cscg22-gearboy

CSCG 2022 Challenge 'Gearboy'
git clone https://git.sinitax.com/sinitax/cscg22-gearboy
Log | Files | Refs | sfeed.txt

SDL_blit.h (31045B)


      1/*
      2  Simple DirectMedia Layer
      3  Copyright (C) 1997-2014 Sam Lantinga <slouken@libsdl.org>
      4
      5  This software is provided 'as-is', without any express or implied
      6  warranty.  In no event will the authors be held liable for any damages
      7  arising from the use of this software.
      8
      9  Permission is granted to anyone to use this software for any purpose,
     10  including commercial applications, and to alter it and redistribute it
     11  freely, subject to the following restrictions:
     12
     13  1. The origin of this software must not be misrepresented; you must not
     14     claim that you wrote the original software. If you use this software
     15     in a product, an acknowledgment in the product documentation would be
     16     appreciated but is not required.
     17  2. Altered source versions must be plainly marked as such, and must not be
     18     misrepresented as being the original software.
     19  3. This notice may not be removed or altered from any source distribution.
     20*/
     21#include "../SDL_internal.h"
     22
     23#ifndef _SDL_blit_h
     24#define _SDL_blit_h
     25
     26#include "SDL_cpuinfo.h"
     27#include "SDL_endian.h"
     28#include "SDL_surface.h"
     29
     30/* Table to do pixel byte expansion */
     31extern Uint8* SDL_expand_byte[9];
     32
     33/* SDL blit copy flags */
     34#define SDL_COPY_MODULATE_COLOR     0x00000001
     35#define SDL_COPY_MODULATE_ALPHA     0x00000002
     36#define SDL_COPY_BLEND              0x00000010
     37#define SDL_COPY_ADD                0x00000020
     38#define SDL_COPY_MOD                0x00000040
     39#define SDL_COPY_COLORKEY           0x00000100
     40#define SDL_COPY_NEAREST            0x00000200
     41#define SDL_COPY_RLE_DESIRED        0x00001000
     42#define SDL_COPY_RLE_COLORKEY       0x00002000
     43#define SDL_COPY_RLE_ALPHAKEY       0x00004000
     44#define SDL_COPY_RLE_MASK           (SDL_COPY_RLE_DESIRED|SDL_COPY_RLE_COLORKEY|SDL_COPY_RLE_ALPHAKEY)
     45
     46/* SDL blit CPU flags */
     47#define SDL_CPU_ANY                 0x00000000
     48#define SDL_CPU_MMX                 0x00000001
     49#define SDL_CPU_3DNOW               0x00000002
     50#define SDL_CPU_SSE                 0x00000004
     51#define SDL_CPU_SSE2                0x00000008
     52#define SDL_CPU_ALTIVEC_PREFETCH    0x00000010
     53#define SDL_CPU_ALTIVEC_NOPREFETCH  0x00000020
     54
     55typedef struct
     56{
     57    Uint8 *src;
     58    int src_w, src_h;
     59    int src_pitch;
     60    int src_skip;
     61    Uint8 *dst;
     62    int dst_w, dst_h;
     63    int dst_pitch;
     64    int dst_skip;
     65    SDL_PixelFormat *src_fmt;
     66    SDL_PixelFormat *dst_fmt;
     67    Uint8 *table;
     68    int flags;
     69    Uint32 colorkey;
     70    Uint8 r, g, b, a;
     71} SDL_BlitInfo;
     72
     73typedef void (SDLCALL * SDL_BlitFunc) (SDL_BlitInfo * info);
     74
     75typedef struct
     76{
     77    Uint32 src_format;
     78    Uint32 dst_format;
     79    int flags;
     80    int cpu;
     81    SDL_BlitFunc func;
     82} SDL_BlitFuncEntry;
     83
     84/* Blit mapping definition */
     85typedef struct SDL_BlitMap
     86{
     87    SDL_Surface *dst;
     88    int identity;
     89    SDL_blit blit;
     90    void *data;
     91    SDL_BlitInfo info;
     92
     93    /* the version count matches the destination; mismatch indicates
     94       an invalid mapping */
     95    Uint32 dst_palette_version;
     96    Uint32 src_palette_version;
     97} SDL_BlitMap;
     98
     99/* Functions found in SDL_blit.c */
    100extern int SDL_CalculateBlit(SDL_Surface * surface);
    101
    102/* Functions found in SDL_blit_*.c */
    103extern SDL_BlitFunc SDL_CalculateBlit0(SDL_Surface * surface);
    104extern SDL_BlitFunc SDL_CalculateBlit1(SDL_Surface * surface);
    105extern SDL_BlitFunc SDL_CalculateBlitN(SDL_Surface * surface);
    106extern SDL_BlitFunc SDL_CalculateBlitA(SDL_Surface * surface);
    107
    108/*
    109 * Useful macros for blitting routines
    110 */
    111
    112#if defined(__GNUC__)
    113#define DECLARE_ALIGNED(t,v,a)  t __attribute__((aligned(a))) v
    114#elif defined(_MSC_VER)
    115#define DECLARE_ALIGNED(t,v,a)  __declspec(align(a)) t v
    116#else
    117#define DECLARE_ALIGNED(t,v,a)  t v
    118#endif
    119
    120/* Load pixel of the specified format from a buffer and get its R-G-B values */
    121#define RGB_FROM_PIXEL(Pixel, fmt, r, g, b)                             \
    122{                                                                       \
    123    r = SDL_expand_byte[fmt->Rloss][((Pixel&fmt->Rmask)>>fmt->Rshift)]; \
    124    g = SDL_expand_byte[fmt->Gloss][((Pixel&fmt->Gmask)>>fmt->Gshift)]; \
