Files
@ r19409:5ca3f7c4fb73
Branch filter:
Location: cpp/openttd-patchpack/source/src/blitter/base.cpp
r19409:5ca3f7c4fb73
3.2 KiB
text/x-c
(svn r24326) -Update from WebTranslator v3.0:
afrikaans - 11 changes by telanus
dutch - 7 changes by habell
german - 5 changes by Jogio
greek - 183 changes by kyrm
lithuanian - 4 changes by RunisLabs
polish - 50 changes by wojteks86
afrikaans - 11 changes by telanus
dutch - 7 changes by habell
german - 5 changes by Jogio
greek - 183 changes by kyrm
lithuanian - 4 changes by RunisLabs
polish - 50 changes by wojteks86
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 | /* $Id$ */
/*
* This file is part of OpenTTD.
* OpenTTD 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, version 2.
* OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file base.cpp Implementation of the base for all blitters. */
#include "../stdafx.h"
#include "base.hpp"
#include "../core/math_func.hpp"
void Blitter::DrawLine(void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8 colour, int width)
{
int dy;
int dx;
int stepx;
int stepy;
dy = (y2 - y) * 2;
if (dy < 0) {
dy = -dy;
stepy = -1;
} else {
stepy = 1;
}
dx = (x2 - x) * 2;
if (dx < 0) {
dx = -dx;
stepx = -1;
} else {
stepx = 1;
}
if (dx == 0 && dy == 0) {
/* The algorithm below cannot handle this special case; make it work at least for line width 1 */
if (x >= 0 && x < screen_width && y >= 0 && y < screen_height) this->SetPixel(video, x, y, colour);
return;
}
int frac_diff = width * max(dx, dy);
if (width > 1) {
/* compute frac_diff = width * sqrt(dx*dx + dy*dy)
* Start interval:
* max(dx, dy) <= sqrt(dx*dx + dy*dy) <= sqrt(2) * max(dx, dy) <= 3/2 * max(dx, dy) */
int frac_sq = width * width * (dx * dx + dy * dy);
int frac_max = 3 * frac_diff / 2;
while (frac_diff < frac_max) {
int frac_test = (frac_diff + frac_max) / 2;
if (frac_test * frac_test < frac_sq) {
frac_diff = frac_test + 1;
} else {
frac_max = frac_test - 1;
}
}
}
if (dx > dy) {
int y_low = y;
int y_high = y;
int frac_low = dy - frac_diff / 2;
int frac_high = dy + frac_diff / 2;
while (frac_low + dx / 2 < 0) {
frac_low += dx;
y_low -= stepy;
}
while (frac_high - dx / 2 >= 0) {
frac_high -= dx;
y_high += stepy;
}
x2 += stepx;
while (x != x2) {
if (x >= 0 && x < screen_width) {
for (int y = y_low; y != y_high; y += stepy) {
if (y >= 0 && y < screen_height) this->SetPixel(video, x, y, colour);
}
}
if (frac_low >= 0) {
y_low += stepy;
frac_low -= dx;
}
if (frac_high >= 0) {
y_high += stepy;
frac_high -= dx;
}
x += stepx;
frac_low += dy;
frac_high += dy;
}
} else {
int x_low = x;
int x_high = x;
int frac_low = dx - frac_diff / 2;
int frac_high = dx + frac_diff / 2;
while (frac_low + dy / 2 < 0) {
frac_low += dy;
x_low -= stepx;
}
while (frac_high - dy / 2 >= 0) {
frac_high -= dy;
x_high += stepx;
}
y2 += stepy;
while (y != y2) {
if (y >= 0 && y < screen_height) {
for (int x = x_low; x != x_high; x += stepx) {
if (x >= 0 && x < screen_width) this->SetPixel(video, x, y, colour);
}
}
if (frac_low >= 0) {
x_low += stepx;
frac_low -= dy;
}
if (frac_high >= 0) {
x_high += stepx;
frac_high -= dy;
}
y += stepy;
frac_low += dx;
frac_high += dx;
}
}
}
|