initial commit, 4.5 stable

servers/rendering/renderer_rd/shaders/effects/cubemap_roughness.glsl

@@ -0,0 +1,63 @@
+#[compute]
+
+#version 450
+
+#VERSION_DEFINES
+
+#define GROUP_SIZE 8
+
+layout(local_size_x = GROUP_SIZE, local_size_y = GROUP_SIZE, local_size_z = 1) in;
+
+layout(set = 0, binding = 0) uniform samplerCube source_cube;
+
+layout(rgba16f, set = 1, binding = 0) uniform restrict writeonly imageCube dest_cubemap;
+
+#include "cubemap_roughness_inc.glsl"
+
+void main() {
+	uvec3 id = gl_GlobalInvocationID;
+	id.z += params.face_id;
+
+	vec2 uv = ((vec2(id.xy) * 2.0 + 1.0) / (params.face_size) - 1.0);
+	vec3 N = texelCoordToVec(uv, id.z);
+
+	if (params.use_direct_write) {
+		imageStore(dest_cubemap, ivec3(id), vec4(texture(source_cube, N).rgb, 1.0));
+	} else {
+		vec4 sum = vec4(0.0, 0.0, 0.0, 0.0);
+
+		float solid_angle_texel = 4.0 * M_PI / (6.0 * params.face_size * params.face_size);
+		float roughness2 = params.roughness * params.roughness;
+		float roughness4 = roughness2 * roughness2;
+		vec3 UpVector = abs(N.z) < 0.999 ? vec3(0.0, 0.0, 1.0) : vec3(1.0, 0.0, 0.0);
+		mat3 T;
+		T[0] = normalize(cross(UpVector, N));
+		T[1] = cross(N, T[0]);
+		T[2] = N;
+
+		for (uint sampleNum = 0u; sampleNum < params.sample_count; sampleNum++) {
+			vec2 xi = Hammersley(sampleNum, params.sample_count);
+
+			vec3 H = T * ImportanceSampleGGX(xi, roughness4);
+			float NdotH = dot(N, H);
+			vec3 L = (2.0 * NdotH * H - N);
+
+			float ndotl = clamp(dot(N, L), 0.0, 1.0);
+
+			if (ndotl > 0.0) {
+				float D = DistributionGGX(NdotH, roughness4);
+				float pdf = D * NdotH / (4.0 * NdotH) + 0.0001;
+
+				float solid_angle_sample = 1.0 / (float(params.sample_count) * pdf + 0.0001);
+
+				float mipLevel = params.roughness == 0.0 ? 0.0 : 0.5 * log2(solid_angle_sample / solid_angle_texel);
+
+				sum.rgb += textureLod(source_cube, L, mipLevel).rgb * ndotl;
+				sum.a += ndotl;
+			}
+		}
+		sum /= sum.a;
+
+		imageStore(dest_cubemap, ivec3(id), vec4(sum.rgb, 1.0));
+	}
+}