surface.c

libminigui-1.3.0.tar.gz。 miniGUI的库函数源代码！

/*
**  $Id: surface.c,v 1.21 2003/11/22 03:53:11 weiym Exp $
**  
**  Port to MiniGUI by Wei Yongming (2001/10/03).
**  Copyright (C) 2001 ~ 2002 Wei Yongming.
**  Copyright (C) 2003 Feynman Software.
**
**  SDL - Simple DirectMedia Layer
**  Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga
*/

/*
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** This program 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 General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "common.h"
#include "newgal.h"
#include "sysvideo.h"
#include "blit.h"
#include "RLEaccel_c.h"
#include "pixels_c.h"
#include "memops.h"
#include "leaks.h"

/* Public routines */
/*
 * Create an empty RGB surface of the appropriate depth
 */
GAL_Surface * GAL_CreateRGBSurface (Uint32 flags,
            int width, int height, int depth,
            Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
{
    GAL_VideoDevice *video = current_video;
    GAL_VideoDevice *this  = current_video;
    GAL_Surface *screen;
    GAL_Surface *surface;

    /* Check to see if we desire the surface in video memory */
    if ( video ) {
        screen = GAL_PublicSurface;
    } else {
        screen = NULL;
    }
    if ( screen && ((screen->flags&GAL_HWSURFACE) == GAL_HWSURFACE) ) {
        if ( (flags&(GAL_SRCCOLORKEY|GAL_SRCALPHA)) != 0 ) {
            flags |= GAL_HWSURFACE;
        }
        if ( (flags & GAL_SRCCOLORKEY) == GAL_SRCCOLORKEY ) {
            if ( ! current_video->info.blit_hw_CC ) {
                flags &= ~GAL_HWSURFACE;
            }
        }
        if ( (flags & GAL_SRCALPHA) == GAL_SRCALPHA ) {
            if ( ! current_video->info.blit_hw_A ) {
                flags &= ~GAL_HWSURFACE;
            }
        }
    } else {
        flags &= ~GAL_HWSURFACE;
    }

    /* Allocate the surface */
    surface = (GAL_Surface *)malloc(sizeof(*surface));
    if ( surface == NULL ) {
        GAL_OutOfMemory();
        return(NULL);
    }
    surface->flags = GAL_SWSURFACE;
    if ( (flags & GAL_HWSURFACE) == GAL_HWSURFACE ) {
        depth = screen->format->BitsPerPixel;
        Rmask = screen->format->Rmask;
        Gmask = screen->format->Gmask;
        Bmask = screen->format->Bmask;
        Amask = screen->format->Amask;
    }
    surface->format = GAL_AllocFormat(depth, Rmask, Gmask, Bmask, Amask);
    if ( surface->format == NULL ) {
        free(surface);
        return(NULL);
    }
    if ( Amask ) {
        surface->flags |= GAL_SRCALPHA;
    }
    surface->w = width;
    surface->h = height;
    surface->pitch = GAL_CalculatePitch(surface);
    surface->pixels = NULL;
    surface->offset = 0;
    surface->hwdata = NULL;
    surface->locked = 0;
    surface->map = NULL;
    surface->format_version = 0;
    GAL_SetClipRect(surface, NULL);

    /* Get the pixels */
    if ( ((flags&GAL_HWSURFACE) == GAL_SWSURFACE) || 
                (video->AllocHWSurface(this, surface) < 0) ) {
        if ( surface->w && surface->h ) {
            surface->pixels = malloc(surface->h*surface->pitch);
            if ( surface->pixels == NULL ) {
                GAL_FreeSurface(surface);
                GAL_OutOfMemory();
                return(NULL);
            }
            /* This is important for bitmaps */
            memset(surface->pixels, 0, surface->h*surface->pitch);
        }
    }

    /* Allocate an empty mapping */
    surface->map = GAL_AllocBlitMap();
    if ( surface->map == NULL ) {
        GAL_FreeSurface(surface);
        return(NULL);
    }

    /* The surface is ready to go */
    surface->refcount = 1;
#ifdef CHECK_LEAKS
    ++surfaces_allocated;
#endif
    return(surface);
}
/*
 * Create an RGB surface from an existing memory buffer
 */
GAL_Surface * GAL_CreateRGBSurfaceFrom (void *pixels,
            int width, int height, int depth, int pitch,
            Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
{
    GAL_Surface *surface;

    surface = GAL_CreateRGBSurface(GAL_SWSURFACE, 0, 0, depth,
                                   Rmask, Gmask, Bmask, Amask);
    if ( surface != NULL ) {
        surface->flags |= GAL_PREALLOC;
        surface->pixels = pixels;
        surface->w = width;
        surface->h = height;
        surface->pitch = pitch;
        GAL_SetClipRect(surface, NULL);
    }
    return(surface);
}
/*
 * Set the color key in a blittable surface
 */
int GAL_SetColorKey (GAL_Surface *surface, Uint32 flag, Uint32 key)
{
    /* Sanity check the flag as it gets passed in */
    if ( flag & GAL_SRCCOLORKEY ) {
        if ( flag & (GAL_RLEACCEL|GAL_RLEACCELOK) ) {
            flag = (GAL_SRCCOLORKEY | GAL_RLEACCELOK);
        } else {
            flag = GAL_SRCCOLORKEY;
        }
    } else {
        flag = 0;
    }

