Environment map shaders

Sources/Shaders/env_map.frag.glsl

@@ -0,0 +1,22 @@
+#ifdef GL_ES
+precision mediump float;
+#endif
+
+#define PI 3.1415926
+#define TwoPI (2.0 * PI)
+
+uniform sampler2D envmap;
+
+varying vec3 wcNormal;
+
+vec2 envMapEquirect(vec3 wcNormal, float flipEnvMap) {
+	float phi = acos(wcNormal.z);
+	float theta = atan(flipEnvMap * wcNormal.x, wcNormal.y) + PI;
+	return vec2(theta / TwoPI, phi / PI);
+}
+
+void kore() {
+
+	vec3 N = normalize(wcNormal);
+    gl_FragColor = texture2D(envmap, envMapEquirect(N, -1.0));
+}

Sources/Shaders/env_map.vert.glsl

@@ -0,0 +1,71 @@
+#ifdef GL_ES
+precision highp float;
+#endif
+
+uniform mat4 V;
+uniform mat4 P;
+
+attribute vec2 pos;
+
+varying vec3 wcNormal;
+
+mat4 inverse(mat4 m) {
+  float
+      a00 = m[0][0], a01 = m[0][1], a02 = m[0][2], a03 = m[0][3],
+      a10 = m[1][0], a11 = m[1][1], a12 = m[1][2], a13 = m[1][3],
+      a20 = m[2][0], a21 = m[2][1], a22 = m[2][2], a23 = m[2][3],
+      a30 = m[3][0], a31 = m[3][1], a32 = m[3][2], a33 = m[3][3],
+
+      b00 = a00 * a11 - a01 * a10,
+      b01 = a00 * a12 - a02 * a10,
+      b02 = a00 * a13 - a03 * a10,
+      b03 = a01 * a12 - a02 * a11,
+      b04 = a01 * a13 - a03 * a11,
+      b05 = a02 * a13 - a03 * a12,
+      b06 = a20 * a31 - a21 * a30,
+      b07 = a20 * a32 - a22 * a30,
+      b08 = a20 * a33 - a23 * a30,
+      b09 = a21 * a32 - a22 * a31,
+      b10 = a21 * a33 - a23 * a31,
+      b11 = a22 * a33 - a23 * a32,
+
+      det = b00 * b11 - b01 * b10 + b02 * b09 + b03 * b08 - b04 * b07 + b05 * b06;
+
+  return mat4(
+      a11 * b11 - a12 * b10 + a13 * b09,
+      a02 * b10 - a01 * b11 - a03 * b09,
+      a31 * b05 - a32 * b04 + a33 * b03,
+      a22 * b04 - a21 * b05 - a23 * b03,
+      a12 * b08 - a10 * b11 - a13 * b07,
+      a00 * b11 - a02 * b08 + a03 * b07,
+      a32 * b02 - a30 * b05 - a33 * b01,
+      a20 * b05 - a22 * b02 + a23 * b01,
+      a10 * b10 - a11 * b08 + a13 * b06,
+      a01 * b08 - a00 * b10 - a03 * b06,
+      a30 * b04 - a31 * b02 + a33 * b00,
+      a21 * b02 - a20 * b04 - a23 * b00,
+      a11 * b07 - a10 * b09 - a12 * b06,
+      a00 * b09 - a01 * b07 + a02 * b06,
+      a31 * b01 - a30 * b03 - a32 * b00,
+      a20 * b03 - a21 * b01 + a22 * b00) / det;
+}
+
+mat3 transpose(mat3 m) {
+  return mat3(m[0][0], m[1][0], m[2][0],
+              m[0][1], m[1][1], m[2][1],
+              m[0][2], m[1][2], m[2][2]);
+}
+
+void kore() {
+
+	mat4 invP = inverse(P);
+	mat3 invMV = transpose(mat3(V));
+
+	vec4 p = vec4(pos.xy, 0.0, 1.0);
+
+	vec3 unprojected = (invP * p).xyz;
+
+	wcNormal = invMV * unprojected;
+
+	gl_Position = vec4(pos.xy, 0.0, 1.0);
+}