Studiolight: Spherical harmonics

Compile time option to reduce the level of the SH

5 files changed, 26 insertions, 6 deletions

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_data_lib.glsl b/source/blender/draw/engines/workbench/shaders/workbench_data_lib.glsl
index 2ba6e0e8e55..2d913c63b00 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_data_lib.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_data_lib.glsl
@@ -4,7 +4,7 @@ struct LightData {
 };
 
 struct WorldData {
-	vec3 spherical_harmonics_coefs[9];
+	vec3 spherical_harmonics_coefs[STUDIOLIGHT_SPHERICAL_HARMONICS_MAX_COMPONENTS];
 	vec4 background_color_low;
 	vec4 background_color_high;
 	vec4 object_outline_color;
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_world_light_lib.glsl b/source/blender/draw/engines/workbench/shaders/workbench_world_light_lib.glsl
index 71adc751f0a..b13c4f1b43b 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_world_light_lib.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_world_light_lib.glsl
@@ -1,32 +1,36 @@
 #define BLINN
 
-vec3 spherical_harmonics_L2(vec3 N, vec3 spherical_harmonics_coefs[9])
+vec3 spherical_harmonics(vec3 N, vec3 spherical_harmonics_coefs[STUDIOLIGHT_SPHERICAL_HARMONICS_MAX_COMPONENTS])
 {
 	vec3 sh = vec3(0.0);
 
 	sh += 0.282095 * spherical_harmonics_coefs[0];
 
+#if STUDIOLIGHT_SPHERICAL_HARMONICS_LEVEL > 0
 	sh += -0.488603 * N.z * spherical_harmonics_coefs[1];
 	sh += 0.488603 * N.y * spherical_harmonics_coefs[2];
 	sh += -0.488603 * N.x * spherical_harmonics_coefs[3];
+#endif
 
+#if STUDIOLIGHT_SPHERICAL_HARMONICS_LEVEL > 1
 	sh += 1.092548 * N.x * N.z * spherical_harmonics_coefs[4];
 	sh += -1.092548 * N.z * N.y * spherical_harmonics_coefs[5];
 	sh += 0.315392 * (3.0 * N.y * N.y - 1.0) * spherical_harmonics_coefs[6];
 	sh += -1.092548 * N.x * N.y * spherical_harmonics_coefs[7];
 	sh += 0.546274 * (N.x * N.x - N.z * N.z) * spherical_harmonics_coefs[8];
+#endif
 
 	return sh;
 }
 
 vec3 get_world_diffuse_light(WorldData world_data, vec3 N)
 {
-	return (spherical_harmonics_L2(vec3(N.x, N.y, -N.z), world_data.spherical_harmonics_coefs));
+	return (spherical_harmonics(vec3(N.x, N.y, -N.z), world_data.spherical_harmonics_coefs));
 }
 
 vec3 get_camera_diffuse_light(WorldData world_data, vec3 N)
 {
-	return (spherical_harmonics_L2(vec3(N.x, -N.z, -N.y), world_data.spherical_harmonics_coefs));
+	return (spherical_harmonics(vec3(N.x, -N.z, -N.y), world_data.spherical_harmonics_coefs));
 }
 
 /* N And I are in View Space. */
diff --git a/source/blender/draw/engines/workbench/workbench_materials.c b/source/blender/draw/engines/workbench/workbench_materials.c
index 231d9a9582a..c0857cf74aa 100644
--- a/source/blender/draw/engines/workbench/workbench_materials.c
+++ b/source/blender/draw/engines/workbench/workbench_materials.c
@@ -95,6 +95,17 @@ char *workbench_material_build_defines(WORKBENCH_PrivateData *wpd, int drawtype,
 		BLI_dynstr_appendf(ds, "#define HAIR_SHADER\n");
 	}
 
+#if STUDIOLIGHT_SPHERICAL_HARMONICS_LEVEL == 0
+	BLI_dynstr_appendf(ds, "#define STUDIOLIGHT_SPHERICAL_HARMONICS_LEVEL 0\n");
+#endif
+#if STUDIOLIGHT_SPHERICAL_HARMONICS_LEVEL == 1
+	BLI_dynstr_appendf(ds, "#define STUDIOLIGHT_SPHERICAL_HARMONICS_LEVEL 1\n");
+#endif
+#if STUDIOLIGHT_SPHERICAL_HARMONICS_LEVEL == 2
+	BLI_dynstr_appendf(ds, "#define STUDIOLIGHT_SPHERICAL_HARMONICS_LEVEL 2\n");
+#endif
+	BLI_dynstr_appendf(ds, "#define STUDIOLIGHT_SPHERICAL_HARMONICS_MAX_COMPONENTS 9\n");
+
 	str = BLI_dynstr_get_cstring(ds);
 	BLI_dynstr_free(ds);
 	return str;
diff --git a/source/blender/draw/engines/workbench/workbench_private.h b/source/blender/draw/engines/workbench/workbench_private.h
index 9e43a5c4a48..68d50a85c35 100644
--- a/source/blender/draw/engines/workbench/workbench_private.h
+++ b/source/blender/draw/engines/workbench/workbench_private.h
@@ -112,7 +112,7 @@ typedef struct WORKBENCH_UBO_Light {
 } WORKBENCH_UBO_Light;
 
 typedef struct WORKBENCH_UBO_World {
-	float spherical_harmonics_coefs[9][4];
+	float spherical_harmonics_coefs[STUDIOLIGHT_SPHERICAL_HARMONICS_MAX_COMPONENTS][4];
 	float background_color_low[4];
 	float background_color_high[4];
 	float object_outline_color[4];
diff --git a/source/blender/draw/engines/workbench/workbench_studiolight.c b/source/blender/draw/engines/workbench/workbench_studiolight.c
index f2453bf7070..f9e5df91388 100644
--- a/source/blender/draw/engines/workbench/workbench_studiolight.c
+++ b/source/blender/draw/engines/workbench/workbench_studiolight.c
@@ -34,10 +34,15 @@
 
 void studiolight_update_world(StudioLight *sl, WORKBENCH_UBO_World *wd)
 {
+	int i;
 	BKE_studiolight_ensure_flag(sl, STUDIOLIGHT_SPHERICAL_HARMONICS_COEFFICIENTS_CALCULATED);
-	for (int i = 0; i < 9; i++) {
+
+	for (i = 0; i < STUDIOLIGHT_SPHERICAL_HARMONICS_COMPONENTS; i++) {
 		copy_v3_v3(wd->spherical_harmonics_coefs[i], sl->spherical_harmonics_coefs[i]);
 	}
+	for (; i < STUDIOLIGHT_SPHERICAL_HARMONICS_MAX_COMPONENTS; i++) {
+		copy_v3_fl(wd->spherical_harmonics_coefs[i], 0.0);
+	}
 }
 
 static void compute_parallel_lines_nor_and_dist(const float v1[2], const float v2[2], const float v3[2], float r_line[2])