    /* Optimize away operations that don't change anything */
    if ( (flag == (surface->flags & (GAL_SRCCOLORKEY|GAL_RLEACCELOK))) &&
         (key == surface->format->colorkey) ) {
        return(0);
    }

    /* UnRLE surfaces before we change the colorkey */
    if ( surface->flags & GAL_RLEACCEL ) {
            GAL_UnRLESurface(surface, 1);
    }

    if ( flag ) {
        GAL_VideoDevice *video = current_video;
        GAL_VideoDevice *this  = current_video;

        surface->flags |= GAL_SRCCOLORKEY;
        surface->format->colorkey = key;
        if ( (surface->flags & GAL_HWACCEL) == GAL_HWACCEL ) {
            if ( (video->SetHWColorKey == NULL) ||
                 (video->SetHWColorKey(this, surface, key) < 0) ) {
                surface->flags &= ~GAL_HWACCEL;
            }
        }
        if ( flag & GAL_RLEACCELOK ) {
            surface->flags |= GAL_RLEACCELOK;
        } else {
            surface->flags &= ~GAL_RLEACCELOK;
        }
    } else {
        surface->flags &= ~(GAL_SRCCOLORKEY|GAL_RLEACCELOK);
        surface->format->colorkey = 0;
    }
    GAL_InvalidateMap(surface->map);
    return(0);
}
int GAL_SetAlpha (GAL_Surface *surface, Uint32 flag, Uint8 value)
{
    Uint32 oldflags = surface->flags;
    Uint32 oldalpha = surface->format->alpha;

    /* Sanity check the flag as it gets passed in */
    if ( flag & GAL_SRCALPHA ) {
        if ( flag & (GAL_RLEACCEL|GAL_RLEACCELOK) ) {
            flag = (GAL_SRCALPHA | GAL_RLEACCELOK);
        } else {
            flag = GAL_SRCALPHA;
        }
    } else {
        flag = 0;
    }

    /* Optimize away operations that don't change anything */
    if ( (flag == (surface->flags & (GAL_SRCALPHA|GAL_RLEACCELOK))) &&
         (!flag || value == oldalpha) ) {
        return(0);
    }

    if(!(flag & GAL_RLEACCELOK) && (surface->flags & GAL_RLEACCEL))
        GAL_UnRLESurface(surface, 1);

    if ( flag ) {
        GAL_VideoDevice *video = current_video;
        GAL_VideoDevice *this  = current_video;

        surface->flags |= GAL_SRCALPHA;
        surface->format->alpha = value;
        if ( (surface->flags & GAL_HWACCEL) == GAL_HWACCEL ) {
            if ( (video->SetHWAlpha == NULL) ||
                 (video->SetHWAlpha(this, surface, value) < 0) ) {
                surface->flags &= ~GAL_HWACCEL;
            }
        }
        if ( flag & GAL_RLEACCELOK ) {
                surface->flags |= GAL_RLEACCELOK;
        } else {
                surface->flags &= ~GAL_RLEACCELOK;
        }
    } else {
        surface->flags &= ~GAL_SRCALPHA;
        surface->format->alpha = GAL_ALPHA_OPAQUE;
    }
    /*
     * The representation for software surfaces is independent of
     * per-surface alpha, so no need to invalidate the blit mapping
     * if just the alpha value was changed. (If either is 255, we still
     * need to invalidate.)
     */
    if((surface->flags & GAL_HWACCEL) == GAL_HWACCEL
       || oldflags != surface->flags
       || (((oldalpha + 1) ^ (value + 1)) & 0x100))
        GAL_InvalidateMap(surface->map);
    return(0);
}

/*
 * A function to calculate the intersection of two rectangles:
 * return true if the rectangles intersect, false otherwise
 */
static __inline__
GAL_bool GAL_IntersectRect(const GAL_Rect *A, const GAL_Rect *B, GAL_Rect *intersection)
{
    int Amin, Amax, Bmin, Bmax;

    /* Horizontal intersection */
    Amin = A->x;
    Amax = Amin + A->w;
    Bmin = B->x;
    Bmax = Bmin + B->w;
    if(Bmin > Amin)
            Amin = Bmin;
    intersection->x = Amin;
    if(Bmax < Amax)
            Amax = Bmax;
    intersection->w = Amax - Amin > 0 ? Amax - Amin : 0;

