
colors[i].g = g;
b = i & 0x3;
b |= b << 2;
b |= b << 4;
colors[i].b = b;
colors[i].unused = SDL_ALPHA_OPAQUE;
}
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}
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/*
* Calculate the pad-aligned scanline width of a surface
*/
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int
SDL_CalculatePitch(SDL_Surface * surface)
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{
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int pitch;
/* Surface should be 4-byte aligned for speed */
pitch = surface->w * surface->format->BytesPerPixel;
switch (surface->format->BitsPerPixel) {
case 1:
pitch = (pitch + 7) / 8;
break;
case 4:
pitch = (pitch + 1) / 2;
break;
default:
break;
}
pitch = (pitch + 3) & ~3; /* 4-byte aligning */
return (pitch);
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}
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/*
* Match an RGB value to a particular palette index
*/
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Uint8
SDL_FindColor(SDL_Palette * pal, Uint8 r, Uint8 g, Uint8 b)
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{
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/* Do colorspace distance matching */
unsigned int smallest;
unsigned int distance;
int rd, gd, bd;
int i;
Uint8 pixel = 0;
smallest = ~0;
for (i = 0; i < pal->ncolors; ++i) {
rd = pal->colors[i].r - r;
gd = pal->colors[i].g - g;
bd = pal->colors[i].b - b;
distance = (rd * rd) + (gd * gd) + (bd * bd);
if (distance < smallest) {
pixel = i;
if (distance == 0) { /* Perfect match! */
break;
}
smallest = distance;
}
}
return (pixel);
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}
/* Find the opaque pixel value corresponding to an RGB triple */
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Uint32
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SDL_MapRGB(const SDL_PixelFormat * const format, const Uint8 r, const Uint8 g,
const Uint8 b)
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{
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if (format->palette == NULL) {
return (r >> format->Rloss) << format->Rshift
| (g >> format->Gloss) << format->Gshift
| (b >> format->Bloss) << format->Bshift | format->Amask;
} else {
return SDL_FindColor(format->palette, r, g, b);
}
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}
/* Find the pixel value corresponding to an RGBA quadruple */
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Uint32
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SDL_MapRGBA(const SDL_PixelFormat * const format, const Uint8 r, const Uint8 g,
const Uint8 b, const Uint8 a)
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{
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if (format->palette == NULL) {
return (r >> format->Rloss) << format->Rshift
| (g >> format->Gloss) << format->Gshift
| (b >> format->Bloss) << format->Bshift
| ((a >> format->Aloss) << format->Ashift & format->Amask);
} else {
return SDL_FindColor(format->palette, r, g, b);
}
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}
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void
SDL_GetRGBA(Uint32 pixel, SDL_PixelFormat * fmt,
Uint8 * r, Uint8 * g, Uint8 * b, Uint8 * a)
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{
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if (fmt->palette == NULL) {
/*
* This makes sure that the result is mapped to the
* interval [0..255], and the maximum value for each
* component is 255. This is important to make sure
* that white is indeed reported as (255, 255, 255),
* and that opaque alpha is 255.
* This only works for RGB bit fields at least 4 bit
* wide, which is almost always the case.
*/
unsigned v;
v = (pixel & fmt->Rmask) >> fmt->Rshift;
*r = (v << fmt->Rloss) + (v >> (8 - (fmt->Rloss << 1)));
v = (pixel & fmt->Gmask) >> fmt->Gshift;
*g = (v << fmt->Gloss) + (v >> (8 - (fmt->Gloss << 1)));
v = (pixel & fmt->Bmask) >> fmt->Bshift;
*b = (v << fmt->Bloss) + (v >> (8 - (fmt->Bloss << 1)));
if (fmt->Amask) {
v = (pixel & fmt->Amask) >> fmt->Ashift;
*a = (v << fmt->Aloss) + (v >> (8 - (fmt->Aloss << 1)));
} else {
*a = SDL_ALPHA_OPAQUE;
}
} else {
*r = fmt->palette->colors[pixel].r;
*g = fmt->palette->colors[pixel].g;
*b = fmt->palette->colors[pixel].b;
*a = SDL_ALPHA_OPAQUE;
}
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}
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void
SDL_GetRGB(Uint32 pixel, SDL_PixelFormat * fmt, Uint8 * r, Uint8 * g,
Uint8 * b)
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{
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if (fmt->palette == NULL) {
/* the note for SDL_GetRGBA above applies here too */
unsigned v;
v = (pixel & fmt->Rmask) >> fmt->Rshift;
*r = (v << fmt->Rloss) + (v >> (8 - (fmt->Rloss << 1)));
v = (pixel & fmt->Gmask) >> fmt->Gshift;
*g = (v << fmt->Gloss) + (v >> (8 - (fmt->Gloss << 1)));
v = (pixel & fmt->Bmask) >> fmt->Bshift;
*b = (v << fmt->Bloss) + (v >> (8 - (fmt->Bloss << 1)));
} else {
*r = fmt->palette->colors[pixel].r;
*g = fmt->palette->colors[pixel].g;
*b = fmt->palette->colors[pixel].b;
}
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}
/* Apply gamma to a set of colors - this is easy. :) */
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void
SDL_ApplyGamma(Uint16 * gamma, SDL_Color * colors, SDL_Color * output,
int ncolors)
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{
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int i;
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for (i = 0; i < ncolors; ++i) {
output[i].r = gamma[0 * 256 + colors[i].r] >> 8;
