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@ r19293:3f2cb83a321f
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Location: cpp/openttd-patchpack/source/src/blitter/base.cpp
r19293:3f2cb83a321f
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(svn r24196) -Update from WebTranslator v3.0:
afrikaans - 33 changes by telanus
belarusian - 6 changes by KorneySan, Wowanxm
croatian - 4 changes by VoyagerOne
czech - 4 changes by Paragulis
dutch - 8 changes by habell
english_AU - 19 changes by tomas4g
english_US - 4 changes by Rubidium
finnish - 4 changes by jpx_
french - 4 changes by OliTTD
german - 4 changes by NG
italian - 4 changes by lorenzodv
lithuanian - 22 changes by Stabilitronas
polish - 4 changes by wojteks86
russian - 6 changes by KorneySan
afrikaans - 33 changes by telanus
belarusian - 6 changes by KorneySan, Wowanxm
croatian - 4 changes by VoyagerOne
czech - 4 changes by Paragulis
dutch - 8 changes by habell
english_AU - 19 changes by tomas4g
english_US - 4 changes by Rubidium
finnish - 4 changes by jpx_
french - 4 changes by OliTTD
german - 4 changes by NG
italian - 4 changes by lorenzodv
lithuanian - 22 changes by Stabilitronas
polish - 4 changes by wojteks86
russian - 6 changes by KorneySan
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;
}
}
}
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