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comparison trunk/chipmunkd/chipmunk.d @ 23:4ceef5833c8c

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updated to chipmunk 5.3.3
author Extrawurst
date Fri, 10 Dec 2010 02:10:27 +0100
parents df4ebc8add66
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22:ed2c81f3d1df 23:4ceef5833c8c
4 module chipmunkd.chipmunk; 4 module chipmunkd.chipmunk;
5 5
6 import std.stdio; 6 import std.stdio;
7 import std.string:format; 7 import std.string:format;
8 import std.conv:to; 8 import std.conv:to;
9 import std.math:PI;
9 10
10 void 11 void
11 cpMessage(string message, string condition, string file, int line, bool isError) 12 cpMessage(string message, string condition, string file, int line, bool isError)
12 { 13 {
13 stderr.writeln(.format("%s:%s", isError ? "Aborting due to Chipmunk error" : "Chipmunk warning", message)); 14 stderr.writeln(.format("%s:%s", isError ? "Aborting due to Chipmunk error" : "Chipmunk warning", message));
90 r1 and r2 are the inner and outer diameters. A solid circle has an inner diameter of 0. 91 r1 and r2 are the inner and outer diameters. A solid circle has an inner diameter of 0.
91 */ 92 */
92 cpFloat 93 cpFloat
93 cpMomentForCircle(cpFloat m, cpFloat r1, cpFloat r2, cpVect offset) 94 cpMomentForCircle(cpFloat m, cpFloat r1, cpFloat r2, cpVect offset)
94 { 95 {
95 return (1.0f/2.0f)*m*(r1*r1 + r2*r2) + m*cpvdot(offset, offset); 96 return m*(0.5f*(r1*r1 + r2*r2) + cpvlengthsq(offset));
96 } 97 }
98
99 /**
100 Calculate area of a hollow circle.
101 */
102 cpFloat cpAreaForCircle(cpFloat r1, cpFloat r2)
103 {
104 return 2.0f*cast(cpFloat)PI*cpfabs(r1*r1 - r2*r2);
105 }
106
97 /** 107 /**
98 Calculate the moment of inertia for a line segment. 108 Calculate the moment of inertia for a line segment.
99 Beveling radius is not supported. 109 Beveling radius is not supported.
100 */ 110 */
101 cpFloat 111 cpFloat
102 cpMomentForSegment(cpFloat m, cpVect a, cpVect b) 112 cpMomentForSegment(cpFloat m, cpVect a, cpVect b)
103 { 113 {
104 cpFloat length = cpvlength(cpvsub(b, a)); 114 cpFloat length = cpvlength(cpvsub(b, a));
105 cpVect offset = cpvmult(cpvadd(a, b), 1.0f/2.0f); 115 cpVect offset = cpvmult(cpvadd(a, b), 1.0f/2.0f);
106 116
107 return m*length*length/12.0f + m*cpvdot(offset, offset); 117 return m*(length*length/12.0f + cpvlengthsq(offset));
118 }
119
120 /**
121 Calculate the area of a fattened (capsule shaped) line segment.
122 */
123 cpFloat
124 cpAreaForSegment(cpVect a, cpVect b, cpFloat r)
125 {
126 return 2.0f*r*(cast(cpFloat)PI*r + cpvdist(a, b));
108 } 127 }
109 128
110 /** 129 /**
111 Calculate the moment of inertia for a solid polygon shape. 130 Calculate the moment of inertia for a solid polygon shape.
112 */ 131 */
133 cpfree(tVerts); 152 cpfree(tVerts);
134 return (m*sum1)/(6.0f*sum2); 153 return (m*sum1)/(6.0f*sum2);
135 } 154 }
136 155
137 /** 156 /**
157 Calculate the signed area of a polygon.
158 */
159 cpFloat cpAreaForPoly(const int numVerts, const cpVect *verts)
160 {
161 cpFloat area = 0.0f;
162 for(int i=0; i<numVerts; i++){
163 area += cpvcross(verts[i], verts[(i+1)%numVerts]);
164 }
165
166 return area/2.0f;
167 }
168
169 /**
170 Calculate the natural centroid of a polygon.
171 */
172 cpVect cpCentroidForPoly(const int numVerts, const cpVect *verts)
173 {
174 cpFloat sum = 0.0f;
175 cpVect vsum = cpvzero;
176
177 for(int i=0; i<numVerts; i++){
178 cpVect v1 = verts[i];
179 cpVect v2 = verts[(i+1)%numVerts];
180 cpFloat cross = cpvcross(v1, v2);
181
182 sum += cross;
183 vsum = cpvadd(vsum, cpvmult(cpvadd(v1, v2), cross));
184 }
185
186 return cpvmult(vsum, 1.0f/(3.0f*sum));
187 }
188
189 /**
190 Center the polygon on the origin. (Subtracts the centroid of the polygon from each vertex)
191 */
192 void cpRecenterPoly(const int numVerts, cpVect *verts)
193 {
194 cpVect centroid = cpCentroidForPoly(numVerts, verts);
195
196 for(int i=0; i<numVerts; i++){
197 verts[i] = cpvsub(verts[i], centroid);
198 }
199 }
200
201 /**
138 Calculate the moment of inertia for a solid box. 202 Calculate the moment of inertia for a solid box.
139 */ 203 */
140 cpFloat 204 cpFloat
141 cpMomentForBox(cpFloat m, cpFloat width, cpFloat height) 205 cpMomentForBox(cpFloat m, cpFloat width, cpFloat height)
142 { 206 {