    125    b = SDL_expand_byte[fmt->Bloss][((Pixel&fmt->Bmask)>>fmt->Bshift)]; \
    126}
    127#define RGB_FROM_RGB565(Pixel, r, g, b)                                 \
    128    {                                                                   \
    129    r = SDL_expand_byte[3][((Pixel&0xF800)>>11)];                       \
    130    g = SDL_expand_byte[2][((Pixel&0x07E0)>>5)];                        \
    131    b = SDL_expand_byte[3][(Pixel&0x001F)];                             \
    132}
    133#define RGB_FROM_RGB555(Pixel, r, g, b)                                 \
    134{                                                                       \
    135    r = SDL_expand_byte[3][((Pixel&0x7C00)>>10)];                       \
    136    g = SDL_expand_byte[3][((Pixel&0x03E0)>>5)];                        \
    137    b = SDL_expand_byte[3][(Pixel&0x001F)];                             \
    138}
    139#define RGB_FROM_RGB888(Pixel, r, g, b)                                 \
    140{                                                                       \
    141    r = ((Pixel&0xFF0000)>>16);                                         \
    142    g = ((Pixel&0xFF00)>>8);                                            \
    143    b = (Pixel&0xFF);                                                   \
    144}
    145#define RETRIEVE_RGB_PIXEL(buf, bpp, Pixel)                             \
    146do {                                                                    \
    147    switch (bpp) {                                                      \
    148        case 1:                                                         \
    149            Pixel = *((Uint8 *)(buf));                                  \
    150        break;                                                          \
    151                                                                        \
    152        case 2:                                                         \
    153            Pixel = *((Uint16 *)(buf));                                 \
    154        break;                                                          \
    155                                                                        \
    156        case 3: {                                                       \
    157            Uint8 *B = (Uint8 *)(buf);                                  \
    158            if (SDL_BYTEORDER == SDL_LIL_ENDIAN) {                      \
    159                Pixel = B[0] + (B[1] << 8) + (B[2] << 16);              \
    160            } else {                                                    \
    161                Pixel = (B[0] << 16) + (B[1] << 8) + B[2];              \
    162            }                                                           \
    163        }                                                               \
    164        break;                                                          \
    165                                                                        \
    166        case 4:                                                         \
    167            Pixel = *((Uint32 *)(buf));                                 \
    168        break;                                                          \
    169                                                                        \
    170        default:                                                        \
    171                Pixel = 0; /* stop gcc complaints */                    \
    172        break;                                                          \
    173    }                                                                   \
    174} while (0)
    175
    176#define DISEMBLE_RGB(buf, bpp, fmt, Pixel, r, g, b)                     \
    177do {                                                                    \
    178    switch (bpp) {                                                      \
    179        case 1:                                                         \
    180            Pixel = *((Uint8 *)(buf));                                  \
    181            RGB_FROM_PIXEL(Pixel, fmt, r, g, b);                        \
    182        break;                                                          \
    183                                                                        \
    184        case 2:                                                         \
    185            Pixel = *((Uint16 *)(buf));                                 \
    186            RGB_FROM_PIXEL(Pixel, fmt, r, g, b);                        \
    187        break;                                                          \
    188                                                                        \
    189        case 3: {                                                       \
    190            Pixel = 0;                                                  \
    191            if (SDL_BYTEORDER == SDL_LIL_ENDIAN) {                      \
