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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);
}
}
// FIXME: This is a limited version of thick line drawing
// it draws striped lines at some angles. Better algorithm could
// be found here:
//
// http://homepages.enterprise.net/murphy/thickline/index.html
//
// Feel free to replace it with better implementation
void drawThickLine(int x0, int y0, int x1, int y1, int thickness, int color, void (*plotProc)(int, int, int, void *), void *data) {
const bool steep = ABS(y1 - y0) > ABS(x1 - x0);
if (steep) {
SWAP(x0, y0);
SWAP(x1, y1);
}
float dx = x1 - x0;
float dy = y1 - y0;
float d = (float)sqrt(dx * dx + dy * dy);
if (!d)
return;
int thickX = (int)((float)thickness * dy / d / 2);
int thickY = (int)((float)thickness * dx / d / 2);
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)
drawLine(y - thickY, x + thickX, y + thickY, x - thickX, color, plotProc, data);
else
drawLine(x - thickX, y + thickY, x + thickX, y - thickY, color, plotProc, data);
while (x != x1) {
x += x_step;
err += delta_err;
if (2 * err > delta_x) {
y += y_step;
err -= delta_x;
}
if (steep)
drawLine(y - thickY, x + thickX, y + thickY, x - thickX, color, plotProc, data);
else
drawLine(x - thickX, y + thickY, x + thickX, y - thickY, color, plotProc, data);
}
}
} // End of namespace Graphics
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