3 files changed, 158 insertions, 3 deletions
diff --git a/drivers/gles3/shaders/SCsub b/drivers/gles3/shaders/SCsub
index 0fa0e3b73a..afffe10316 100644
--- a/drivers/gles3/shaders/SCsub
+++ b/drivers/gles3/shaders/SCsub
@@ -5,4 +5,5 @@ if env['BUILDERS'].has_key('GLES3_GLSL'):
 	env.GLES3_GLSL('canvas.glsl');
 	env.GLES3_GLSL('canvas_shadow.glsl');
 	env.GLES3_GLSL('scene.glsl');
+	env.GLES3_GLSL('cubemap_filter.glsl');
 
diff --git a/drivers/gles3/shaders/copy.glsl b/drivers/gles3/shaders/copy.glsl
index aba280186a..eb58d66431 100644
--- a/drivers/gles3/shaders/copy.glsl
+++ b/drivers/gles3/shaders/copy.glsl
@@ -33,20 +33,31 @@ void main() {
 
 #ifdef USE_CUBEMAP
 in vec3 cube_interp;
-uniform samplerCube source_cube;
+uniform samplerCube source_cube; //texunit:0
 #else
 in vec2 uv_interp;
-uniform sampler2D source;
+uniform sampler2D source; //texunit:0
 #endif
 
+
+uniform float stuff;
+
 in vec2 uv2_interp;
 
-layout(location = 0) vec4 frag_color; //color:0
+layout(location = 0) out vec4 frag_color;
 
 void main() {
 
 	//vec4 color = color_interp;
 
+#ifdef USE_CUBEMAP
+	vec4 color = texture( source_cube,  normalize(cube_interp) );
+
+#else
+	vec4 color = texture( source,  uv_interp );
+#endif
+
+
 	frag_color = color;
 }
 
