view src/video/SDL_blit.c @ 3502:98a819296cdc

Whenever a window becomes fullscreen, shown, unminimized, and has input focus it will change the display to the corresponding fullscreen video mode. If it loses any of those properties the desktop mode will be restored.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 01 Dec 2009 08:56:12 +0000
parents 99210400e8b9
children f7b03b6838cb
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    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
    Lesser General Public License for more details.

    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

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.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"

/* The general purpose software blit routine */
static int
SDL_SoftBlit(SDL_Surface * src, SDL_Rect * srcrect,
             SDL_Surface * dst, SDL_Rect * dstrect)
{
    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 && srcrect->w && srcrect->h) {
        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);
}

#ifdef __MACOSX__
#include <sys/sysctl.h>

static SDL_bool
SDL_UseAltivecPrefetch()
{
    const char key[] = "hw.l3cachesize";
    u_int64_t result = 0;
    size_t typeSize = sizeof(result);

    if (sysctlbyname(key, &result, &typeSize, NULL, 0) == 0 && result > 0) {
        return SDL_TRUE;
    } else {
        return SDL_FALSE;
    }
}
#else
static SDL_bool
SDL_UseAltivecPrefetch()
{
    /* Just guess G4 */
    return SDL_TRUE;
}
#endif /* __MACOSX__ */

static SDL_BlitFunc
SDL_ChooseBlitFunc(Uint32 src_format, Uint32 dst_format, int flags,
                   SDL_BlitFuncEntry * entries)
{
    int i, flagcheck;
    static Uint32 features = 0xffffffff;

    /* Get the available CPU features */
    if (features == 0xffffffff) {
        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 modulation flags */
        flagcheck =
            (flags & (SDL_COPY_MODULATE_COLOR | SDL_COPY_MODULATE_ALPHA));
        if ((flagcheck & entries[i].flags) != flagcheck) {
            continue;
        }

        /* Check blend flags */
        flagcheck =
            (flags &
             (SDL_COPY_MASK | SDL_COPY_BLEND | SDL_COPY_ADD | SDL_COPY_MOD));
        if ((flagcheck & entries[i].flags) != flagcheck) {
            continue;
        }

        /* Check colorkey flag */
        flagcheck = (flags & SDL_COPY_COLORKEY);
        if ((flagcheck & entries[i].flags) != flagcheck) {
            continue;
        }

        /* Check scaling flags */
        flagcheck = (flags & SDL_COPY_NEAREST);
        if ((flagcheck & entries[i].flags) != flagcheck) {
            continue;
        }

        /* Check CPU features */
        flagcheck = entries[i].cpu;
        if ((flagcheck & features) != flagcheck) {
            continue;
        }

        /* We found the best one! */
        return entries[i].func;
    }
    return NULL;
}

/* Figure out which of many blit routines to set up on a surface */
int
SDL_CalculateBlit(SDL_Surface * surface)
{
    SDL_BlitFunc blit = NULL;
    SDL_BlitMap *map = surface->map;
    SDL_Surface *dst = map->dst;

    /* Clean everything out to start */
    if ((surface->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
        SDL_UnRLESurface(surface, 1);
    }
    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;

    /* See if we can do RLE acceleration */
    if (map->info.flags & SDL_COPY_RLE_DESIRED) {
        if (SDL_RLESurface(surface) == 0) {
            return 0;
        }
    }

    /* Choose a standard blit function */
    if (map->identity && !(map->info.flags & ~SDL_COPY_RLE_DESIRED)) {
        /* Handle overlapping blits on the same surface */
        if (surface == dst) {
            blit = SDL_BlitCopyOverlap;
        } else {
            blit = SDL_BlitCopy;
        }
    } else if (surface->format->BitsPerPixel < 8) {
        blit = SDL_CalculateBlit0(surface);
    } else if (surface->format->BytesPerPixel == 1) {
        blit = SDL_CalculateBlit1(surface);
    } else if (map->info.flags & SDL_COPY_BLEND) {
        blit = SDL_CalculateBlitA(surface);
    } else {
        blit = SDL_CalculateBlitN(surface);
    }
    if (blit == NULL) {
        Uint32 src_format =
            SDL_MasksToPixelFormatEnum(surface->format->BitsPerPixel,
                                       surface->format->Rmask,
                                       surface->format->Gmask,
                                       surface->format->Bmask,
                                       surface->format->Amask);
        Uint32 dst_format =
            SDL_MasksToPixelFormatEnum(dst->format->BitsPerPixel,
                                       dst->format->Rmask,
                                       dst->format->Gmask,
                                       dst->format->Bmask,
                                       dst->format->Amask);

        blit =
            SDL_ChooseBlitFunc(src_format, dst_format, map->info.flags,
                               SDL_GeneratedBlitFuncTable);
    }
#ifndef TEST_SLOW_BLIT
    if (blit == NULL)
#endif
    {
        if (surface->format->BytesPerPixel > 1
            && dst->format->BytesPerPixel > 1) {
            blit = SDL_Blit_Slow;
        }
    }
    map->data = blit;

    /* Make sure we have a blit function */
    if (blit == NULL) {
        SDL_InvalidateMap(map);
        SDL_SetError("Blit combination not supported");
        return (-1);
    }

    return (0);
}

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