Add FOV function

onnowhere · Apr 6, 2021 · 9abe85d · 9abe85d
1 parent 8855f2d
commit 9abe85d
Showing 1 changed file with 8 additions and 0 deletions.
diff --git a/.shader_utils/vsh_util.glsl b/.shader_utils/vsh_util.glsl
@@ -6,6 +6,14 @@
 #define LIGHT0_DIRECTION vec3(0.2, 1.0, -0.7) // Default light 0 direction everywhere except in inventory
 #define LIGHT1_DIRECTION vec3(-0.2, 1.0, 0.7) // Default light 1 direction everywhere except in nether and inventory
 
+/*
+ * Returns the FOV in degrees
+ * Calculates using the fact that top/near = tan(theta / 2)
+ */
+float getFOV(mat4 ProjMat) {
+    return atan(1.0, ProjMat[1][1]) * 114.591559;
+}
+
 /*
  * Returns if rendering in a GUI
  * In the GUI, near is 1000 and far is 3000, so -(far+near)/(far-near) = -2.0