Overlay Engine: Wireframe: Remove geometry shader and fragment discard

This Simplify and should also speedup the drawing a tiny bit.

We now discard the edges in the vertex shader by setting one of the verts
at vec4(0,0,0,0) to not produce any fragment

source/blender/draw/CMakeLists.txt

@@ -380,7 +380,6 @@ data_to_c_simple(engines/overlay/shaders/particle_frag.glsl SRC)
 data_to_c_simple(engines/overlay/shaders/sculpt_mask_vert.glsl SRC)
 data_to_c_simple(engines/overlay/shaders/volume_velocity_vert.glsl SRC)
 data_to_c_simple(engines/overlay/shaders/wireframe_vert.glsl SRC)
-data_to_c_simple(engines/overlay/shaders/wireframe_geom.glsl SRC)
 data_to_c_simple(engines/overlay/shaders/wireframe_frag.glsl SRC)
 
 list(APPEND INC

source/blender/draw/engines/overlay/overlay_shader.c

@@ -100,7 +100,6 @@ extern char datatoc_particle_frag_glsl[];
 extern char datatoc_sculpt_mask_vert_glsl[];
 extern char datatoc_volume_velocity_vert_glsl[];
 extern char datatoc_wireframe_vert_glsl[];
-extern char datatoc_wireframe_geom_glsl[];
 extern char datatoc_wireframe_frag_glsl[];
 
 extern char datatoc_gpu_shader_depth_only_frag_glsl[];
@@ -1216,10 +1215,6 @@ GPUShader *OVERLAY_shader_wireframe_select(void)
                                  datatoc_gpu_shader_common_obinfos_lib_glsl,
                                  datatoc_wireframe_vert_glsl,
                                  NULL},
-        .geom = (const char *[]){sh_cfg->lib,
-                                 datatoc_common_globals_lib_glsl,
-                                 datatoc_wireframe_geom_glsl,
-                                 NULL},
         .frag = (const char *[]){datatoc_gpu_shader_depth_only_frag_glsl, NULL},
         .defs = (const char *[]){sh_cfg->def, "#define SELECT_EDGES\n", NULL},
     });
@@ -1234,23 +1229,14 @@ GPUShader *OVERLAY_shader_wireframe(void)
   OVERLAY_Shaders *sh_data = &e_data.sh_data[draw_ctx->sh_cfg];
   if (!sh_data->wireframe) {
     sh_data->wireframe = GPU_shader_create_from_arrays({
-      .vert = (const char *[]){sh_cfg->lib,
-                               datatoc_common_view_lib_glsl,
-                               datatoc_common_globals_lib_glsl,
-                               datatoc_gpu_shader_common_obinfos_lib_glsl,
-                               datatoc_wireframe_vert_glsl,
-                               NULL},
-      .frag = (const char *[]){datatoc_common_view_lib_glsl, datatoc_wireframe_frag_glsl, NULL},
-      /* Apple drivers does not support wide wires. Use geometry shader as a workaround. */
-#if USE_GEOM_SHADER_WORKAROUND
-      .geom = (const char *[]){sh_cfg->lib,
-                               datatoc_common_globals_lib_glsl,
-                               datatoc_wireframe_geom_glsl,
-                               NULL},
-      .defs = (const char *[]){sh_cfg->def, "#define USE_GEOM\n", NULL},
-#else
-      .defs = (const char *[]){sh_cfg->def, NULL},
-#endif
+        .vert = (const char *[]){sh_cfg->lib,
+                                 datatoc_common_view_lib_glsl,
+                                 datatoc_common_globals_lib_glsl,
+                                 datatoc_gpu_shader_common_obinfos_lib_glsl,
+                                 datatoc_wireframe_vert_glsl,
+                                 NULL},
+        .frag = (const char *[]){datatoc_common_view_lib_glsl, datatoc_wireframe_frag_glsl, NULL},
+        .defs = (const char *[]){sh_cfg->def, NULL},
     });
   }
   return sh_data->wireframe;

source/blender/draw/engines/overlay/shaders/wireframe_frag.glsl

@@ -1,7 +1,5 @@
 
 in vec3 finalColor;
-flat in float edgeSharpness;
-
 flat in vec2 edgeStart;
 noperspective in vec2 edgePos;
 
