/usr/share/gnu-smalltalk/examples/CairoDemo.st is in gnu-smalltalk-common 3.2.5-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 | "======================================================================
|
| Blitting example using Cairo and SDL
|
|
======================================================================"
"======================================================================
|
| Copyright 2008 Free Software Foundation, Inc.
| Written by Paolo Bonzini.
|
| This file is part of GNU Smalltalk.
|
| GNU Smalltalk 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, or (at your option) any later version.
|
| GNU Smalltalk 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
| GNU Smalltalk; see the file COPYING. If not, write to the Free Software
| Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
|
======================================================================"
PackageLoader fileInPackage: #CairoSDL.
PackageLoader fileInPackage: #'LibSDL_GL'.
SDL.SdlEventHandler subclass: CairoDemo [
| context surface |
<import: SDL>
<import: Cairo>
context [ ^context ]
samples [
^#(#arc #arcNegative #clip #curveRectangle #curveTo #gradient
#fillStroke #fillRule #png)
]
arcNegative [
| ang1 ang2 |
ang1 := 45 degreesToRadians.
ang2 := 180 degreesToRadians.
context
lineWidth: 10;
stroke: [ context arcNegative: 128@128 radius: 100 from: ang1 to: ang2 ];
paint: [
context
lineWidth: 6;
sourceRed: 1 green: 0.2 blue: 0.2 alpha: 1.0;
fill: [ context arc: 128@128 radius: 10 from: 0 to: Float pi * 2 ];
stroke: [
context
arc: 128@128 radius: 100 from: ang1 to: ang1;
lineTo: 128@128;
arc: 128@128 radius: 100 from: ang2 to: ang2;
lineTo: 128@128 ]]
withAlpha: 0.64
]
arc [
| ang1 ang2 |
ang1 := 45 degreesToRadians.
ang2 := 180 degreesToRadians.
context
lineWidth: 10;
stroke: [ context arc: 128@128 radius: 100 from: ang1 to: ang2 ];
sourceRed: 1 green: 0.2 blue: 0.2 alpha: 0.6;
lineWidth: 6;
fill: [ context arc: 128@128 radius: 10 from: 0 to: Float pi * 2 ];
stroke: [
context
arc: 128@128 radius: 100 from: ang1 to: ang1;
lineTo: 128@128;
arc: 128@128 radius: 100 from: ang2 to: ang2;
lineTo: 128@128 ]
]
clip [
context
clip: [ context arc: 128@128 radius: 77 from: 0 to: Float pi * 2 ];
fill: [ context rectangle: (0@0 extent: 256@256) ];
lineWidth: 10;
stroke: [
context
moveTo: 0@0;
lineTo: 256@256;
moveTo: 256@0;
lineTo: 0@256 ]
with: Color green
]
curveRectangle [
| x0 x1 y0 y1 mx0 mx1 my0 my1 |
x0 := y0 := 25.6.
x1 := y1 := 256 - x0.
mx0 := x0 + 52.4.
mx1 := x1 - 52.4.
my0 := y0 + 52.4.
my1 := y1 - 52.4.
context
withClosedPath: [
context
moveTo: x0@my0;
curveTo: mx0@y0 via: x0@y0 via: mx0@y0;
lineTo: mx1@y0;
curveTo: x1@my0 via: x1@y0 via: x1@my0;
lineTo: x1@my1;
curveTo: mx1@y1 via: x1@y1 via: mx1@y1;
lineTo: mx0@y1;
curveTo: x0@my1 via: x0@y1 via: x0@my1 ]
do: [
context
fillWith: (Color r: 0.5 g: 0.5 b: 1);
lineWidth: 10;
strokeWith: (Color r: 0.5 g: 0 b: 0 a: 0.5) ]
]
curveTo [
| p0 p1 p2 p3 |
p0 := 25.6@128.
p1 := 102.4@230.4.
p2 := 153.6@25.6.
p3 := 230.4@128.