    192                r = *((buf)+fmt->Rshift/8);                             \
    193                g = *((buf)+fmt->Gshift/8);                             \
    194                b = *((buf)+fmt->Bshift/8);                             \
    195            } else {                                                    \
    196                r = *((buf)+2-fmt->Rshift/8);                           \
    197                g = *((buf)+2-fmt->Gshift/8);                           \
    198                b = *((buf)+2-fmt->Bshift/8);                           \
    199            }                                                           \
    200        }                                                               \
    201        break;                                                          \
    202                                                                        \
    203        case 4:                                                         \
    204            Pixel = *((Uint32 *)(buf));                                 \
    205            RGB_FROM_PIXEL(Pixel, fmt, r, g, b);                        \
    206        break;                                                          \
    207                                                                        \
    208        default:                                                        \
    209                /* stop gcc complaints */                               \
    210                Pixel = 0;                                              \
    211                r = g = b = 0;                                          \
    212        break;                                                          \
    213    }                                                                   \
    214} while (0)
    215
    216/* Assemble R-G-B values into a specified pixel format and store them */
    217#define PIXEL_FROM_RGB(Pixel, fmt, r, g, b)                             \
    218{                                                                       \
    219    Pixel = ((r>>fmt->Rloss)<<fmt->Rshift)|                             \
    220        ((g>>fmt->Gloss)<<fmt->Gshift)|                                 \
    221        ((b>>fmt->Bloss)<<fmt->Bshift)|                                 \
    222        fmt->Amask;                                                     \
    223}
    224#define RGB565_FROM_RGB(Pixel, r, g, b)                                 \
    225{                                                                       \
    226    Pixel = ((r>>3)<<11)|((g>>2)<<5)|(b>>3);                            \
    227}
    228#define RGB555_FROM_RGB(Pixel, r, g, b)                                 \
    229{                                                                       \
    230    Pixel = ((r>>3)<<10)|((g>>3)<<5)|(b>>3);                            \
    231}
    232#define RGB888_FROM_RGB(Pixel, r, g, b)                                 \
    233{                                                                       \
    234    Pixel = (r<<16)|(g<<8)|b;                                           \
    235}
    236#define ARGB8888_FROM_RGBA(Pixel, r, g, b, a)                           \
    237{                                                                       \
    238    Pixel = (a<<24)|(r<<16)|(g<<8)|b;                                   \
    239}
    240#define RGBA8888_FROM_RGBA(Pixel, r, g, b, a)                           \
    241{                                                                       \
    242    Pixel = (r<<24)|(g<<16)|(b<<8)|a;                                   \
    243}
    244#define ABGR8888_FROM_RGBA(Pixel, r, g, b, a)                           \
    245{                                                                       \
    246    Pixel = (a<<24)|(b<<16)|(g<<8)|r;                                   \
    247}
    248#define BGRA8888_FROM_RGBA(Pixel, r, g, b, a)                           \
    249{                                                                       \
    250    Pixel = (b<<24)|(g<<16)|(r<<8)|a;                                   \
    251}
    252#define ARGB2101010_FROM_RGBA(Pixel, r, g, b, a)                        \
    253{                                                                       \
    254    r = r ? ((r << 2) | 0x3) : 0;                                       \
    255    g = g ? ((g << 2) | 0x3) : 0;                                       \
    256    b = b ? ((b << 2) | 0x3) : 0;                                       \
    257    a = (a * 3) / 255;                                                  \
    258    Pixel = (a<<30)|(r<<20)|(g<<10)|b;                                  \
    259}
    260#define ASSEMBLE_RGB(buf, bpp, fmt, r, g, b)                            \
    261{                                                                       \
    262    switch (bpp) {                                                      \
    263        case 1: {                                                       \
