/*

Simple DirectMedia Layer

Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>

This software is provided 'as-is', without any express or implied

warranty. In no event will the authors be held liable for any damages

arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,

including commercial applications, and to alter it and redistribute it

freely, subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not

claim that you wrote the original software. If you use this software

in a product, an acknowledgment in the product documentation would be

appreciated but is not required.

2. Altered source versions must be plainly marked as such, and must not be

misrepresented as being the original software.

3. This notice may not be removed or altered from any source distribution.

*/

#include "../SDL_internal.h"

#include "SDL_video.h"

#include "SDL_blit.h"

#include "SDL_sysvideo.h"

#include "SDL_endian.h"

/* Functions to blit from 8-bit surfaces to other surfaces */

static void

Blit1to1(SDL_BlitInfo * info)

{

#ifndef USE_DUFFS_LOOP

int c;

#endif

int width, height;

Uint8 *src, *map, *dst;

int srcskip, dstskip;

/* Set up some basic variables */

width = info->dst_w;

height = info->dst_h;

src = info->src;

srcskip = info->src_skip;

dst = info->dst;

dstskip = info->dst_skip;

map = info->table;

while (height--) {

#ifdef USE_DUFFS_LOOP

/* *INDENT-OFF* */

DUFFS_LOOP(

{

*dst = map[*src];

}

dst++;

src++;

, width);

/* *INDENT-ON* */

#else

for (c = width; c; --c) {

*dst = map[*src];

dst++;

src++;

}

#endif

src += srcskip;

dst += dstskip;

}

}

/* This is now endian dependent */

#ifndef USE_DUFFS_LOOP

# if ( SDL_BYTEORDER == SDL_LIL_ENDIAN )

# define HI 1

# define LO 0

# else /* ( SDL_BYTEORDER == SDL_BIG_ENDIAN ) */

# define HI 0

# define LO 1

# endif

#endif

static void

Blit1to2(SDL_BlitInfo * info)

{

#ifndef USE_DUFFS_LOOP

int c;

#endif

int width, height;

Uint8 *src, *dst;

Uint16 *map;

int srcskip, dstskip;

/* Set up some basic variables */

width = info->dst_w;

height = info->dst_h;

src = info->src;

srcskip = info->src_skip;

dst = info->dst;

dstskip = info->dst_skip;

map = (Uint16 *) info->table;

#ifdef USE_DUFFS_LOOP

while (height--) {

/* *INDENT-OFF* */

DUFFS_LOOP(

{

*(Uint16 *)dst = map[*src++];

dst += 2;

},

width);

/* *INDENT-ON* */

src += srcskip;

dst += dstskip;

}

#else

/* Memory align at 4-byte boundary, if necessary */

if ((long) dst & 0x03) {

/* Don't do anything if width is 0 */

if (width == 0) {

return;

}

--width;

while (height--) {

/* Perform copy alignment */

*(Uint16 *) dst = map[*src++];

dst += 2;

/* Copy in 4 pixel chunks */

for (c = width / 4; c; --c) {

*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);

src += 2;

dst += 4;

*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);

src += 2;

dst += 4;

}

/* Get any leftovers */

switch (width & 3) {

case 3:

*(Uint16 *) dst = map[*src++];

dst += 2;

case 2:

*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);

src += 2;

dst += 4;

break;

case 1:

*(Uint16 *) dst = map[*src++];

dst += 2;

break;

}

src += srcskip;

dst += dstskip;

}

} else {

while (height--) {

/* Copy in 4 pixel chunks */

for (c = width / 4; c; --c) {

*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);

src += 2;

dst += 4;

*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);

src += 2;

dst += 4;

}

/* Get any leftovers */

switch (width & 3) {

case 3:

*(Uint16 *) dst = map[*src++];

dst += 2;

case 2:

*(Uint32 *) dst = (map[src[HI]] << 16) | (map[src[LO]]);

src += 2;

dst += 4;

break;

case 1:

*(Uint16 *) dst = map[*src++];

dst += 2;

break;

}

src += srcskip;

dst += dstskip;

}

}

#endif /* USE_DUFFS_LOOP */

}

static void

Blit1to3(SDL_BlitInfo * info)

{

#ifndef USE_DUFFS_LOOP

int c;

#endif

int o;

int width, height;

Uint8 *src, *map, *dst;

int srcskip, dstskip;

