Armature: Envelope: Revisit envelope drawing again.

Past shader was too slow and had bad artifacts. This method is much simpler
and eficient and only exhibit some popping when the raidus of the head/tail
is changed.

1 files changed, 10 insertions, 34 deletions

diff --git a/source/blender/draw/intern/draw_cache.c b/source/blender/draw/intern/draw_cache.c
index aa21bb7214a..be4c1783aff 100644
--- a/source/blender/draw/intern/draw_cache.c
+++ b/source/blender/draw/intern/draw_cache.c
@@ -85,7 +85,6 @@ static struct DRWShapeCache {
 	Gwn_Batch *drw_bone_box_wire;
 	Gwn_Batch *drw_bone_wire_wire;
 	Gwn_Batch *drw_bone_envelope;
-	Gwn_Batch *drw_bone_envelope_distance;
 	Gwn_Batch *drw_bone_envelope_outline;
 	Gwn_Batch *drw_bone_point;
 	Gwn_Batch *drw_bone_point_wire;
@@ -1881,20 +1880,18 @@ Gwn_Batch *DRW_cache_bone_wire_wire_outline_get(void)
  * Note that here we only encode head/tail in forth component of the vector. */
 static void benv_lat_lon_to_co(const float lat, const float lon, float r_nor[3])
 {
-	/* Poles are along Y axis. */
 	r_nor[0] = sinf(lat) * cosf(lon);
-	r_nor[1] = -cosf(lat);
-	r_nor[2] = sinf(lat) * sinf(lon);
+	r_nor[1] = sinf(lat) * sinf(lon);
+	r_nor[2] = cosf(lat);
 }
 
 Gwn_Batch *DRW_cache_bone_envelope_solid_get(void)
 {
 	if (!SHC.drw_bone_envelope) {
 		const int lon_res = 24;
-		const int lat_res = 16;
+		const int lat_res = 24;
 		const float lon_inc = 2.0f * M_PI / lon_res;
 		const float lat_inc = M_PI / lat_res;
-		const float eps = 0.02f;
 		unsigned int v_idx = 0;
 
 		static Gwn_VertFormat format = { 0 };
@@ -1905,14 +1902,16 @@ Gwn_Batch *DRW_cache_bone_envelope_solid_get(void)
 
 		/* Vertices */
 		Gwn_VertBuf *vbo = GWN_vertbuf_create_with_format(&format);
-		GWN_vertbuf_data_alloc(vbo, ((lat_res + 1) * 2) * lon_res * 2);
+		GWN_vertbuf_data_alloc(vbo, ((lat_res + 1) * 2) * lon_res * 1);
 
-		float lon = lon_inc;
+		float lon = 0.0f;
 		for (int i = 0; i < lon_res; i++, lon += lon_inc) {
 			float lat = 0.0f;
 			float co1[4], co2[4];
 			co1[3] = co2[3] = 0.0f;
 
+			/* Note: the poles are duplicated on purpose, to restart the strip. */
+
 			/* 1st sphere */
 			for (int j = 0; j < lat_res; j++, lat += lat_inc) {
 				benv_lat_lon_to_co(lat, lon,           co1);
@@ -1921,36 +1920,13 @@ Gwn_Batch *DRW_cache_bone_envelope_solid_get(void)
 				GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co1);
 				GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co2);
 			}
-			/* Need to close the sphere, but add a small gap to be able
-			 * to distinguish the verts in the vertex shader. */
-			benv_lat_lon_to_co(M_PI - eps, lon,           co1);
-			benv_lat_lon_to_co(M_PI - eps, lon + lon_inc, co2);
-			GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co1);
-			GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co2);
-
-			/* Add some precision to the middle part */
-			// co1[3] = co2[3] = 0.5f;
-			// co1[1] = co2[1] = 0.0f;
-			// GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co1);
-			// GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co2);
 
-			/* 2nd sphere */
-			co1[3] = co2[3] = 1.0f;
+			/* Closing the loop */
+			benv_lat_lon_to_co(M_PI, lon,           co1);
+			benv_lat_lon_to_co(M_PI, lon + lon_inc, co2);
 
-			/* Need to open the sphere */
-			benv_lat_lon_to_co(eps, lon,           co1);
-			benv_lat_lon_to_co(eps, lon + lon_inc, co2);
 			GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co1);
 			GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co2);
-
-			lat = lat_inc;
-			for (int j = 1; j < lat_res + 1; j++, lat += lat_inc) {
-				benv_lat_lon_to_co(lat, lon,           co1);
-				benv_lat_lon_to_co(lat, lon + lon_inc, co2);
-
-				GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co1);
-				GWN_vertbuf_attr_set(vbo, attr_id.pos, v_idx++, co2);
-			}
 		}
 
 		SHC.drw_bone_envelope = GWN_batch_create_ex(GWN_PRIM_TRI_STRIP, vbo, NULL, GWN_BATCH_OWNS_VBO);