    264            Uint8 Pixel;                                                \
    265                                                                        \
    266            PIXEL_FROM_RGB(Pixel, fmt, r, g, b);                        \
    267            *((Uint8 *)(buf)) = Pixel;                                  \
    268        }                                                               \
    269        break;                                                          \
    270                                                                        \
    271        case 2: {                                                       \
    272            Uint16 Pixel;                                               \
    273                                                                        \
    274            PIXEL_FROM_RGB(Pixel, fmt, r, g, b);                        \
    275            *((Uint16 *)(buf)) = Pixel;                                 \
    276        }                                                               \
    277        break;                                                          \
    278                                                                        \
    279        case 3: {                                                       \
    280            if (SDL_BYTEORDER == SDL_LIL_ENDIAN) {                      \
    281                *((buf)+fmt->Rshift/8) = r;                             \
    282                *((buf)+fmt->Gshift/8) = g;                             \
    283                *((buf)+fmt->Bshift/8) = b;                             \
    284            } else {                                                    \
    285                *((buf)+2-fmt->Rshift/8) = r;                           \
    286                *((buf)+2-fmt->Gshift/8) = g;                           \
    287                *((buf)+2-fmt->Bshift/8) = b;                           \
    288            }                                                           \
    289        }                                                               \
    290        break;                                                          \
    291                                                                        \
    292        case 4: {                                                       \
    293            Uint32 Pixel;                                               \
    294                                                                        \
    295            PIXEL_FROM_RGB(Pixel, fmt, r, g, b);                        \
    296            *((Uint32 *)(buf)) = Pixel;                                 \
    297        }                                                               \
    298        break;                                                          \
    299    }                                                                   \
    300}
    301
    302/* FIXME: Should we rescale alpha into 0..255 here? */
    303#define RGBA_FROM_PIXEL(Pixel, fmt, r, g, b, a)                         \
    304{                                                                       \
    305    r = SDL_expand_byte[fmt->Rloss][((Pixel&fmt->Rmask)>>fmt->Rshift)]; \
    306    g = SDL_expand_byte[fmt->Gloss][((Pixel&fmt->Gmask)>>fmt->Gshift)]; \
    307    b = SDL_expand_byte[fmt->Bloss][((Pixel&fmt->Bmask)>>fmt->Bshift)]; \
    308    a = SDL_expand_byte[fmt->Aloss][((Pixel&fmt->Amask)>>fmt->Ashift)]; \
    309}
    310#define RGBA_FROM_8888(Pixel, fmt, r, g, b, a)                          \
    311{                                                                       \
    312    r = (Pixel&fmt->Rmask)>>fmt->Rshift;                                \
    313    g = (Pixel&fmt->Gmask)>>fmt->Gshift;                                \
    314    b = (Pixel&fmt->Bmask)>>fmt->Bshift;                                \
    315    a = (Pixel&fmt->Amask)>>fmt->Ashift;                                \
    316}
    317#define RGBA_FROM_RGBA8888(Pixel, r, g, b, a)                           \
    318{                                                                       \
    319    r = (Pixel>>24);                                                    \
    320    g = ((Pixel>>16)&0xFF);                                             \
    321    b = ((Pixel>>8)&0xFF);                                              \
    322    a = (Pixel&0xFF);                                                   \
    323}
    324#define RGBA_FROM_ARGB8888(Pixel, r, g, b, a)                           \
    325{                                                                       \
    326    r = ((Pixel>>16)&0xFF);                                             \
    327    g = ((Pixel>>8)&0xFF);                                              \
    328    b = (Pixel&0xFF);                                                   \
    329    a = (Pixel>>24);                                                    \
    330}