    /* Vertical intersection */
    Amin = A->y;
    Amax = Amin + A->h;
    Bmin = B->y;
    Bmax = Bmin + B->h;
    if(Bmin > Amin)
            Amin = Bmin;
    intersection->y = Amin;
    if(Bmax < Amax)
            Amax = Bmax;
    intersection->h = Amax - Amin > 0 ? Amax - Amin : 0;

    return (intersection->w && intersection->h);
}
/*
 * Set the clipping rectangle for a blittable surface
 */
GAL_bool GAL_SetClipRect(GAL_Surface *surface, GAL_Rect *rect)
{
    GAL_Rect full_rect;

    /* Don't do anything if there's no surface to act on */
    if ( ! surface ) {
        return GAL_FALSE;
    }

    /* Set up the full surface rectangle */
    full_rect.x = 0;
    full_rect.y = 0;
    full_rect.w = surface->w;
    full_rect.h = surface->h;

    /* Set the clipping rectangle */
    if ( ! rect ) {
        surface->clip_rect = full_rect;
        return 1;
    }
    return GAL_IntersectRect(rect, &full_rect, &surface->clip_rect);
}
void GAL_GetClipRect(GAL_Surface *surface, GAL_Rect *rect)
{
    if ( surface && rect ) {
        *rect = surface->clip_rect;
    }
}
/* 
 * Set up a blit between two surfaces -- split into three parts:
 * The upper part, GAL_UpperBlit(), performs clipping and rectangle 
 * verification.  The lower part is a pointer to a low level
 * accelerated blitting function.
 *
 * These parts are separated out and each used internally by this 
 * library in the optimimum places.  They are exported so that if
 * you know exactly what you are doing, you can optimize your code
 * by calling the one(s) you need.
 */
int GAL_LowerBlit (GAL_Surface *src, GAL_Rect *srcrect,
                GAL_Surface *dst, GAL_Rect *dstrect)
{
    GAL_blit do_blit;

    /* Check to make sure the blit mapping is valid */
    if ( (src->map->dst != dst) ||
             (src->map->dst->format_version != src->map->format_version) ) {
        if ( GAL_MapSurface(src, dst) < 0 ) {
            return(-1);
        }
    }

    /* Figure out which blitter to use */
    if ( (src->flags & GAL_HWACCEL) == GAL_HWACCEL ) {
        do_blit = src->map->hw_blit;
    } else {
        do_blit = src->map->sw_blit;
    }
    return(do_blit(src, srcrect, dst, dstrect));
}


int GAL_UpperBlit (GAL_Surface *src, GAL_Rect *srcrect,
           GAL_Surface *dst, GAL_Rect *dstrect)
{
    GAL_Rect fulldst;
    int srcx, srcy, w, h;

    /* Make sure the surfaces aren't locked */
    if ( ! src || ! dst ) {
        GAL_SetError("GAL_UpperBlit: passed a NULL surface");
        return(-1);
    }
    if ( src->locked || dst->locked ) {
        GAL_SetError("Surfaces must not be locked during blit");
        return(-1);
    }

    /* If the destination rectangle is NULL, use the entire dest surface */
    if ( dstrect == NULL ) {
        fulldst.x = fulldst.y = 0;
        dstrect = &fulldst;
    }

    /* clip the source rectangle to the source surface */
    if(srcrect) {
        int maxw, maxh;
    
        srcx = srcrect->x;
        w = srcrect->w;
        if(srcx < 0) {
            w += srcx;
            dstrect->x -= srcx;
            srcx = 0;
        }
        maxw = src->w - srcx;
        if(maxw < w)
            w = maxw;

        srcy = srcrect->y;
        h = srcrect->h;
        if(srcy < 0) {
                h += srcy;
            dstrect->y -= srcy;
            srcy = 0;
        }
        maxh = src->h - srcy;
        if(maxh < h)
            h = maxh;
        
    } else {
        srcx = srcy = 0;
        w = src->w;
        h = src->h;
    }

    /* clip the destination rectangle against the clip rectangle */
    {
        GAL_Rect *clip = &dst->clip_rect;
        int dx, dy;

        dx = clip->x - dstrect->x;
        if(dx > 0) {
            w -= dx;
            dstrect->x += dx;
            srcx += dx;
        }
        dx = dstrect->x + w - clip->x - clip->w;
        if(dx > 0)
            w -= dx;

        dy = clip->y - dstrect->y;
        if(dy > 0) {
            h -= dy;
            dstrect->y += dy;
            srcy += dy;
        }
        dy = dstrect->y + h - clip->y - clip->h;
        if(dy > 0)
            h -= dy;
    }

    if(w > 0 && h > 0) {
        GAL_Rect sr;
        sr.x = srcx;