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/* Copyright (c) 2007 Scott Lembcke
*
* 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.
*/
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include "chipmunk.h"
cpPolyShape *
cpPolyShapeAlloc(void)
{
return (cpPolyShape *)calloc(1, sizeof(cpPolyShape));
}
static void
cpPolyShapeTransformVerts(cpPolyShape *poly, cpVect p, cpVect rot)
{
cpVect *src = poly->verts;
cpVect *dst = poly->tVerts;
for(int i=0; i<poly->numVerts; i++)
dst[i] = cpvadd(p, cpvrotate(src[i], rot));
}
static void
cpPolyShapeTransformAxes(cpPolyShape *poly, cpVect p, cpVect rot)
{
cpPolyShapeAxis *src = poly->axes;
cpPolyShapeAxis *dst = poly->tAxes;
for(int i=0; i<poly->numVerts; i++){
cpVect n = cpvrotate(src[i].n, rot);
dst[i].n = n;
dst[i].d = cpvdot(p, n) + src[i].d;
}
}
static cpBB
cpPolyShapeCacheData(cpShape *shape, cpVect p, cpVect rot)
{
cpPolyShape *poly = (cpPolyShape *)shape;
cpFloat l, b, r, t;
cpPolyShapeTransformAxes(poly, p, rot);
cpPolyShapeTransformVerts(poly, p, rot);
cpVect *verts = poly->tVerts;
l = r = verts[0].x;
b = t = verts[0].y;
for(int i=1; i<poly->numVerts; i++){
cpVect v = verts[i];
l = cpfmin(l, v.x);
r = cpfmax(r, v.x);
b = cpfmin(b, v.y);
t = cpfmax(t, v.y);
}
return cpBBNew(l, b, r, t);
}
static void
cpPolyShapeDestroy(cpShape *shape)
{
cpPolyShape *poly = (cpPolyShape *)shape;
free(poly->verts);
free(poly->tVerts);
free(poly->axes);
free(poly->tAxes);
}
cpPolyShape *
cpPolyShapeInit(cpPolyShape *poly, cpBody *body, int numVerts, cpVect *verts, cpVect offset)
{
poly->numVerts = numVerts;
poly->verts = (cpVect *)calloc(numVerts, sizeof(cpVect));
poly->tVerts = (cpVect *)calloc(numVerts, sizeof(cpVect));
poly->axes = (cpPolyShapeAxis *)calloc(numVerts, sizeof(cpPolyShapeAxis));
poly->tAxes = (cpPolyShapeAxis *)calloc(numVerts, sizeof(cpPolyShapeAxis));
for(int i=0; i<numVerts; i++){
cpVect a = cpvadd(offset, verts[i]);
cpVect b = cpvadd(offset, verts[(i+1)%numVerts]);
cpVect n = cpvnormalize(cpvperp(cpvsub(b, a)));
poly->verts[i] = a;
poly->axes[i].n = n;
poly->axes[i].d = cpvdot(n, a);
}
poly->shape.cacheData = &cpPolyShapeCacheData;
poly->shape.destroy = &cpPolyShapeDestroy;
cpShapeInit((cpShape *)poly, CP_POLY_SHAPE, body);
return poly;
}
cpShape *
cpPolyShapeNew(cpBody *body, int numVerts, cpVect *verts, cpVect offset)
{
return (cpShape *)cpPolyShapeInit(cpPolyShapeAlloc(), body, numVerts, verts, offset);
}
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