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*.swp | ||
.DS_Store |
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# Chipmunk for Javascript! | ||
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This is a port of the [Chipmunk Physics](http://chipmunk-physics.net/) library to Javascript! | ||
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Its not complete. | ||
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## Caveats | ||
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- Some features are not implemented. Namely: | ||
- The spatial hash - based space | ||
- Joints. (The infrastructure is there, but the joints themselves haven't been ported yet) | ||
- It is much slower than the C version (duh, its in javascript). Specifically, physics simulations using chipmunk-js run between 3-7 times slower than the C equivalent. I expect to make big improvements to that over the next few months. | ||
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# Usage | ||
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The API for Chipmunk-js is almost identical to chipmunk-physics. Except: | ||
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- The `cp` prefix has gone | ||
- Most functions are wrapped by their containing objects | ||
- Some functions took an array-and-length. Arrays are now all simply javascript arrays, and the length argument has been removed. Eg: | ||
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```c | ||
cpMomentForPoly(mass, numVerts, *verts, offset); | ||
``` | ||
is now simply: | ||
```javascript | ||
momentForPoly(mass, verts, offset); | ||
``` | ||
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## Example | ||
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This code creates a new space, sets 10 physics iterations per update (these increase simulation stability). Then it adds a bunch of line segments to the space. | ||
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In C, this code looked like: | ||
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```C | ||
space = cpSpaceNew(); | ||
space->iterations = 10; | ||
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cpVect offset = cpv(-320, -240); | ||
for(int i=0; i<(bouncy_terrain_count - 1); i++){ | ||
cpVect a = bouncy_terrain_verts[i], b = bouncy_terrain_verts[i+1]; | ||
cpShape *shape = cpSpaceAddShape(space, cpSegmentShapeNew(space->staticBody, cpvadd(a, offset), cpvadd(b, offset), 0.0f)); | ||
cpShapeSetElasticity(shape, 1.0f); | ||
} | ||
``` | ||
In javascript, the equivalent code is: | ||
```javascript | ||
space = new cp.Space(); | ||
space.iterations = 10; | ||
var offset = new cp.Vect(-320, -240); | ||
for(var i=0; i<(bouncy_terrain_verts.length - 1); i++){ | ||
var a = bouncy_terrain_verts[i], b = bouncy_terrain_verts[i+1]; | ||
var shape = space.addShape(new cp.SegmentShape(space.staticBody, cp.vadd(a, offset), cp.vadd(b, offset), 0)); | ||
shape.setElasticity(1); | ||
} | ||
``` | ||
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# License | ||
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Like Chipmunk, chipmunk-js is MIT licensed. | ||
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``` | ||
Copyright (c) 2007 Scott Lembcke and Joseph Gentle | ||
Permission is hereby granted, free of charge, to any person obtaining a copy | ||
of this software and associated documentation files (the "Software"), to deal | ||
in the Software without restriction, including without limitation the rights | ||
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | ||
copies of the Software, and to permit persons to whom the Software is | ||
furnished to do so, subject to the following conditions: | ||
The above copyright notice and this permission notice shall be included in | ||
all copies or substantial portions of the Software. | ||
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | ||
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | ||
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | ||
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | ||
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, | ||
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | ||
SOFTWARE. | ||
``` |