9 static float projmatrix[16];
10 static float mvmatrix[16];
11 static float clip[16];
14 glGetFloatv(GL_PROJECTION_MATRIX, projmatrix);
15 glGetFloatv(GL_MODELVIEW_MATRIX, mvmatrix);
17 // Combine the matrices
18 clip[0] = mvmatrix[0] * projmatrix[0] + mvmatrix[1] * projmatrix[4] + mvmatrix[2] * projmatrix[8] + mvmatrix[3] * projmatrix[12];
19 clip[1] = mvmatrix[0] * projmatrix[1] + mvmatrix[1] * projmatrix[5] + mvmatrix[2] * projmatrix[9] + mvmatrix[3] * projmatrix[13];
20 clip[2] = mvmatrix[0] * projmatrix[2] + mvmatrix[1] * projmatrix[6] + mvmatrix[2] * projmatrix[10] + mvmatrix[3] * projmatrix[14];
21 clip[3] = mvmatrix[0] * projmatrix[3] + mvmatrix[1] * projmatrix[7] + mvmatrix[2] * projmatrix[11] + mvmatrix[3] * projmatrix[15];
23 clip[4] = mvmatrix[4] * projmatrix[0] + mvmatrix[5] * projmatrix[4] + mvmatrix[6] * projmatrix[8] + mvmatrix[7] * projmatrix[12];
24 clip[5] = mvmatrix[4] * projmatrix[1] + mvmatrix[5] * projmatrix[5] + mvmatrix[6] * projmatrix[9] + mvmatrix[7] * projmatrix[13];
25 clip[6] = mvmatrix[4] * projmatrix[2] + mvmatrix[5] * projmatrix[6] + mvmatrix[6] * projmatrix[10] + mvmatrix[7] * projmatrix[14];
26 clip[7] = mvmatrix[4] * projmatrix[3] + mvmatrix[5] * projmatrix[7] + mvmatrix[6] * projmatrix[11] + mvmatrix[7] * projmatrix[15];
28 clip[8] = mvmatrix[8] * projmatrix[0] + mvmatrix[9] * projmatrix[4] + mvmatrix[10] * projmatrix[8] + mvmatrix[11] * projmatrix[12];
29 clip[9] = mvmatrix[8] * projmatrix[1] + mvmatrix[9] * projmatrix[5] + mvmatrix[10] * projmatrix[9] + mvmatrix[11] * projmatrix[13];
30 clip[10] = mvmatrix[8] * projmatrix[2] + mvmatrix[9] * projmatrix[6] + mvmatrix[10] * projmatrix[10] + mvmatrix[11] * projmatrix[14];
31 clip[11] = mvmatrix[8] * projmatrix[3] + mvmatrix[9] * projmatrix[7] + mvmatrix[10] * projmatrix[11] + mvmatrix[11] * projmatrix[15];
33 clip[12] = mvmatrix[12] * projmatrix[0] + mvmatrix[13] * projmatrix[4] + mvmatrix[14] * projmatrix[8] + mvmatrix[15] * projmatrix[12];
34 clip[13] = mvmatrix[12] * projmatrix[1] + mvmatrix[13] * projmatrix[5] + mvmatrix[14] * projmatrix[9] + mvmatrix[15] * projmatrix[13];
35 clip[14] = mvmatrix[12] * projmatrix[2] + mvmatrix[13] * projmatrix[6] + mvmatrix[14] * projmatrix[10] + mvmatrix[15] * projmatrix[14];
36 clip[15] = mvmatrix[12] * projmatrix[3] + mvmatrix[13] * projmatrix[7] + mvmatrix[14] * projmatrix[11] + mvmatrix[15] * projmatrix[15];
39 frustum[0][0] = clip[3] - clip[0];
40 frustum[0][1] = clip[7] - clip[4];
41 frustum[0][2] = clip[11] - clip[8];
42 frustum[0][3] = clip[15] - clip[12];
45 frustum[1][0] = clip[3] + clip[0];
46 frustum[1][1] = clip[7] + clip[4];
47 frustum[1][2] = clip[11] + clip[8];
48 frustum[1][3] = clip[15] + clip[12];
51 frustum[2][0] = clip[3] + clip[1];
52 frustum[2][1] = clip[7] + clip[5];
53 frustum[2][2] = clip[11] + clip[9];
54 frustum[2][3] = clip[15] + clip[13];
57 frustum[3][0] = clip[3] - clip[1];
58 frustum[3][1] = clip[7] - clip[5];
59 frustum[3][2] = clip[11] - clip[9];
60 frustum[3][3] = clip[15] - clip[13];
63 frustum[4][0] = clip[3] - clip[2];
64 frustum[4][1] = clip[7] - clip[6];
65 frustum[4][2] = clip[11] - clip[10];
66 frustum[4][3] = clip[15] - clip[14];
69 frustum[5][0] = clip[3] + clip[2];
70 frustum[5][1] = clip[7] + clip[6];
71 frustum[5][2] = clip[11] + clip[10];
72 frustum[5][3] = clip[15] + clip[14];
76 CubeInFrustum(float x, float y, float z, float size) {
79 for(int i=0; i<6; i++) {
81 if(frustum[i][0] * (x-size) + frustum[i][1] * (y-size) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
83 if(frustum[i][0] * (x+size) + frustum[i][1] * (y-size) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
85 if(frustum[i][0] * (x-size) + frustum[i][1] * (y+size) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
87 if(frustum[i][0] * (x+size) + frustum[i][1] * (y+size) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
89 if(frustum[i][0] * (x-size) + frustum[i][1] * (y-size) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
91 if(frustum[i][0] * (x+size) + frustum[i][1] * (y-size) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
93 if(frustum[i][0] * (x-size) + frustum[i][1] * (y+size) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
95 if(frustum[i][0] * (x+size) + frustum[i][1] * (y+size) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
109 CubeInFrustum(float x, float y, float z, float size, float height) {
112 for(int i=0; i<6; i++) {
114 if(frustum[i][0] * (x-size) + frustum[i][1] * (y-height) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
116 if(frustum[i][0] * (x+size) + frustum[i][1] * (y-height) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
118 if(frustum[i][0] * (x-size) + frustum[i][1] * (y+height) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
120 if(frustum[i][0] * (x+size) + frustum[i][1] * (y+height) + frustum[i][2] * (z-size) + frustum[i][3] > 0)
122 if(frustum[i][0] * (x-size) + frustum[i][1] * (y-height) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
124 if(frustum[i][0] * (x+size) + frustum[i][1] * (y-height) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
126 if(frustum[i][0] * (x-size) + frustum[i][1] * (y+height) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
128 if(frustum[i][0] * (x+size) + frustum[i][1] * (y+height) + frustum[i][2] * (z+size) + frustum[i][3] > 0)
142 SphereInFrustum(float x, float y, float z, float radius) {
145 for(int i=0; i<6; i++) {
146 if(frustum[i][0] * x + frustum[i][1] * y + frustum[i][2] * z + frustum[i][3] > -1*radius)