    331#define RGBA_FROM_ABGR8888(Pixel, r, g, b, a)                           \
    332{                                                                       \
    333    r = (Pixel&0xFF);                                                   \
    334    g = ((Pixel>>8)&0xFF);                                              \
    335    b = ((Pixel>>16)&0xFF);                                             \
    336    a = (Pixel>>24);                                                    \
    337}
    338#define RGBA_FROM_BGRA8888(Pixel, r, g, b, a)                           \
    339{                                                                       \
    340    r = ((Pixel>>8)&0xFF);                                              \
    341    g = ((Pixel>>16)&0xFF);                                             \
    342    b = (Pixel>>24);                                                    \
    343    a = (Pixel&0xFF);                                                   \
    344}
    345#define RGBA_FROM_ARGB2101010(Pixel, r, g, b, a)                        \
    346{                                                                       \
    347    r = ((Pixel>>22)&0xFF);                                             \
    348    g = ((Pixel>>12)&0xFF);                                             \
    349    b = ((Pixel>>2)&0xFF);                                              \
    350    a = SDL_expand_byte[6][(Pixel>>30)];                                \
    351}
    352#define DISEMBLE_RGBA(buf, bpp, fmt, Pixel, r, g, b, a)                 \
    353do {                                                                    \
    354    switch (bpp) {                                                      \
    355        case 1:                                                         \
    356            Pixel = *((Uint8 *)(buf));                                  \
    357            RGBA_FROM_PIXEL(Pixel, fmt, r, g, b, a);                    \
    358        break;                                                          \
    359                                                                        \
    360        case 2:                                                         \
    361            Pixel = *((Uint16 *)(buf));                                 \
    362            RGBA_FROM_PIXEL(Pixel, fmt, r, g, b, a);                    \
    363        break;                                                          \
    364                                                                        \
    365        case 3: {                                                       \
    366            Pixel = 0;                                                  \
    367            if (SDL_BYTEORDER == SDL_LIL_ENDIAN) {                      \
    368                r = *((buf)+fmt->Rshift/8);                             \
    369                g = *((buf)+fmt->Gshift/8);                             \
    370                b = *((buf)+fmt->Bshift/8);                             \
    371            } else {                                                    \
    372                r = *((buf)+2-fmt->Rshift/8);                           \
    373                g = *((buf)+2-fmt->Gshift/8);                           \
    374                b = *((buf)+2-fmt->Bshift/8);                           \
    375            }                                                           \
    376            a = 0xFF;                                                   \
    377        }                                                               \
    378        break;                                                          \
    379                                                                        \
    380        case 4:                                                         \
    381            Pixel = *((Uint32 *)(buf));                                 \
    382            RGBA_FROM_PIXEL(Pixel, fmt, r, g, b, a);                    \
    383        break;                                                          \
    384                                                                        \
    385        default:                                                        \
    386            /* stop gcc complaints */                                   \
    387            Pixel = 0;                                                  \
    388            r = g = b = a = 0;                                          \
    389        break;                                                          \
    390    }                                                                   \
    391} while (0)
    392
    393/* FIXME: this isn't correct, especially for Alpha (maximum != 255) */
    394#define PIXEL_FROM_RGBA(Pixel, fmt, r, g, b, a)                         \
    395{                                                                       \
    396    Pixel = ((r>>fmt->Rloss)<<fmt->Rshift)|                             \
