SDL_blit.c File Reference

#include "../SDL_internal.h"
#include "SDL_video.h"
#include "SDL_sysvideo.h"
#include "SDL_blit.h"
#include "SDL_blit_auto.h"
#include "SDL_blit_copy.h"
#include "SDL_blit_slow.h"
#include "SDL_RLEaccel_c.h"
#include "SDL_pixels_c.h"

Include dependency graph for SDL_blit.c:

Go to the source code of this file.

Functions
static int	SDL_SoftBlit (SDL_Surface *src, SDL_Rect *srcrect, SDL_Surface *dst, SDL_Rect *dstrect)
static SDL_bool	SDL_UseAltivecPrefetch ()
static SDL_BlitFunc	SDL_ChooseBlitFunc (Uint32 src_format, Uint32 dst_format, int flags, SDL_BlitFuncEntry *entries)
int	SDL_CalculateBlit (SDL_Surface *surface)

Function Documentation

SDL_CalculateBlit()

int SDL_CalculateBlit

(

SDL_Surface *

surface

)

Definition at line 196 of file SDL_blit.c.

{
    SDL_BlitFunc blit = NULL;
    SDL_BlitMap *map = surface->map;
    SDL_Surface *dst = map->dst;
 
    /* We don't currently support blitting to < 8 bpp surfaces */
    if (dst->format->BitsPerPixel < 8) {
        SDL_InvalidateMap(map);
        return SDL_SetError("Blit combination not supported");
    }
 
#if SDL_HAVE_RLE
    /* Clean everything out to start */
    if ((surface->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
        SDL_UnRLESurface(surface, 1);
    }
#endif
 
    map->blit = SDL_SoftBlit;
    map->info.src_fmt = surface->format;
    map->info.src_pitch = surface->pitch;
    map->info.dst_fmt = dst->format;
    map->info.dst_pitch = dst->pitch;
 
#if SDL_HAVE_RLE
    /* See if we can do RLE acceleration */
    if (map->info.flags & SDL_COPY_RLE_DESIRED) {
        if (SDL_RLESurface(surface) == 0) {
            return 0;
        }
    }
#endif
 
    /* Choose a standard blit function */
    if (map->identity && !(map->info.flags & ~SDL_COPY_RLE_DESIRED)) {
        blit = SDL_BlitCopy;
    } else if (surface->format->Rloss > 8 || dst->format->Rloss > 8) {
        /* Greater than 8 bits per channel not supported yet */
        SDL_InvalidateMap(map);
        return SDL_SetError("Blit combination not supported");
    }
#if SDL_HAVE_BLIT_0
    else if (surface->format->BitsPerPixel < 8 &&
               SDL_ISPIXELFORMAT_INDEXED(surface->format->format)) {
        blit = SDL_CalculateBlit0(surface);
    }
#endif
#if SDL_HAVE_BLIT_1
    else if (surface->format->BytesPerPixel == 1 &&
               SDL_ISPIXELFORMAT_INDEXED(surface->format->format)) {
        blit = SDL_CalculateBlit1(surface);
    }
#endif
#if SDL_HAVE_BLIT_A
    else if (map->info.flags & SDL_COPY_BLEND) {
        blit = SDL_CalculateBlitA(surface);
    }
#endif
#if SDL_HAVE_BLIT_N
    else {
        blit = SDL_CalculateBlitN(surface);
    }
#endif
#if SDL_HAVE_BLIT_AUTO
    if (blit == NULL) {
        Uint32 src_format = surface->format->format;
        Uint32 dst_format = dst->format->format;
 
        blit =
            SDL_ChooseBlitFunc(src_format, dst_format, map->info.flags,
                               SDL_GeneratedBlitFuncTable);
    }
#endif
 