output[i].g = gamma[1 * 256 + colors[i].g] >> 8;
output[i].b = gamma[2 * 256 + colors[i].b] >> 8;
}
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}
/* Map from Palette to Palette */
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static Uint8 *
Map1to1(SDL_Palette * src, SDL_Palette * dst, int *identical)
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{
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Uint8 *map;
int i;
if (identical) {
if (src->ncolors <= dst->ncolors) {
/* If an identical palette, no need to map */
if (src == dst
||
(SDL_memcmp
(src->colors, dst->colors,
src->ncolors * sizeof(SDL_Color)) == 0)) {
*identical = 1;
return (NULL);
}
}
*identical = 0;
}
map = (Uint8 *) SDL_malloc(src->ncolors);
if (map == NULL) {
SDL_OutOfMemory();
return (NULL);
}
for (i = 0; i < src->ncolors; ++i) {
map[i] = SDL_FindColor(dst,
src->colors[i].r, src->colors[i].g,
src->colors[i].b);
}
return (map);
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}
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/* Map from Palette to BitField */
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static Uint8 *
Map1toN(SDL_PixelFormat * src, SDL_PixelFormat * dst)
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{
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Uint8 *map;
int i;
int bpp;
unsigned alpha;
SDL_Palette *pal = src->palette;
bpp = ((dst->BytesPerPixel == 3) ? 4 : dst->BytesPerPixel);
map = (Uint8 *) SDL_malloc(pal->ncolors * bpp);
if (map == NULL) {
SDL_OutOfMemory();
return (NULL);
}
alpha = dst->Amask ? src->alpha : 0;
/* We memory copy to the pixel map so the endianness is preserved */
for (i = 0; i < pal->ncolors; ++i) {
ASSEMBLE_RGBA(&map[i * bpp], dst->BytesPerPixel, dst,
pal->colors[i].r, pal->colors[i].g,
pal->colors[i].b, alpha);
}
return (map);
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}
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/* Map from BitField to Dithered-Palette to Palette */
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static Uint8 *
MapNto1(SDL_PixelFormat * src, SDL_PixelFormat * dst, int *identical)
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{
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/* Generate a 256 color dither palette */
SDL_Palette dithered;
SDL_Color colors[256];
SDL_Palette *pal = dst->palette;
dithered.ncolors = 256;
SDL_DitherColors(colors, 8);
dithered.colors = colors;
return (Map1to1(&dithered, pal, identical));
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}
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SDL_BlitMap *
SDL_AllocBlitMap(void)
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{
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SDL_BlitMap *map;
/* Allocate the empty map */
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map = (SDL_BlitMap *) SDL_calloc(1, sizeof(*map));
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if (map == NULL) {
SDL_OutOfMemory();
return (NULL);
}
/* Allocate the software blit data */
map->sw_data =
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(struct private_swaccel *) SDL_calloc(1, sizeof(*map->sw_data));
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if (map->sw_data == NULL) {
SDL_FreeBlitMap(map);
SDL_OutOfMemory();
return (NULL);
}
/* It's ready to go */
return (map);
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}
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void
SDL_InvalidateMap(SDL_BlitMap * map)
739
{
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if (!map) {
return;
}
map->dst = NULL;
map->format_version = (unsigned int) -1;
if (map->table) {
SDL_free(map->table);
map->table = NULL;
}
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}
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int
SDL_MapSurface(SDL_Surface * src, SDL_Surface * dst)
752
{
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SDL_PixelFormat *srcfmt;
SDL_PixelFormat *dstfmt;
SDL_BlitMap *map;
/* Clear out any previous mapping */
map = src->map;
if ((src->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
SDL_UnRLESurface(src, 1);
}
SDL_InvalidateMap(map);
/* Figure out what kind of mapping we're doing */
map->identity = 0;
srcfmt = src->format;
dstfmt = dst->format;
switch (srcfmt->BytesPerPixel) {
case 1:
switch (dstfmt->BytesPerPixel) {
case 1:
/* Palette --> Palette */
map->table =
Map1to1(srcfmt->palette, dstfmt->palette, &map->identity);
if (!map->identity) {
if (map->table == NULL) {
return (-1);
}
}
if (srcfmt->BitsPerPixel != dstfmt->BitsPerPixel)
map->identity = 0;
break;
default:
/* Palette --> BitField */
map->table = Map1toN(srcfmt, dstfmt);
if (map->table == NULL) {
return (-1);
}
break;
}
break;
default:
switch (dstfmt->BytesPerPixel) {
case 1:
/* BitField --> Palette */
map->table = MapNto1(srcfmt, dstfmt, &map->identity);
if (!map->identity) {
if (map->table == NULL) {
return (-1);
}
}
map->identity = 0; /* Don't optimize to copy */
break;
default:
/* BitField --> BitField */
if (FORMAT_EQUAL(srcfmt, dstfmt))
map->identity = 1;
break;
}
break;
}
map->dst = dst;
map->format_version = dst->format_version;
/* Choose your blitters wisely */
return (SDL_CalculateBlit(src));
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}
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822
void
SDL_FreeBlitMap(SDL_BlitMap * map)
823
{
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if (map) {
SDL_InvalidateMap(map);
if (map->sw_data != NULL) {
SDL_free(map->sw_data);
}
SDL_free(map);
}
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}
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/* vi: set ts=4 sw=4 expandtab: */