diff --git a/drivers/gles3/shaders/cubemap_filter.glsl b/drivers/gles3/shaders/cubemap_filter.glsl
new file mode 100644
index 0000000000..f450f34113
--- /dev/null
+++ b/drivers/gles3/shaders/cubemap_filter.glsl
@@ -0,0 +1,143 @@
+[vertex]
+
+
+layout(location=0) in highp vec2 vertex;
+
+layout(location=1) in highp vec2 uv;
+
+out highp vec2 uv_interp;
+
+void main() {
+
+	uv_interp=uv;
+	gl_Position=vec4(vertex,0,1);
+}
+
+[fragment]
+
+
+uniform samplerCube source_cube; //texunit:1
+uniform int face_id;
+uniform float roughness;
+in highp vec2 uv_interp;
+
+
+layout(location = 0) vec4 frag_color;
+
+
+vec3 texelCoordToVec(vec2 uv, int faceID)
+{
+    mat3 faceUvVectors[6];
+
+    // -x
+    faceUvVectors[1][0] = vec3(0.0, 0.0, 1.0);  // u -> +z
+    faceUvVectors[1][1] = vec3(0.0, -1.0, 0.0); // v -> -y
+    faceUvVectors[1][2] = vec3(-1.0, 0.0, 0.0); // -x face
+
+    // +x
+    faceUvVectors[0][0] = vec3(0.0, 0.0, -1.0); // u -> -z
+    faceUvVectors[0][1] = vec3(0.0, -1.0, 0.0); // v -> -y
+    faceUvVectors[0][2] = vec3(1.0, 0.0, 0.0);  // +x face
+
+    // -y
+    faceUvVectors[3][0] = vec3(1.0, 0.0, 0.0);  // u -> +x
+    faceUvVectors[3][1] = vec3(0.0, 0.0, -1.0); // v -> -z
+    faceUvVectors[3][2] = vec3(0.0, -1.0, 0.0); // -y face
+
+    // +y
+    faceUvVectors[2][0] = vec3(1.0, 0.0, 0.0);  // u -> +x
+    faceUvVectors[2][1] = vec3(0.0, 0.0, 1.0);  // v -> +z
+    faceUvVectors[2][2] = vec3(0.0, 1.0, 0.0);  // +y face
+
+    // -z
+    faceUvVectors[5][0] = vec3(-1.0, 0.0, 0.0); // u -> -x
+    faceUvVectors[5][1] = vec3(0.0, -1.0, 0.0); // v -> -y
+    faceUvVectors[5][2] = vec3(0.0, 0.0, -1.0); // -z face
+
+    // +z
+    faceUvVectors[4][0] = vec3(1.0, 0.0, 0.0);  // u -> +x
+    faceUvVectors[4][1] = vec3(0.0, -1.0, 0.0); // v -> -y
+    faceUvVectors[4][2] = vec3(0.0, 0.0, 1.0);  // +z face
+
+    // out = u * s_faceUv[0] + v * s_faceUv[1] + s_faceUv[2].
+    vec3 result = (faceUvVectors[faceID][0] * uv.x) + (faceUvVectors[faceID][1] * uv.y) + faceUvVectors[faceID][2];
+    return normalize(result);
+}
+
+vec3 ImportanceSampleGGX(vec2 Xi, float Roughness, vec3 N)
+{
+	float a = Roughness * Roughness; // DISNEY'S ROUGHNESS [see Burley'12 siggraph]
+
+	// Compute distribution direction
+	float Phi = 2.0 * M_PI * Xi.x;
+	float CosTheta = sqrt((1.0 - Xi.y) / (1.0 + (a*a - 1.0) * Xi.y));
+	float SinTheta = sqrt(1.0 - CosTheta * CosTheta);
+
+	// Convert to spherical direction
+	vec3 H;
+	H.x = SinTheta * cos(Phi);
+	H.y = SinTheta * sin(Phi);
+	H.z = CosTheta;
+
+	vec3 UpVector = abs(N.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(1.0, 0.0, 0.0);
+	vec3 TangentX = normalize(cross(UpVector, N));
+	vec3 TangentY = cross(N, TangentX);
+
+	// Tangent to world space
+	return TangentX * H.x + TangentY * H.y + N * H.z;
+}
+
+// http://graphicrants.blogspot.com.au/2013/08/specular-brdf-reference.html
+float GGX(float NdotV, float a)
+{
+	float k = a / 2.0;
+	return NdotV / (NdotV * (1.0 - k) + k);
+}
+
+// http://graphicrants.blogspot.com.au/2013/08/specular-brdf-reference.html
+float G_Smith(float a, float nDotV, float nDotL)
+{
+	return GGX(nDotL, a * a) * GGX(nDotV, a * a);
+}
+
+float radicalInverse_VdC(uint bits) {
+    bits = (bits << 16u) | (bits >> 16u);
+    bits = ((bits & 0x55555555u) << 1u) | ((bits & 0xAAAAAAAAu) >> 1u);
+    bits = ((bits & 0x33333333u) << 2u) | ((bits & 0xCCCCCCCCu) >> 2u);
+    bits = ((bits & 0x0F0F0F0Fu) << 4u) | ((bits & 0xF0F0F0F0u) >> 4u);
+    bits = ((bits & 0x00FF00FFu) << 8u) | ((bits & 0xFF00FF00u) >> 8u);
+    return float(bits) * 2.3283064365386963e-10; // / 0x100000000
+}
+
+vec2 Hammersley(uint i, uint N) {
+     return vec2(float(i)/float(N), radicalInverse_VdC(i));
+}
+
+#define SAMPLE_COUNT 1024
+
+void main() {
+
+	vec2 uv         = (uv_interp * 2.0) - 1.0;
+	vec3 N          = texelCoordToVec(uv, face_id);
+
+	//vec4 color = color_interp;
+	vec4 sum = vec4(0.0, 0.0, 0.0, 0.0);
+
+	for(int sampleNum = 0; sampleNum < SAMPLE_COUNT; sampleNum++) {
+		vec2 xi = Hammersley(sampleNum, SAMPLE_COUNT);
+		vec2 xi = texture2DLod(Texture0, vec2(float(sampleNum) / float(SAMPLE_COUNT), 0.5), 0.0).xy;
+
+		vec3 H  = ImportanceSampleGGX( xi, roughness, N );
+		vec3 V  = N;
+		vec3 L  = normalize(2.0 * dot( V, H ) * H - V);
+
+		float ndotl = max(0.0, dot(N, L));
+		vec3 s = textureCubeLod(u_skyCube, H, 0.0).rgb * ndotl;
+
+		sum += vec4(s, 1.0);
+	}
+	sum /= sum.w;
+
+	frag_color = vec4(sum.rgb, 1.0);
+}
+