#ifndef TEST_SLOW_BLIT
    if (blit == NULL)
#endif
    {
        Uint32 src_format = surface->format->format;
        Uint32 dst_format = dst->format->format;
 
        if (!SDL_ISPIXELFORMAT_INDEXED(src_format) &&
            !SDL_ISPIXELFORMAT_FOURCC(src_format) &&
            !SDL_ISPIXELFORMAT_INDEXED(dst_format) &&
            !SDL_ISPIXELFORMAT_FOURCC(dst_format)) {
            blit = SDL_Blit_Slow;
        }
    }
    map->data = blit;
 
    /* Make sure we have a blit function */
    if (blit == NULL) {
        SDL_InvalidateMap(map);
        return SDL_SetError("Blit combination not supported");
    }
 
    return 0;
}

References map, NULL, SDL_Blit_Slow(), SDL_BlitCopy(), SDL_CalculateBlit0(), SDL_CalculateBlit1(), SDL_CalculateBlitA(), SDL_CalculateBlitN(), SDL_ChooseBlitFunc(), SDL_COPY_BLEND, SDL_COPY_RLE_DESIRED, SDL_GeneratedBlitFuncTable, SDL_InvalidateMap(), SDL_ISPIXELFORMAT_FOURCC, SDL_ISPIXELFORMAT_INDEXED, SDL_RLEACCEL, SDL_RLESurface(), SDL_SetError, SDL_SoftBlit(), and SDL_UnRLESurface().

Referenced by SDL_MapSurface().

SDL_ChooseBlitFunc()

static SDL_BlitFunc SDL_ChooseBlitFunc ( Uint32  src_format, Uint32  dst_format, int  flags, SDL_BlitFuncEntry *  entries  )

static

Definition at line 130 of file SDL_blit.c.

{
    int i, flagcheck = (flags & (SDL_COPY_MODULATE_COLOR | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND | SDL_COPY_ADD | SDL_COPY_MOD | SDL_COPY_MUL | SDL_COPY_COLORKEY | SDL_COPY_NEAREST));
    static int features = 0x7fffffff;
 
    /* Get the available CPU features */
    if (features == 0x7fffffff) {
        const char *override = SDL_getenv("SDL_BLIT_CPU_FEATURES");
 
        features = SDL_CPU_ANY;
 
        /* Allow an override for testing .. */
        if (override) {
            SDL_sscanf(override, "%u", &features);
        } else {
            if (SDL_HasMMX()) {
                features |= SDL_CPU_MMX;
            }
            if (SDL_Has3DNow()) {
                features |= SDL_CPU_3DNOW;
            }
            if (SDL_HasSSE()) {
                features |= SDL_CPU_SSE;
            }
            if (SDL_HasSSE2()) {
                features |= SDL_CPU_SSE2;
            }
            if (SDL_HasAltiVec()) {
                if (SDL_UseAltivecPrefetch()) {
                    features |= SDL_CPU_ALTIVEC_PREFETCH;
                } else {
                    features |= SDL_CPU_ALTIVEC_NOPREFETCH;
                }
            }
        }
    }
 
    for (i = 0; entries[i].func; ++i) {
        /* Check for matching pixel formats */
        if (src_format != entries[i].src_format) {
            continue;
        }
        if (dst_format != entries[i].dst_format) {
            continue;
        }
 
        /* Check flags */
        if ((flagcheck & entries[i].flags) != flagcheck) {
            continue;
        }
 
        /* Check CPU features */
        if ((entries[i].cpu & features) != entries[i].cpu) {
            continue;
        }
 
        /* We found the best one! */
        return entries[i].func;
    }
    return NULL;
}

References SDL_BlitFuncEntry::func, i, NULL, SDL_COPY_ADD, SDL_COPY_BLEND, SDL_COPY_COLORKEY, SDL_COPY_MOD, SDL_COPY_MODULATE_ALPHA, SDL_COPY_MODULATE_COLOR, SDL_COPY_MUL, SDL_COPY_NEAREST, SDL_CPU_3DNOW, SDL_CPU_ALTIVEC_NOPREFETCH, SDL_CPU_ALTIVEC_PREFETCH, SDL_CPU_ANY, SDL_CPU_MMX, SDL_CPU_SSE, SDL_CPU_SSE2, SDL_getenv, SDL_Has3DNow, SDL_HasAltiVec, SDL_HasMMX, SDL_HasSSE, SDL_HasSSE2, SDL_sscanf, and SDL_UseAltivecPrefetch().