    397        ((g>>fmt->Gloss)<<fmt->Gshift)|                                 \
    398        ((b>>fmt->Bloss)<<fmt->Bshift)|                                 \
    399        ((a>>fmt->Aloss)<<fmt->Ashift);                                 \
    400}
    401#define ASSEMBLE_RGBA(buf, bpp, fmt, r, g, b, a)                        \
    402{                                                                       \
    403    switch (bpp) {                                                      \
    404        case 1: {                                                       \
    405            Uint8 _pixel;                                               \
    406                                                                        \
    407            PIXEL_FROM_RGBA(_pixel, fmt, r, g, b, a);                   \
    408            *((Uint8 *)(buf)) = _pixel;                                 \
    409        }                                                               \
    410        break;                                                          \
    411                                                                        \
    412        case 2: {                                                       \
    413            Uint16 _pixel;                                              \
    414                                                                        \
    415            PIXEL_FROM_RGBA(_pixel, fmt, r, g, b, a);                   \
    416            *((Uint16 *)(buf)) = _pixel;                                \
    417        }                                                               \
    418        break;                                                          \
    419                                                                        \
    420        case 3: {                                                       \
    421            if (SDL_BYTEORDER == SDL_LIL_ENDIAN) {                      \
    422                *((buf)+fmt->Rshift/8) = r;                             \
    423                *((buf)+fmt->Gshift/8) = g;                             \
    424                *((buf)+fmt->Bshift/8) = b;                             \
    425            } else {                                                    \
    426                *((buf)+2-fmt->Rshift/8) = r;                           \
    427                *((buf)+2-fmt->Gshift/8) = g;                           \
    428                *((buf)+2-fmt->Bshift/8) = b;                           \
    429            }                                                           \
    430        }                                                               \
    431        break;                                                          \
    432                                                                        \
    433        case 4: {                                                       \
    434            Uint32 _pixel;                                              \
    435                                                                        \
    436            PIXEL_FROM_RGBA(_pixel, fmt, r, g, b, a);                   \
    437            *((Uint32 *)(buf)) = _pixel;                                \
    438        }                                                               \
    439        break;                                                          \
    440    }                                                                   \
    441}
    442
    443/* Blend the RGB values of two pixels with an alpha value */
    444#define ALPHA_BLEND_RGB(sR, sG, sB, A, dR, dG, dB)                      \
    445do {                                                                    \
    446    dR = ((((unsigned)(sR-dR)*(unsigned)A)/255)+dR);                    \
    447    dG = ((((unsigned)(sG-dG)*(unsigned)A)/255)+dG);                    \
    448    dB = ((((unsigned)(sB-dB)*(unsigned)A)/255)+dB);                    \
    449} while(0)
    450
    451
    452/* Blend the RGBA values of two pixels */
    453#define ALPHA_BLEND_RGBA(sR, sG, sB, sA, dR, dG, dB, dA)                \
    454do {                                                                    \
    455    dR = ((((unsigned)(sR-dR)*(unsigned)sA)/255)+dR);                   \
    456    dG = ((((unsigned)(sG-dG)*(unsigned)sA)/255)+dG);                   \
    457    dB = ((((unsigned)(sB-dB)*(unsigned)sA)/255)+dB);                   \
    458    dA = ((unsigned)sA+(unsigned)dA-((unsigned)sA*dA)/255);             \
    459} while(0)
    460
    461
    462/* This is a very useful loop for optimizing blitters */
    463#if defined(_MSC_VER) && (_MSC_VER == 1300)
    464/* There's a bug in the Visual C++ 7 optimizer when compiling this code */
    465#else
    466#define USE_DUFFS_LOOP
    467#endif
    468#ifdef USE_DUFFS_LOOP
    469
    470/* 8-times unrolled loop */
    471#define DUFFS_LOOP8(pixel_copy_increment, width)                        \
