mirror of
https://github.com/libretro/scummvm.git
synced 2024-11-30 21:00:39 +00:00
82 lines
2.3 KiB
C++
82 lines
2.3 KiB
C++
/* 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
|