Referenced by SDL_CalculateBlit().

SDL_SoftBlit()

static int SDL_SoftBlit ( SDL_Surface *  src, SDL_Rect *  srcrect, SDL_Surface *  dst, SDL_Rect *  dstrect  )

static

Definition at line 34 of file SDL_blit.c.

{
    int okay;
    int src_locked;
    int dst_locked;
 
    /* Everything is okay at the beginning...  */
    okay = 1;
 
    /* Lock the destination if it's in hardware */
    dst_locked = 0;
    if (SDL_MUSTLOCK(dst)) {
        if (SDL_LockSurface(dst) < 0) {
            okay = 0;
        } else {
            dst_locked = 1;
        }
    }
    /* Lock the source if it's in hardware */
    src_locked = 0;
    if (SDL_MUSTLOCK(src)) {
        if (SDL_LockSurface(src) < 0) {
            okay = 0;
        } else {
            src_locked = 1;
        }
    }
 
    /* Set up source and destination buffer pointers, and BLIT! */
    if (okay && !SDL_RectEmpty(srcrect)) {
        SDL_BlitFunc RunBlit;
        SDL_BlitInfo *info = &src->map->info;
 
        /* Set up the blit information */
        info->src = (Uint8 *) src->pixels +
            (Uint16) srcrect->y * src->pitch +
            (Uint16) srcrect->x * info->src_fmt->BytesPerPixel;
        info->src_w = srcrect->w;
        info->src_h = srcrect->h;
        info->src_pitch = src->pitch;
        info->src_skip =
            info->src_pitch - info->src_w * info->src_fmt->BytesPerPixel;
        info->dst =
            (Uint8 *) dst->pixels + (Uint16) dstrect->y * dst->pitch +
            (Uint16) dstrect->x * info->dst_fmt->BytesPerPixel;
        info->dst_w = dstrect->w;
        info->dst_h = dstrect->h;
        info->dst_pitch = dst->pitch;
        info->dst_skip =
            info->dst_pitch - info->dst_w * info->dst_fmt->BytesPerPixel;
        RunBlit = (SDL_BlitFunc) src->map->data;
 
        /* Run the actual software blit */
        RunBlit(info);
    }
 
    /* We need to unlock the surfaces if they're locked */
    if (dst_locked) {
        SDL_UnlockSurface(dst);
    }
    if (src_locked) {
        SDL_UnlockSurface(src);
    }
    /* Blit is done! */
    return (okay ? 0 : -1);
}

References SDL_PixelFormat::BytesPerPixel, SDL_BlitInfo::dst, SDL_BlitInfo::dst_fmt, SDL_BlitInfo::dst_h, SDL_BlitInfo::dst_pitch, SDL_BlitInfo::dst_skip, SDL_BlitInfo::dst_w, SDL_Rect::h, SDL_LockSurface, SDL_MUSTLOCK, SDL_RectEmpty(), SDL_UnlockSurface, SDL_BlitInfo::src, SDL_BlitInfo::src_fmt, SDL_BlitInfo::src_h, SDL_BlitInfo::src_pitch, SDL_BlitInfo::src_skip, SDL_BlitInfo::src_w, SDL_Rect::w, SDL_Rect::x, and SDL_Rect::y.

Referenced by SDL_CalculateBlit().

SDL_UseAltivecPrefetch()

static SDL_bool SDL_UseAltivecPrefetch ( )

static

Definition at line 122 of file SDL_blit.c.

{
    /* Just guess G4 */
    return SDL_TRUE;
}

References SDL_TRUE.

Referenced by SDL_ChooseBlitFunc().