context
lineWidth: 10;
stroke: [ context moveTo: p0; curveTo: p3 via: p1 via: p2 ];
lineWidth: 6;
stroke: [ context moveTo: p0; lineTo: p1; moveTo: p2; lineTo: p3 ]
with: (Color r: 1 g: 0.2 b: 0.2 a: 0.6)
]
fillStroke [
context withPath: [
context
addClosedSubPath: [
context
moveTo: 128@25.6;
lineTo: 230.4@230.4;
relLineTo: -102.4@0;
curveVia: 51.2@230.4 via: 51.2@128 to: 128@128 ];
addClosedSubPath: [
context
moveTo: 64.0@25.6;
relLineTo: 51.2@51.2;
relLineTo: -51.2@51.2;
relLineTo: -51.2 @ -51.2 ]]
do: [
context
lineWidth: 10;
fillWith: Color blue;
strokeWith: Color black ]
]
png [
| png scale translate surf |
(File exists: 'demo.png') ifFalse: [ ^self ].
png := CairoPngSurface on: 'demo.png'.
scale := 256.0 / (png extent x max: png extent y).
translate := 128@128 - (png extent / 2 * scale).
context
translateBy: translate;
scaleBy: scale;
paintWith: (surf := SurfacePattern on: png).
surf release.
png release
]
fillRule [
| path |
path := [
context rectangle: (12@12 extent: 232@70).
context addSubPath: [
context arc: 64@64 radius: 40 from: 0 to: 2 * Float pi ].
context addSubPath: [
context arcNegative: 192@64 radius: 40 from: 0 to: -2 * Float pi ]].
context lineWidth: 6.
context
withPath: path
do: [
context
fillRule: #evenOdd;
fillWith: Color green * 0.7;
strokeWith: Color black ].
context
translateBy: 0@128;
withPath: path
do: [
context
fillRule: #winding;
fillWith: Color blue * 0.9;
strokeWith: Color black ].
]
gradient [
| linear radial |
linear := LinearGradient from: 0@0 to: 0@256.
linear addStopAt: 0 color: Color white.
linear addStopAt: 1 color: Color black.
radial := RadialGradient from: 115.2@102.4 radius: 25.6
to: 102.4@102.4 radius: 128.
radial addStopAt: 0 color: Color white.
radial addStopAt: 1 color: Color black.
context
fill: [ context rectangle: (0@0 extent: 256@256) ]
with: linear;
fill: [ context arc: 128@128 radius: 77 from: 0 to: Float pi * 2]
with: radial.
]
cols [
^self samples size sqrt ceiling.
]
rows [
^(self samples size / self cols) ceiling.
]
displaySize [
| defSize cols rows |
defSize := SdlDisplay defaultSize.
cols := self cols.
rows := self rows.
^defSize x * rows / cols > defSize y
ifTrue: [ ^(cols@rows) * (defSize y / rows) ]
ifFalse: [ ^(cols@rows) * (defSize x / cols) ]
]
clippingRectangle: index [
| cols rows col row size |
cols := self cols.
rows := self rows.
col := (index - 1) \\ cols.
row := (index - 1) // cols.
size := SdlDisplay current extent / (cols @ rows).
^size * (col @ row) extent: size
]
run [
SdlDisplay defaultFormat
resizable: true;
extent: self displaySize.
"SdlDisplay current: SdlGLDisplay new."
SdlDisplay current eventSource handler: self; startEventLoop.
Processor activeProcess terminateOnQuit.
surface := CairoSdlSurface on: SdlDisplay current.
self draw.
(CairoPngSurface on: 'demo.png' with: surface) save.
]
handleResize: size [
super handleResize: size.
self draw
]
draw [
surface withContextDo: [ :ctx |
context := ctx.
context paintWith: Color white.
self samples keysAndValuesDo: [ :index :sel |
self draw: sel inside: (self clippingRectangle: index) ] ].
]
draw: sel inside: rect [
| size |
size := rect width min: rect height.
context saveWhile: [
context
resetClip;
withPath: [ context rectangle: rect ] do: [ context clip ];
translateBy: rect origin + ((rect extent - size) / 2);
scaleBy: size / 256.
self perform: sel ]
]
]
Eval [
s := Semaphore new.
[CairoDemo new run. s signal] fork.
s wait
]
|