    472{ int n = (width+7)/8;                                                  \
    473    switch (width & 7) {                                                \
    474    case 0: do {    pixel_copy_increment;                               \
    475    case 7:     pixel_copy_increment;                                   \
    476    case 6:     pixel_copy_increment;                                   \
    477    case 5:     pixel_copy_increment;                                   \
    478    case 4:     pixel_copy_increment;                                   \
    479    case 3:     pixel_copy_increment;                                   \
    480    case 2:     pixel_copy_increment;                                   \
    481    case 1:     pixel_copy_increment;                                   \
    482        } while ( --n > 0 );                                            \
    483    }                                                                   \
    484}
    485
    486/* 4-times unrolled loop */
    487#define DUFFS_LOOP4(pixel_copy_increment, width)                        \
    488{ int n = (width+3)/4;                                                  \
    489    switch (width & 3) {                                                \
    490    case 0: do {    pixel_copy_increment;                               \
    491    case 3:     pixel_copy_increment;                                   \
    492    case 2:     pixel_copy_increment;                                   \
    493    case 1:     pixel_copy_increment;                                   \
    494        } while (--n > 0);                                              \
    495    }                                                                   \
    496}
    497
    498/* Use the 8-times version of the loop by default */
    499#define DUFFS_LOOP(pixel_copy_increment, width)                         \
    500    DUFFS_LOOP8(pixel_copy_increment, width)
    501
    502/* Special version of Duff's device for even more optimization */
    503#define DUFFS_LOOP_124(pixel_copy_increment1,                           \
    504                       pixel_copy_increment2,                           \
    505                       pixel_copy_increment4, width)                    \
    506{ int n = width;                                                        \
    507    if (n & 1) {                                                        \
    508        pixel_copy_increment1; n -= 1;                                  \
    509    }                                                                   \
    510    if (n & 2) {                                                        \
    511        pixel_copy_increment2; n -= 2;                                  \
    512    }                                                                   \
    513    if (n & 4) {                                                        \
    514        pixel_copy_increment4; n -= 4;                                  \
    515    }                                                                   \
    516    if (n) {                                                            \
    517        n /= 8;                                                         \
    518        do {                                                            \
    519            pixel_copy_increment4;                                      \
    520            pixel_copy_increment4;                                      \
    521        } while (--n > 0);                                              \
    522    }                                                                   \
    523}
    524
    525#else
    526
    527/* Don't use Duff's device to unroll loops */
    528#define DUFFS_LOOP(pixel_copy_increment, width)                         \
    529{ int n;                                                                \
    530    for ( n=width; n > 0; --n ) {                                       \
    531        pixel_copy_increment;                                           \
    532    }                                                                   \
    533}
    534#define DUFFS_LOOP8(pixel_copy_increment, width)                        \
    535    DUFFS_LOOP(pixel_copy_increment, width)
    536#define DUFFS_LOOP4(pixel_copy_increment, width)                        \
    537    DUFFS_LOOP(pixel_copy_increment, width)
    538#define DUFFS_LOOP_124(pixel_copy_increment1,                           \
    539                       pixel_copy_increment2,                           \
    540                       pixel_copy_increment4, width)                    \
    541    DUFFS_LOOP(pixel_copy_increment1, width)
    542
    543#endif /* USE_DUFFS_LOOP */
    544
    545/* Prevent Visual C++ 6.0 from printing out stupid warnings */
    546#if defined(_MSC_VER) && (_MSC_VER >= 600)
    547#pragma warning(disable: 4550)
    548#endif
    549
    550#endif /* _SDL_blit_h */
    551
    552/* vi: set ts=4 sw=4 expandtab: */