/* Set up some basic variables */

width = info->dst_w;

height = info->dst_h;

src = info->src;

srcskip = info->src_skip;

dst = info->dst;

dstskip = info->dst_skip;

map = info->table;

while (height--) {

#ifdef USE_DUFFS_LOOP

/* *INDENT-OFF* */

DUFFS_LOOP(

{

o = *src * 4;

dst[0] = map[o++];

dst[1] = map[o++];

dst[2] = map[o++];

}

src++;

dst += 3;

, width);

/* *INDENT-ON* */

#else

for (c = width; c; --c) {

o = *src * 4;

dst[0] = map[o++];

dst[1] = map[o++];

dst[2] = map[o++];

src++;

dst += 3;

}

#endif /* USE_DUFFS_LOOP */

src += srcskip;

dst += dstskip;

}

}

static void

Blit1to4(SDL_BlitInfo * info)

{

#ifndef USE_DUFFS_LOOP

int c;

#endif

int width, height;

Uint8 *src;

Uint32 *map, *dst;

int srcskip, dstskip;

/* Set up some basic variables */

width = info->dst_w;

height = info->dst_h;

src = info->src;

srcskip = info->src_skip;

dst = (Uint32 *) info->dst;

dstskip = info->dst_skip / 4;

map = (Uint32 *) info->table;

while (height--) {

#ifdef USE_DUFFS_LOOP

/* *INDENT-OFF* */

DUFFS_LOOP(

*dst++ = map[*src++];

, width);

/* *INDENT-ON* */

#else

for (c = width / 4; c; --c) {

*dst++ = map[*src++];

*dst++ = map[*src++];

*dst++ = map[*src++];

*dst++ = map[*src++];

}

switch (width & 3) {

case 3:

*dst++ = map[*src++];

case 2:

*dst++ = map[*src++];

case 1:

*dst++ = map[*src++];

}

#endif /* USE_DUFFS_LOOP */

src += srcskip;

dst += dstskip;

}

}

static void

Blit1to1Key(SDL_BlitInfo * info)

{

int width = info->dst_w;

int height = info->dst_h;

Uint8 *src = info->src;

int srcskip = info->src_skip;

Uint8 *dst = info->dst;

int dstskip = info->dst_skip;

Uint8 *palmap = info->table;

Uint32 ckey = info->colorkey;

if (palmap) {

while (height--) {

/* *INDENT-OFF* */

DUFFS_LOOP(

{

if ( *src != ckey ) {

*dst = palmap[*src];

}

dst++;

src++;

},

width);

/* *INDENT-ON* */

src += srcskip;

dst += dstskip;

}

} else {

while (height--) {

/* *INDENT-OFF* */

DUFFS_LOOP(

{

if ( *src != ckey ) {

*dst = *src;

}

dst++;

src++;

},

width);

/* *INDENT-ON* */

src += srcskip;

dst += dstskip;

}

}

}

static void

Blit1to2Key(SDL_BlitInfo * info)

{

int width = info->dst_w;

int height = info->dst_h;

Uint8 *src = info->src;

int srcskip = info->src_skip;

Uint16 *dstp = (Uint16 *) info->dst;

int dstskip = info->dst_skip;

Uint16 *palmap = (Uint16 *) info->table;

Uint32 ckey = info->colorkey;

/* Set up some basic variables */

dstskip /= 2;

while (height--) {

/* *INDENT-OFF* */

DUFFS_LOOP(

{

if ( *src != ckey ) {

*dstp=palmap[*src];

}

src++;

dstp++;

},

width);

/* *INDENT-ON* */

src += srcskip;

dstp += dstskip;

}

}

static void

Blit1to3Key(SDL_BlitInfo * info)

{

int width = info->dst_w;

int height = info->dst_h;

Uint8 *src = info->src;

int srcskip = info->src_skip;

Uint8 *dst = info->dst;

int dstskip = info->dst_skip;

Uint8 *palmap = info->table;

Uint32 ckey = info->colorkey;

int o;

while (height--) {

/* *INDENT-OFF* */

DUFFS_LOOP(

{

if ( *src != ckey ) {

o = *src * 4;

dst[0] = palmap[o++];

dst[1] = palmap[o++];

dst[2] = palmap[o++];

}

src++;

dst += 3;

},

width);

/* *INDENT-ON* */

src += srcskip;

dst += dstskip;

}

}

static void

Blit1to4Key(SDL_BlitInfo * info)

{

int width = info->dst_w;

int height = info->dst_h;

Uint8 *src = info->src;

int srcskip = info->src_skip;

Uint32 *dstp = (Uint32 *) info->dst;

int dstskip = info->dst_skip;

