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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "common/util.h"
namespace Graphics {
void drawLine(int x0, int y0, int x1, int y1, int color, void (*plotProc)(int, int, int, void *), void *data) {
// Bresenham's line algorithm, as described by Wikipedia
const bool steep = ABS(y1 - y0) > ABS(x1 - x0);
if (steep) {
SWAP(x0, y0);
SWAP(x1, y1);
}
const int delta_x = ABS(x1 - x0);
const int delta_y = ABS(y1 - y0);
const int delta_err = delta_y;
int x = x0;
int y = y0;
int err = 0;
const int x_step = (x0 < x1) ? 1 : -1;
const int y_step = (y0 < y1) ? 1 : -1;
if (steep)
(*plotProc)(y, x, color, data);
else
(*plotProc)(x, y, color, data);
while (x != x1) {
x += x_step;
err += delta_err;
if (2 * err > delta_x) {
y += y_step;
err -= delta_x;
}
if (steep)
(*plotProc)(y, x, color, data);
else
(*plotProc)(x, y, color, data);
}
}
void drawThickLine(int x0, int y0, int x1, int y1, int penX, int penY, int color, void (*plotProc)(int, int, int, void *), void *data) {
assert(penX > 0 && penY > 0);
// Shortcut
if (penX == 1 && penY == 1) {
drawLine(x0, y0, x1, y1, color, plotProc, data);
return;
}
// TODO: Optimize this. It currently is a very naive way of handling
// thick lines since quite often it will be drawing to the same pixel
// multiple times.
for (int x = 0; x < penX; x++)
for (int y = 0; y < penY; y++)
drawLine(x0 + x, y0 + y, x1 + x, y1 + y, color, plotProc, data);
}
} // End of namespace Graphics
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