Fix T77803: IK Degrees of freedom drawing glitch

IK degrees of freedom is rendered using wires and a solid sphere. The
solid used the wireframe drawing what resulted into drawing glitches.
This patch adds a new shader to draw the solid shape.

Reviewed By: Clément Foucault

Differential Revision: https://developer.blender.org/D8044

4 files changed, 35 insertions, 7 deletions

diff --git a/source/blender/draw/engines/overlay/overlay_armature.c b/source/blender/draw/engines/overlay/overlay_armature.c
index c65cdf48206..4bb9a74b2e2 100644
--- a/source/blender/draw/engines/overlay/overlay_armature.c
+++ b/source/blender/draw/engines/overlay/overlay_armature.c
@@ -228,11 +228,12 @@ void OVERLAY_armature_cache_init(OVERLAY_Data *vedata)
     {
       format = formats->instance_extra;
 
-      sh = OVERLAY_shader_armature_degrees_of_freedom();
+      sh = OVERLAY_shader_armature_degrees_of_freedom_wire();
       grp = DRW_shgroup_create(sh, armature_ps);
       DRW_shgroup_uniform_block_persistent(grp, "globalsBlock", G_draw.block_ubo);
       cb->dof_lines = BUF_INSTANCE(grp, format, DRW_cache_bone_dof_lines_get());
 
+      sh = OVERLAY_shader_armature_degrees_of_freedom_solid();
       grp = DRW_shgroup_create(sh, armature_transp_ps);
       DRW_shgroup_uniform_block_persistent(grp, "globalsBlock", G_draw.block_ubo);
       cb->dof_sphere = BUF_INSTANCE(grp, format, DRW_cache_bone_dof_sphere_get());
diff --git a/source/blender/draw/engines/overlay/overlay_private.h b/source/blender/draw/engines/overlay/overlay_private.h
index fdc421b29fb..53692a34a55 100644
--- a/source/blender/draw/engines/overlay/overlay_private.h
+++ b/source/blender/draw/engines/overlay/overlay_private.h
@@ -562,7 +562,8 @@ void OVERLAY_wireframe_draw(OVERLAY_Data *vedata);
 void OVERLAY_wireframe_in_front_draw(OVERLAY_Data *vedata);
 
 GPUShader *OVERLAY_shader_antialiasing(void);
-GPUShader *OVERLAY_shader_armature_degrees_of_freedom(void);
+GPUShader *OVERLAY_shader_armature_degrees_of_freedom_wire(void);
+GPUShader *OVERLAY_shader_armature_degrees_of_freedom_solid(void);
 GPUShader *OVERLAY_shader_armature_envelope(bool use_outline);
 GPUShader *OVERLAY_shader_armature_shape(bool use_outline);
 GPUShader *OVERLAY_shader_armature_shape_wire(void);
diff --git a/source/blender/draw/engines/overlay/overlay_shader.c b/source/blender/draw/engines/overlay/overlay_shader.c
index 0610b8397a1..ddb1a523140 100644
--- a/source/blender/draw/engines/overlay/overlay_shader.c
+++ b/source/blender/draw/engines/overlay/overlay_shader.c
@@ -130,7 +130,8 @@ extern char datatoc_common_view_lib_glsl[];
 
 typedef struct OVERLAY_Shaders {
   GPUShader *antialiasing;
-  GPUShader *armature_dof;
+  GPUShader *armature_dof_wire;
+  GPUShader *armature_dof_solid;
   GPUShader *armature_envelope_outline;
   GPUShader *armature_envelope_solid;
   GPUShader *armature_shape_outline;
@@ -473,13 +474,13 @@ GPUShader *OVERLAY_shader_armature_stick(void)
   return sh_data->armature_stick;
 }
 
-GPUShader *OVERLAY_shader_armature_degrees_of_freedom(void)
+GPUShader *OVERLAY_shader_armature_degrees_of_freedom_wire(void)
 {
   const DRWContextState *draw_ctx = DRW_context_state_get();
   const GPUShaderConfigData *sh_cfg = &GPU_shader_cfg_data[draw_ctx->sh_cfg];
   OVERLAY_Shaders *sh_data = &e_data.sh_data[draw_ctx->sh_cfg];
-  if (!sh_data->armature_dof) {
-    sh_data->armature_dof = GPU_shader_create_from_arrays({
+  if (!sh_data->armature_dof_wire) {
+    sh_data->armature_dof_wire = GPU_shader_create_from_arrays({
         .vert = (const char *[]){sh_cfg->lib,
                                  datatoc_common_globals_lib_glsl,
                                  datatoc_common_view_lib_glsl,
@@ -487,10 +488,31 @@ GPUShader *OVERLAY_shader_armature_degrees_of_freedom(void)
                                  NULL},
         .frag =
             (const char *[]){datatoc_common_view_lib_glsl, datatoc_armature_wire_frag_glsl, NULL},
+        .defs = (const char *[]){sh_cfg->def, "#define EDGE\n", NULL},
+    });
+  }
+  return sh_data->armature_dof_wire;
+}
+
+GPUShader *OVERLAY_shader_armature_degrees_of_freedom_solid(void)
+{
+  const DRWContextState *draw_ctx = DRW_context_state_get();
+  const GPUShaderConfigData *sh_cfg = &GPU_shader_cfg_data[draw_ctx->sh_cfg];
+  OVERLAY_Shaders *sh_data = &e_data.sh_data[draw_ctx->sh_cfg];
+  if (!sh_data->armature_dof_solid) {
+    sh_data->armature_dof_solid = GPU_shader_create_from_arrays({
+        .vert = (const char *[]){sh_cfg->lib,
+                                 datatoc_common_globals_lib_glsl,
+                                 datatoc_common_view_lib_glsl,
+                                 datatoc_armature_dof_vert_glsl,
+                                 NULL},
+        .frag = (const char *[]){datatoc_common_view_lib_glsl,
+                                 datatoc_gpu_shader_flat_color_frag_glsl,
+                                 NULL},
         .defs = (const char *[]){sh_cfg->def, NULL},
     });
   }
-  return sh_data->armature_dof;
+  return sh_data->armature_dof_solid;
 }
 
 GPUShader *OVERLAY_shader_armature_wire(void)
diff --git a/source/blender/draw/engines/overlay/shaders/armature_dof_vert.glsl b/source/blender/draw/engines/overlay/shaders/armature_dof_vert.glsl
index b15554bbb6a..18a80fc1fb4 100644
--- a/source/blender/draw/engines/overlay/shaders/armature_dof_vert.glsl
+++ b/source/blender/draw/engines/overlay/shaders/armature_dof_vert.glsl
@@ -8,8 +8,10 @@ in vec4 color;
 in mat4 inst_obmat;
 
 flat out vec4 finalColor;
+#ifdef EDGE
 flat out vec2 edgeStart;
 noperspective out vec2 edgePos;
+#endif
 
 vec3 sphere_project(float ax, float az)
 {
@@ -35,7 +37,9 @@ void main()
   gl_Position = point_world_to_ndc(world_pos);
   finalColor = color;
 
+#ifdef EDGE
   edgeStart = edgePos = ((gl_Position.xy / gl_Position.w) * 0.5 + 0.5) * sizeViewport.xy;
+#endif
 
 #ifdef USE_WORLD_CLIP_PLANES
   world_clip_planes_calc_clip_distance(world_pos);