scummvm/saga/transitions.cpp

74 lines
1.8 KiB
C++

/* ScummVM - Scumm Interpreter
* Copyright (C) 2004-2005 The ScummVM project
*
* The ReInherit Engine is (C)2000-2003 by Daniel Balsom.
*
* 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.
*
* $Header$
*
*/
//Background transition routines
#include "saga/saga.h"
namespace Saga {
/**
* Dissolve one image with another.
* If flags if set to 1, do zero masking.
*/
int SagaEngine::transitionDissolve(byte *dst_img, int dst_w, int dst_h, int dst_p, const byte *src_img,
int src_w, int src_h, int src_p, int flags, int x, int y,
double percent) {
#define XOR_MASK 0xB400;
int pixelcount = dst_w * dst_h;
int seqlimit = (int)(65535 * percent);
int seq = 1;
int i, x1, y1;
Common::Rect clip(x, y, x+src_w, y+src_h);
byte color;
for (i = 0; i < seqlimit; i++) {
if (seq & 1) {
seq = (seq >> 1) ^ XOR_MASK;
} else {
seq = seq >> 1;
}
if (seq == 1) {
return 0;
}
if (seq >= pixelcount) {
continue;
} else {
x1 = seq % dst_w;
y1 = seq / dst_w;
if (clip.contains(x1, y1)) {
color = src_img[(x1-x)+src_w*(y1-y)];
if (flags == 0 || color)
dst_img[seq] = color;
}
}
}
return 1;
}
} // End of namespace Saga