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/* -*- C++ -*- */
/*
GAV - Gpl Arcade Volleyball
Copyright (C) 2002
GAV team (http://sourceforge.net/projects/gav/)
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* These functions are derived from SDL_buffer.
*/
#include <stdlib.h>
#include "ResizeSurface.h"
typedef struct tColorRGBA {
Uint8 r;
Uint8 g;
Uint8 b;
Uint8 a;
} tColorRGBA;
/*
* 32bit Zoomer with optional anti-aliasing by bilinear interpolation.
* Zoomes 32bit RGBA/ABGR 'src' surface to 'dst' surface.
* Forked from SDL_rotozoom.c, LGPL (c) A. Schiffler
*/
static int zoomSurfaceRGBA (SDL_Surface * src, SDL_Surface * dst)
{
int x, y, //current dst->x and dst->y
xscale, yscale, //src/dst proportions * 65536
*sx_offset, *sy_offset, //row/columnt increment tables
*csx_offset, *csy_offset, //pointers to current row/columnt increment element
csx, csy,
sgap, dgap;
tColorRGBA *sp, *csp, *dp;
// Variables setup
xscale = (int) (65536.0 * (double) src->w / (double) dst->w);
yscale = (int) (65536.0 * (double) src->h / (double) dst->h);
// Allocate memory for row increments
sx_offset = (int*)malloc((dst->w + 1) * sizeof(Uint32));
sy_offset = (int*)malloc((dst->h + 1) * sizeof(Uint32));
if (sx_offset == NULL || sy_offset == NULL) {
free(sx_offset);
free(sy_offset);
return -1;
}
// Precalculate row increments
csx = 0;
csx_offset = sx_offset;
for (x = 0; x <= dst->w; x++) {
*csx_offset = csx;
csx_offset++;
csx &= 0xffff;
csx += xscale;
}
csy = 0;
csy_offset = sy_offset;
for (y = 0; y <= dst->h; y++) {
*csy_offset = csy;
csy_offset++;
csy &= 0xffff;
csy += yscale;
}
// Pointer setup
sp = csp = (tColorRGBA *) src->pixels;
dp = (tColorRGBA *) dst->pixels;
sgap = src->pitch - src->w * 4;
dgap = dst->pitch - dst->w * 4;
// Switch between interpolating and non-interpolating code
// Non-Interpolating Zoom
csy_offset = sy_offset;
for (y = 0; y < dst->h; y++) {
sp = csp;
csx_offset = sx_offset;
for (x = 0; x < dst->w; x++) {
// Draw
*dp = *sp;
// Advance source pointers
csx_offset++;
sp += (*csx_offset >> 16);
// Advance destination pointer
dp++;
}
// Advance source pointer
csy_offset++;
csp = (tColorRGBA *) ((Uint8 *) csp + (*csy_offset >> 16) * src->pitch);
// Advance destination pointers
dp = (tColorRGBA *) ((Uint8 *) dp + dgap);
}
// Remove temp arrays
free(sx_offset);
free(sy_offset);
return 0;
}
SDL_Surface * resizeSurface (SDL_Surface * buf, int width, int height) {
SDL_PixelFormat * format = buf->format;
int dst_w, dst_h;
Uint32 Rmask,Gmask,Bmask,Amask;
SDL_Surface * dest;
SDL_Surface * tmp;
bool toFree = false;
if (format->BitsPerPixel == 32) {
Rmask = format->Rmask;
Gmask = format->Gmask;
Bmask = format->Bmask;
Amask = format->Amask;
} else {
Rmask = 0x000000ff;
Gmask = 0x0000ff00;
Bmask = 0x00ff0000;
Amask = 0xff000000;
}
if (format->BitsPerPixel != 32 ||
format->Rmask != Rmask ||
format->Gmask != Gmask ||
format->Bmask != Bmask) {
// New source surface is 32bit with defined RGBA ordering.
// Note that Amask has been ignored in test
tmp = SDL_CreateRGBSurface (SDL_SWSURFACE, buf->w, buf->h, 32,
Rmask, Gmask, Bmask, Amask);
SDL_BlitSurface (buf, NULL, tmp, NULL);
toFree = true;
} else
tmp = buf;
dst_w = width;
dst_h = height;
// Alloc space to completely contain the zoomed surface
// Target surface is 32bit with source RGBA/ABGR ordering
// (note that buf->zoom is already NULL)
dest = SDL_CreateRGBSurface (SDL_SWSURFACE, width, height, 32,
Rmask, Gmask, Bmask, Amask);
SDL_LockSurface(tmp);
SDL_LockSurface(dest);
zoomSurfaceRGBA(tmp, dest);
// Turn on source-alpha support
SDL_SetAlpha(dest, SDL_SRCALPHA, 255);
SDL_UnlockSurface(tmp);
SDL_UnlockSurface(dest);
if (toFree) SDL_FreeSurface(tmp);
// Return destination surface
return dest;
}
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