@@ -10,10 +8,6 @@ layout(location = 1) out vec4 lineOutput;
 
 void main()
 {
-  if (edgeSharpness < 0.0) {
-    discard;
-  }
-
   lineOutput = pack_line_data(gl_FragCoord.xy, edgeStart, edgePos);
   fragColor.rgb = finalColor;
   fragColor.a = 1.0;

source/blender/draw/engines/overlay/shaders/wireframe_geom.glsl

@@ -1,61 +0,0 @@
-
-/* This shader is only used for edge selection and OSX workaround for large wires. */
-
-layout(lines) in;
-layout(triangle_strip, max_vertices = 4) out;
-
-in vec3 finalColor_g[];
-in float edgeSharpness_g[];
-
-#ifndef SELECT_EDGES
-out vec3 finalColor;
-flat out float edgeSharpness;
-
-flat out vec2 edgeStart;
-noperspective out vec2 edgePos;
-#endif
-
-void do_vertex(const int i, float coord, vec2 offset)
-{
-#ifndef SELECT_EDGES
-  /* TODO */
-  edgePos = edgeStart = vec2(0);
-  edgeSharpness = edgeSharpness_g[i];
-  finalColor = finalColor_g[i];
-#endif
-  gl_Position = gl_in[i].gl_Position;
-  /* Multiply offset by 2 because gl_Position range is [-1..1]. */
-  gl_Position.xy += offset * 2.0 * gl_Position.w;
-#ifdef USE_WORLD_CLIP_PLANES
-  world_clip_planes_set_clip_distance(gl_in[i].gl_ClipDistance);
-#endif
-  EmitVertex();
-}
-
-void main()
-{
-  vec2 ss_pos[2];
-  ss_pos[0] = gl_in[0].gl_Position.xy / gl_in[0].gl_Position.w;
-  ss_pos[1] = gl_in[1].gl_Position.xy / gl_in[1].gl_Position.w;
-
-  vec2 line = ss_pos[0] - ss_pos[1];
-  line = abs(line) * sizeViewport.xy;
-
-  float half_size = sizePixel * 0.5;
-
-  vec3 edge_ofs = vec3(half_size * sizeViewportInv.xy, 0.0);
-
-  bool horizontal = line.x > line.y;
-  edge_ofs = (horizontal) ? edge_ofs.zyz : edge_ofs.xzz;
-
-  if (edgeSharpness_g[0] < 0.0) {
-    return;
-  }
-
-  do_vertex(0, half_size, edge_ofs.xy);
-  do_vertex(0, -half_size, -edge_ofs.xy);
-  do_vertex(1, half_size, edge_ofs.xy);
-  do_vertex(1, -half_size, -edge_ofs.xy);
-
-  EndPrimitive();
-}

source/blender/draw/engines/overlay/shaders/wireframe_vert.glsl

@@ -1,37 +1,25 @@
 
 uniform float wireStepParam;
+uniform bool useColoring;
+uniform bool isTransform;
+uniform bool isObjectColor;
+uniform bool isRandomColor;
 
 in vec3 pos;
 in vec3 nor;
 in float wd; /* wiredata */
 
+#ifndef SELECT_EDGES
+out vec3 finalColor;
+flat out vec2 edgeStart;
+noperspective out vec2 edgePos;
+#endif
+
 float get_edge_sharpness(float wd)
 {
   return ((wd == 0.0) ? -1.5 : wd) + wireStepParam;
 }
 
-/* Geometry shader version */
-#if defined(SELECT_EDGES) || defined(USE_GEOM)
-out vec3 finalColor_g;
-out float edgeSharpness_g;
-
-#else /* USE_GEOM */
-
-flat out vec2 edgeStart;
-noperspective out vec2 edgePos;
-
-out vec3 finalColor;
-flat out float edgeSharpness;
-#  define finalColor_g finalColor
-#  define edgeSharpness_g edgeSharpness
-
-#endif /* SELECT_EDGES */
-
-uniform bool useColoring;
-uniform bool isTransform;
-uniform bool isObjectColor;
-uniform bool isRandomColor;
-
 void wire_color_get(out vec3 rim_col, out vec3 wire_col)
 {
   int flag = int(abs(ObjectInfo.w));
@@ -115,12 +103,14 @@ void main()
   vec3 wpos = point_object_to_world(pos);
   gl_Position = point_world_to_ndc(wpos);
 
-#if !(defined(SELECT_EDGES) || defined(USE_GEOM))
+  if (get_edge_sharpness(wd) < 0.0) {
+    /* Discard primitive. */
+    gl_Position = vec4(0.0);
+  }
+
+#ifndef SELECT_EDGES
   /* Convert to screen position [0..sizeVp]. */
   edgePos = edgeStart = ((gl_Position.xy / gl_Position.w) * 0.5 + 0.5) * sizeViewport.xy;
-#endif
-
-  edgeSharpness_g = get_edge_sharpness(wd);
 
   vec3 rim_col, wire_col;
   if (isObjectColor || isRandomColor) {
@@ -136,7 +126,8 @@ void main()
 
   vec3 final_front_col = mix(rim_col, wire_col, 0.4);
   vec3 final_rim_col = mix(rim_col, wire_col, 0.1);
-  finalColor_g = mix(final_rim_col, final_front_col, facing);
+  finalColor = mix(final_rim_col, final_front_col, facing);
+#endif
 
 #ifdef USE_WORLD_CLIP_PLANES
   world_clip_planes_calc_clip_distance(wpos);