Fix T62262: Light "Show Cone" & stereoscopy volumes broken by MSAA

Volume itself was working, but buggy. The issue was that transparent shapes
does not write to depth buffer. But the custom MSAA resolve shader discard
pixels that did not write to depth making them transparent.

Transparent passes should not be inside the MSAA passes, this is also
a matter of performance.

1 files changed, 19 insertions, 16 deletions

diff --git a/source/blender/draw/modes/object_mode.c b/source/blender/draw/modes/object_mode.c
index e5a98d4227b..67b4dc6c6bb 100644
--- a/source/blender/draw/modes/object_mode.c
+++ b/source/blender/draw/modes/object_mode.c
@@ -96,7 +96,7 @@ extern char datatoc_gpu_shader_3D_vert_glsl[];
 typedef struct OBJECT_PassList {
 	struct DRWPass *non_meshes[2];
 	struct DRWPass *image_empties[2];
-	struct DRWPass *spot_shapes[2];
+	struct DRWPass *transp_shapes[2];
 	struct DRWPass *ob_center;
 	struct DRWPass *outlines;
 	struct DRWPass *outlines_search;
@@ -160,7 +160,7 @@ typedef struct OBJECT_ShadingGroupList {
 	/* Reference only */
 	struct DRWPass *non_meshes;
 	struct DRWPass *image_empties;
-	struct DRWPass *spot_shapes;
+	struct DRWPass *transp_shapes;
 	struct DRWPass *bone_solid;
 	struct DRWPass *bone_outline;
 	struct DRWPass *bone_wire;
@@ -1260,12 +1260,6 @@ static void OBJECT_cache_init(void *vedata)
 		sgl->camera_clip_points = shgroup_distance_lines_instance(sgl->non_meshes, geom, draw_ctx->sh_cfg);
 		sgl->camera_mist_points = shgroup_distance_lines_instance(sgl->non_meshes, geom, draw_ctx->sh_cfg);
 
-		geom = DRW_cache_quad_get();
-		sgl->camera_stereo_plane = shgroup_instance_alpha(sgl->non_meshes, geom, draw_ctx->sh_cfg);
-
-		geom = DRW_cache_cube_get();
-		sgl->camera_stereo_volume = shgroup_instance_alpha(sgl->non_meshes, geom, draw_ctx->sh_cfg);
-
 		geom = DRW_cache_empty_cube_get();
 		sgl->camera_stereo_volume_wires = shgroup_instance(sgl->non_meshes, geom, draw_ctx->sh_cfg);
 
@@ -1376,25 +1370,33 @@ static void OBJECT_cache_init(void *vedata)
 		geom = DRW_cache_field_cone_limit_get();
 		sgl->field_cone_limit = shgroup_instance_scaled(sgl->non_meshes, geom, draw_ctx->sh_cfg);
 
-		/* Spot shapes */
+		/* Transparent Shapes */
 		state = DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_LESS_EQUAL | DRW_STATE_BLEND | DRW_STATE_CULL_FRONT;
-		sgl->spot_shapes = psl->spot_shapes[i] = DRW_pass_create("Spot Shape Pass", state);
+		sgl->transp_shapes = psl->transp_shapes[i] = DRW_pass_create("Transparent Shapes", state);
 
+		/* Spot cones */
 		geom = DRW_cache_light_spot_volume_get();
-		sgl->light_spot_volume = shgroup_instance_alpha(sgl->spot_shapes, geom, draw_ctx->sh_cfg);
+		sgl->light_spot_volume = shgroup_instance_alpha(sgl->transp_shapes, geom, draw_ctx->sh_cfg);
 
 		geom = DRW_cache_light_spot_square_volume_get();
-		sgl->light_spot_volume_rect = shgroup_instance_alpha(sgl->spot_shapes, geom, draw_ctx->sh_cfg);
+		sgl->light_spot_volume_rect = shgroup_instance_alpha(sgl->transp_shapes, geom, draw_ctx->sh_cfg);
 
 		geom = DRW_cache_light_spot_volume_get();
-		sgl->light_spot_volume_outside = shgroup_instance_alpha(sgl->spot_shapes, geom, draw_ctx->sh_cfg);
+		sgl->light_spot_volume_outside = shgroup_instance_alpha(sgl->transp_shapes, geom, draw_ctx->sh_cfg);
 		DRW_shgroup_state_disable(sgl->light_spot_volume_outside, DRW_STATE_CULL_FRONT);
 		DRW_shgroup_state_enable(sgl->light_spot_volume_outside, DRW_STATE_CULL_BACK);
 
 		geom = DRW_cache_light_spot_square_volume_get();
-		sgl->light_spot_volume_rect_outside = shgroup_instance_alpha(sgl->spot_shapes, geom, draw_ctx->sh_cfg);
+		sgl->light_spot_volume_rect_outside = shgroup_instance_alpha(sgl->transp_shapes, geom, draw_ctx->sh_cfg);
 		DRW_shgroup_state_disable(sgl->light_spot_volume_rect_outside, DRW_STATE_CULL_FRONT);
 		DRW_shgroup_state_enable(sgl->light_spot_volume_rect_outside, DRW_STATE_CULL_BACK);
+
+		/* Camera stereo volumes */
+		geom = DRW_cache_cube_get();
+		sgl->camera_stereo_volume = shgroup_instance_alpha(sgl->transp_shapes, geom, draw_ctx->sh_cfg);
+
+		geom = DRW_cache_quad_get();
+		sgl->camera_stereo_plane = shgroup_instance_alpha(sgl->non_meshes, geom, draw_ctx->sh_cfg);
 	}
 
 	{
@@ -3205,11 +3207,12 @@ static void OBJECT_draw_scene(void *vedata)
 
 	float clearcol[4] = {0.0f, 0.0f, 0.0f, 0.0f};
 
+	/* Don't draw Transparent passes in MSAA buffer. */
 //	DRW_draw_pass(psl->bone_envelope);  /* Never drawn in Object mode currently. */
+	DRW_draw_pass(stl->g_data->sgl.transp_shapes);
 
 	MULTISAMPLE_SYNC_ENABLE(dfbl, dtxl);
 
-	DRW_draw_pass(stl->g_data->sgl.spot_shapes);
 	DRW_draw_pass(stl->g_data->sgl.bone_solid);
 	DRW_draw_pass(stl->g_data->sgl.bone_wire);
 	DRW_draw_pass(stl->g_data->sgl.bone_outline);
@@ -3305,7 +3308,7 @@ static void OBJECT_draw_scene(void *vedata)
 			GPU_depth_range(0.0f, 0.01f);
 		}
 
-		DRW_draw_pass(stl->g_data->sgl_ghost.spot_shapes);
+		DRW_draw_pass(stl->g_data->sgl_ghost.transp_shapes);
 		DRW_draw_pass(stl->g_data->sgl_ghost.bone_solid);
 		DRW_draw_pass(stl->g_data->sgl_ghost.bone_wire);
 		DRW_draw_pass(stl->g_data->sgl_ghost.bone_outline);