Workbench: Add back studio lighting presets

This changes a bit how the userprefs solid lights works. They are not
visible until enabling the "Edit Solid Light" checkbox. Once enabled the
current studiolight used for solid mode will be overwritten.

Once the lighting settings are tweaked, the user can click the
"Save as Studio light" button to save the current settings.
This makes it easy to create new lighting without messing the other
presets.

The studio lights are stored as ASCII files on the disk using a dead
simple custom format.

The UI/UX is not perfect and will be improved in other commits.

Also includes:
* Separate LookDev HDRI selection from Solid Lights
* Hide LookDev HDRIs from the Solid Lights selection list

1 files changed, 50 insertions, 1 deletions

diff --git a/source/blender/draw/engines/workbench/workbench_studiolight.c b/source/blender/draw/engines/workbench/workbench_studiolight.c
index 901260d0660..183b285c69c 100644
--- a/source/blender/draw/engines/workbench/workbench_studiolight.c
+++ b/source/blender/draw/engines/workbench/workbench_studiolight.c
@@ -32,8 +32,56 @@
 #include "BLI_math.h"
 #include "BKE_global.h"
 
-void studiolight_update_world(StudioLight *sl, WORKBENCH_UBO_World *wd)
+void studiolight_update_world(WORKBENCH_PrivateData *wpd, StudioLight *studiolight, WORKBENCH_UBO_World *wd)
 {
+	float view_matrix[4][4], rot_matrix[4][4];
+	DRW_viewport_matrix_get(view_matrix, DRW_MAT_VIEW);
+
+	/* TODO enable when we support studiolight presets. */
+	if (STUDIOLIGHT_TYPE_WORLD_ENABLED(wpd) && false) {
+		axis_angle_to_mat4_single(rot_matrix, 'Y', -wpd->shading.studiolight_rot_z);
+		mul_m4_m4m4(rot_matrix, rot_matrix, view_matrix);
+		swap_v3_v3(rot_matrix[2], rot_matrix[1]);
+		negate_v3(rot_matrix[2]);
+	}
+	else {
+		unit_m4(rot_matrix);
+	}
+
+	if (U.edit_solid_light) {
+		studiolight = BKE_studiolight_studio_edit_get();
+	}
+
+	/* Studio Lights. */
+	for (int i = 0; i < 4; i++) {
+		WORKBENCH_UBO_Light *light = &wd->lights[i];
+		/* TODO use 4 lights in studiolights prefs. */
+		if (i > 2) {
+			copy_v3_fl3(light->light_direction, 1.0f, 0.0f, 0.0f);
+			copy_v3_fl(light->specular_color, 0.0f);
+			copy_v3_fl(light->diffuse_color, 0.0f);
+			continue;
+		}
+
+		SolidLight *sl = &studiolight->light[i];
+		if (sl->flag) {
+			copy_v3_v3(light->light_direction, sl->vec);
+			mul_mat3_m4_v3(rot_matrix, light->light_direction);
+			/* We should predivide the power by PI but that makes the lights really dim. */
+			copy_v3_v3(light->specular_color, sl->spec);
+			copy_v3_v3(light->diffuse_color, sl->col);
+			light->wrapped = sl->smooth;
+		}
+		else {
+			copy_v3_fl3(light->light_direction, 1.0f, 0.0f, 0.0f);
+			copy_v3_fl(light->specular_color, 0.0f);
+			copy_v3_fl(light->diffuse_color, 0.0f);
+		}
+	}
+
+	copy_v3_v3(wd->ambient_color, studiolight->light_ambient);
+
+#if 0
 	BKE_studiolight_ensure_flag(sl, STUDIOLIGHT_SPHERICAL_HARMONICS_COEFFICIENTS_CALCULATED);
 
 #if STUDIOLIGHT_SH_BANDS == 2
@@ -87,6 +135,7 @@ void studiolight_update_world(StudioLight *sl, WORKBENCH_UBO_World *wd)
 		copy_v3_v3(wd->spherical_harmonics_coefs[i], sl->spherical_harmonics_coefs[i]);
 	}
 #endif
+#endif
 }
 
 static void compute_parallel_lines_nor_and_dist(const float v1[2], const float v2[2], const float v3[2], float r_line[2])