Uint32 *palmap = (Uint32 *) info->table;

Uint32 ckey = info->colorkey;

/* Set up some basic variables */

dstskip /= 4;

while (height--) {

/* *INDENT-OFF* */

DUFFS_LOOP(

{

if ( *src != ckey ) {

*dstp = palmap[*src];

}

src++;

dstp++;

},

width);

/* *INDENT-ON* */

src += srcskip;

dstp += dstskip;

}

}

static void

Blit1toNAlpha(SDL_BlitInfo * info)

{

int width = info->dst_w;

int height = info->dst_h;

Uint8 *src = info->src;

int srcskip = info->src_skip;

Uint8 *dst = info->dst;

int dstskip = info->dst_skip;

SDL_PixelFormat *dstfmt = info->dst_fmt;

const SDL_Color *srcpal = info->src_fmt->palette->colors;

int dstbpp;

Uint32 pixel;

unsigned sR, sG, sB;

unsigned dR, dG, dB, dA;

const unsigned A = info->a;

/* Set up some basic variables */

dstbpp = dstfmt->BytesPerPixel;

while (height--) {

/* *INDENT-OFF* */

DUFFS_LOOP4(

{

sR = srcpal[*src].r;

sG = srcpal[*src].g;

sB = srcpal[*src].b;

DISEMBLE_RGBA(dst, dstbpp, dstfmt, pixel, dR, dG, dB, dA);

ALPHA_BLEND_RGBA(sR, sG, sB, A, dR, dG, dB, dA);

ASSEMBLE_RGBA(dst, dstbpp, dstfmt, dR, dG, dB, dA);

src++;

dst += dstbpp;

},

width);

/* *INDENT-ON* */

src += srcskip;

dst += dstskip;

}

}

static void

Blit1toNAlphaKey(SDL_BlitInfo * info)

{

int width = info->dst_w;

int height = info->dst_h;

Uint8 *src = info->src;

int srcskip = info->src_skip;

Uint8 *dst = info->dst;

int dstskip = info->dst_skip;

SDL_PixelFormat *dstfmt = info->dst_fmt;

const SDL_Color *srcpal = info->src_fmt->palette->colors;

Uint32 ckey = info->colorkey;

int dstbpp;

Uint32 pixel;

unsigned sR, sG, sB;

unsigned dR, dG, dB, dA;

const unsigned A = info->a;

/* Set up some basic variables */

dstbpp = dstfmt->BytesPerPixel;

while (height--) {

/* *INDENT-OFF* */

DUFFS_LOOP(

{

if ( *src != ckey ) {

sR = srcpal[*src].r;

sG = srcpal[*src].g;

sB = srcpal[*src].b;

DISEMBLE_RGBA(dst, dstbpp, dstfmt, pixel, dR, dG, dB, dA);

ALPHA_BLEND_RGBA(sR, sG, sB, A, dR, dG, dB, dA);

ASSEMBLE_RGBA(dst, dstbpp, dstfmt, dR, dG, dB, dA);

}

src++;

dst += dstbpp;

},

width);

/* *INDENT-ON* */

src += srcskip;

dst += dstskip;

}

}

static const SDL_BlitFunc one_blit[] = {

(SDL_BlitFunc) NULL, Blit1to1, Blit1to2, Blit1to3, Blit1to4

};

static const SDL_BlitFunc one_blitkey[] = {

(SDL_BlitFunc) NULL, Blit1to1Key, Blit1to2Key, Blit1to3Key, Blit1to4Key

};

SDL_BlitFunc

SDL_CalculateBlit1(SDL_Surface * surface)

{

int which;

SDL_PixelFormat *dstfmt;

dstfmt = surface->map->dst->format;

if (dstfmt->BitsPerPixel < 8) {

which = 0;

} else {

which = dstfmt->BytesPerPixel;

}

switch (surface->map->info.flags & ~SDL_COPY_RLE_MASK) {

case 0:

return one_blit[which];

case SDL_COPY_COLORKEY:

return one_blitkey[which];

case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:

/* Supporting 8bpp->8bpp alpha is doable but requires lots of

tables which consume space and takes time to precompute,

so is better left to the user */

return which >= 2 ? Blit1toNAlpha : (SDL_BlitFunc) NULL;

case SDL_COPY_COLORKEY | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:

return which >= 2 ? Blit1toNAlphaKey : (SDL_BlitFunc) NULL;

}

return (SDL_BlitFunc) NULL;

}

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