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authorLaG1924 <12997935+LaG1924@users.noreply.github.com>2017-06-14 16:22:52 +0200
committerLaG1924 <12997935+LaG1924@users.noreply.github.com>2017-06-14 16:22:52 +0200
commitac8905602d1f221a71ddcdc86796344101276321 (patch)
tree21deaeb615d6789e7ddf14844cbf8faf0081af7e /src/graphics/Frustrum.cpp
parent2017-06-07 (diff)
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-rw-r--r--src/graphics/Frustrum.cpp111
1 files changed, 111 insertions, 0 deletions
diff --git a/src/graphics/Frustrum.cpp b/src/graphics/Frustrum.cpp
new file mode 100644
index 0000000..75f47c5
--- /dev/null
+++ b/src/graphics/Frustrum.cpp
@@ -0,0 +1,111 @@
+#include "Frustrum.hpp"
+
+enum FrustumSide {
+ RIGHT = 0, // The RIGHT side of the frustum
+ LEFT = 1, // The LEFT side of the frustum
+ BOTTOM = 2, // The BOTTOM side of the frustum
+ TOP = 3, // The TOP side of the frustum
+ BACK = 4, // The BACK side of the frustum
+ FRONT = 5 // The FRONT side of the frustum
+};
+
+enum PlaneData {
+ A = 0, // The X value of the plane's normal
+ B = 1, // The Y value of the plane's normal
+ C = 2, // The Z value of the plane's normal
+ D = 3 // The distance the plane is from the origin
+};
+
+void normalizePlane(glm::vec4 &frustum_plane) {
+ float magnitude = (float) sqrt(frustum_plane[A] * frustum_plane[A] + frustum_plane[B] * frustum_plane[B] +
+ frustum_plane[C] * frustum_plane[C]);
+ frustum_plane[A] /= magnitude;
+ frustum_plane[B] /= magnitude;
+ frustum_plane[C] /= magnitude;
+ frustum_plane[D] /= magnitude;
+}
+
+void Frustum::CalculateFrustum(glm::mat4 &view_matrix, glm::mat4 &proj_matrix) {
+ float proj[16];
+ float modl[16];
+ const float *projP = glm::value_ptr(proj_matrix);
+ const float *modlP = glm::value_ptr(view_matrix);
+ for (int i = 0; i < 16; i++) {
+ proj[i]=projP[i];
+ modl[i]=modlP[i];
+ }
+
+ float clip[16]; //clipping planes
+
+ clip[0] = modl[0] * proj[0] + modl[1] * proj[4] + modl[2] * proj[8] + modl[3] * proj[12];
+ clip[1] = modl[0] * proj[1] + modl[1] * proj[5] + modl[2] * proj[9] + modl[3] * proj[13];
+ clip[2] = modl[0] * proj[2] + modl[1] * proj[6] + modl[2] * proj[10] + modl[3] * proj[14];
+ clip[3] = modl[0] * proj[3] + modl[1] * proj[7] + modl[2] * proj[11] + modl[3] * proj[15];
+
+ clip[4] = modl[4] * proj[0] + modl[5] * proj[4] + modl[6] * proj[8] + modl[7] * proj[12];
+ clip[5] = modl[4] * proj[1] + modl[5] * proj[5] + modl[6] * proj[9] + modl[7] * proj[13];
+ clip[6] = modl[4] * proj[2] + modl[5] * proj[6] + modl[6] * proj[10] + modl[7] * proj[14];
+ clip[7] = modl[4] * proj[3] + modl[5] * proj[7] + modl[6] * proj[11] + modl[7] * proj[15];
+
+ clip[8] = modl[8] * proj[0] + modl[9] * proj[4] + modl[10] * proj[8] + modl[11] * proj[12];
+ clip[9] = modl[8] * proj[1] + modl[9] * proj[5] + modl[10] * proj[9] + modl[11] * proj[13];
+ clip[10] = modl[8] * proj[2] + modl[9] * proj[6] + modl[10] * proj[10] + modl[11] * proj[14];
+ clip[11] = modl[8] * proj[3] + modl[9] * proj[7] + modl[10] * proj[11] + modl[11] * proj[15];
+
+ clip[12] = modl[12] * proj[0] + modl[13] * proj[4] + modl[14] * proj[8] + modl[15] * proj[12];
+ clip[13] = modl[12] * proj[1] + modl[13] * proj[5] + modl[14] * proj[9] + modl[15] * proj[13];
+ clip[14] = modl[12] * proj[2] + modl[13] * proj[6] + modl[14] * proj[10] + modl[15] * proj[14];
+ clip[15] = modl[12] * proj[3] + modl[13] * proj[7] + modl[14] * proj[11] + modl[15] * proj[15];
+
+ frustum_planes[RIGHT][A] = clip[3] - clip[0];
+ frustum_planes[RIGHT][B] = clip[7] - clip[4];
+ frustum_planes[RIGHT][C] = clip[11] - clip[8];
+ frustum_planes[RIGHT][D] = clip[15] - clip[12];
+ normalizePlane(frustum_planes[RIGHT]);
+
+ frustum_planes[LEFT][A] = clip[3] + clip[0];
+ frustum_planes[LEFT][B] = clip[7] + clip[4];
+ frustum_planes[LEFT][C] = clip[11] + clip[8];
+ frustum_planes[LEFT][D] = clip[15] + clip[12];
+ normalizePlane(frustum_planes[LEFT]);
+
+ frustum_planes[BOTTOM][A] = clip[3] + clip[1];
+ frustum_planes[BOTTOM][B] = clip[7] + clip[5];
+ frustum_planes[BOTTOM][C] = clip[11] + clip[9];
+ frustum_planes[BOTTOM][D] = clip[15] + clip[13];
+ normalizePlane(frustum_planes[BOTTOM]);
+
+ frustum_planes[TOP][A] = clip[3] - clip[1];
+ frustum_planes[TOP][B] = clip[7] - clip[5];
+ frustum_planes[TOP][C] = clip[11] - clip[9];
+ frustum_planes[TOP][D] = clip[15] - clip[13];
+ normalizePlane(frustum_planes[TOP]);
+
+ frustum_planes[BACK][A] = clip[3] - clip[2];
+ frustum_planes[BACK][B] = clip[7] - clip[6];
+ frustum_planes[BACK][C] = clip[11] - clip[10];
+ frustum_planes[BACK][D] = clip[15] - clip[14];
+ normalizePlane(frustum_planes[BACK]);
+
+ frustum_planes[FRONT][A] = clip[3] + clip[2];
+ frustum_planes[FRONT][B] = clip[7] + clip[6];
+ frustum_planes[FRONT][C] = clip[11] + clip[10];
+ frustum_planes[FRONT][D] = clip[15] + clip[14];
+ normalizePlane(frustum_planes[FRONT]);
+}
+
+bool Frustum::TestInsideFrustrum(glm::vec4 Min, glm::vec4 Max) {
+ bool inside = true;
+ //test all 6 frustum planes
+ for (int i = 0; i < 6; i++) {
+ //pick closest point to plane and check if it behind the plane
+ //if yes - object outside frustum
+ float d = std::max(Min.x * frustum_planes[i].x, Max.x * frustum_planes[i].x)
+ + std::max(Min.y * frustum_planes[i].y, Max.y * frustum_planes[i].y)
+ + std::max(Min.z * frustum_planes[i].z, Max.z * frustum_planes[i].z)
+ + frustum_planes[i].w;
+ inside &= d > 0;
+ //return false; //with flag works faster
+ }
+ return inside;
+}