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wip procgen

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asrael 2025-11-09 06:30:17 -06:00
parent a653eae745
commit 79a678f162
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18 changed files with 1317 additions and 127 deletions
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src/pxl8_math.c
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@ -250,3 +250,70 @@ pxl8_mat4 pxl8_mat4_lookat(pxl8_vec3 eye, pxl8_vec3 center, pxl8_vec3 up) {
return mat;
}
pxl8_frustum pxl8_frustum_from_matrix(pxl8_mat4 vp) {
pxl8_frustum frustum;
const f32* m = vp.m;
frustum.planes[0].normal.x = m[3] - m[0];
frustum.planes[0].normal.y = m[7] - m[4];
frustum.planes[0].normal.z = m[11] - m[8];
frustum.planes[0].distance = m[15] - m[12];
frustum.planes[1].normal.x = m[3] + m[0];
frustum.planes[1].normal.y = m[7] + m[4];
frustum.planes[1].normal.z = m[11] + m[8];
frustum.planes[1].distance = m[15] + m[12];
frustum.planes[2].normal.x = m[3] + m[1];
frustum.planes[2].normal.y = m[7] + m[5];
frustum.planes[2].normal.z = m[11] + m[9];
frustum.planes[2].distance = m[15] + m[13];
frustum.planes[3].normal.x = m[3] - m[1];
frustum.planes[3].normal.y = m[7] - m[5];
frustum.planes[3].normal.z = m[11] - m[9];
frustum.planes[3].distance = m[15] - m[13];
frustum.planes[4].normal.x = m[3] - m[2];
frustum.planes[4].normal.y = m[7] - m[6];
frustum.planes[4].normal.z = m[11] - m[10];
frustum.planes[4].distance = m[15] - m[14];
frustum.planes[5].normal.x = m[3] + m[2];
frustum.planes[5].normal.y = m[7] + m[6];
frustum.planes[5].normal.z = m[11] + m[10];
frustum.planes[5].distance = m[15] + m[14];
for (i32 i = 0; i < 6; i++) {
f32 len = pxl8_vec3_length(frustum.planes[i].normal);
if (len > 1e-6f) {
f32 inv_len = 1.0f / len;
frustum.planes[i].normal = pxl8_vec3_scale(frustum.planes[i].normal, inv_len);
frustum.planes[i].distance *= inv_len;
}
}
return frustum;
}
bool pxl8_frustum_test_aabb(const pxl8_frustum* frustum, pxl8_vec3 min, pxl8_vec3 max) {
for (i32 i = 0; i < 6; i++) {
pxl8_vec3 normal = frustum->planes[i].normal;
f32 d = frustum->planes[i].distance;
pxl8_vec3 p_vertex = {
(normal.x >= 0.0f) ? max.x : min.x,
(normal.y >= 0.0f) ? max.y : min.y,
(normal.z >= 0.0f) ? max.z : min.z
};
f32 dist = pxl8_vec3_dot(normal, p_vertex) + d;
if (dist < 0.0f) {
return false;
}
}
return true;
}