Add An Opacity Slider to Overlay Wireframe

This patch adds an opacity slider to the wireframe overlay. The previous
wireframe in dense geometry scenes could be too dark and sometimes the
user just wants an impression of the geometry during modelling.

Reviewed By: Jeroen Bakker

Differential Revision: https://developer.blender.org/D7622

5 files changed, 11 insertions, 6 deletions

diff --git a/source/blender/draw/engines/overlay/overlay_engine.c b/source/blender/draw/engines/overlay/overlay_engine.c
index e49b2e45580..5188d338183 100644
--- a/source/blender/draw/engines/overlay/overlay_engine.c
+++ b/source/blender/draw/engines/overlay/overlay_engine.c
@@ -90,6 +90,7 @@ static void OVERLAY_engine_init(void *vedata)
                        V3D_OVERLAY_HIDE_BONES | V3D_OVERLAY_HIDE_OBJECT_XTRAS |
                        V3D_OVERLAY_HIDE_OBJECT_ORIGINS;
     pd->overlay.wireframe_threshold = v3d->overlay.wireframe_threshold;
+    pd->overlay.wireframe_opacity = v3d->overlay.wireframe_opacity;
   }
 
   if (v3d->shading.type == OB_WIRE) {
diff --git a/source/blender/draw/engines/overlay/overlay_private.h b/source/blender/draw/engines/overlay/overlay_private.h
index d5ba0a5423f..c259d9351f3 100644
--- a/source/blender/draw/engines/overlay/overlay_private.h
+++ b/source/blender/draw/engines/overlay/overlay_private.h
@@ -140,6 +140,7 @@ typedef struct OVERLAY_ShadingData {
   int zneg_flag;
   /** Wireframe */
   float wire_step_param;
+  float wire_opacity;
   /** Edit Curve */
   float edit_curve_normal_length;
   /** Edit Mesh */
diff --git a/source/blender/draw/engines/overlay/overlay_wireframe.c b/source/blender/draw/engines/overlay/overlay_wireframe.c
index 7d2939d101e..617dda56421 100644
--- a/source/blender/draw/engines/overlay/overlay_wireframe.c
+++ b/source/blender/draw/engines/overlay/overlay_wireframe.c
@@ -62,6 +62,7 @@ void OVERLAY_wireframe_cache_init(OVERLAY_Data *vedata)
   View3DShading *shading = &draw_ctx->v3d->shading;
 
   pd->shdata.wire_step_param = pd->overlay.wireframe_threshold - 254.0f / 255.0f;
+  pd->shdata.wire_opacity = pd->overlay.wireframe_opacity;
 
   bool is_wire_shmode = (shading->type == OB_WIRE);
   bool is_material_shmode = (shading->type > OB_SOLID);
@@ -95,6 +96,7 @@ void OVERLAY_wireframe_cache_init(OVERLAY_Data *vedata)
       DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo);
       DRW_shgroup_uniform_texture_ref(grp, "depthTex", depth_tx);
       DRW_shgroup_uniform_float_copy(grp, "wireStepParam", pd->shdata.wire_step_param);
+      DRW_shgroup_uniform_float_copy(grp, "wireOpacity", pd->shdata.wire_opacity);
       DRW_shgroup_uniform_bool_copy(grp, "useColoring", use_coloring);
       DRW_shgroup_uniform_bool_copy(grp, "isTransform", (G.moving & G_TRANSFORM_OBJ) != 0);
       DRW_shgroup_uniform_bool_copy(grp, "isObjectColor", is_object_color);
diff --git a/source/blender/draw/engines/overlay/shaders/wireframe_frag.glsl b/source/blender/draw/engines/overlay/shaders/wireframe_frag.glsl
index b5442dc1b0b..5c8c22c57d9 100644
--- a/source/blender/draw/engines/overlay/shaders/wireframe_frag.glsl
+++ b/source/blender/draw/engines/overlay/shaders/wireframe_frag.glsl
@@ -5,7 +5,7 @@ uniform sampler2D depthTex;
 flat in vec2 edgeStart;
 
 #ifndef SELECT_EDGES
-in vec3 finalColor;
+in vec4 finalColor;
 noperspective in vec2 edgePos;
 
 layout(location = 0) out vec4 fragColor;
@@ -22,8 +22,7 @@ void main()
 
 #ifndef SELECT_EDGES
   lineOutput = pack_line_data(gl_FragCoord.xy, edgeStart, edgePos);
-  fragColor.rgb = finalColor;
-  fragColor.a = 1.0;
+  fragColor = finalColor;
 
 #  ifdef CUSTOM_DEPTH_BIAS
   vec2 dir = lineOutput.xy * 2.0 - 1.0;
diff --git a/source/blender/draw/engines/overlay/shaders/wireframe_vert.glsl b/source/blender/draw/engines/overlay/shaders/wireframe_vert.glsl
index f7467aa3bf4..2950a66570f 100644
--- a/source/blender/draw/engines/overlay/shaders/wireframe_vert.glsl
+++ b/source/blender/draw/engines/overlay/shaders/wireframe_vert.glsl
@@ -1,5 +1,6 @@
 
 uniform float wireStepParam;
+uniform float wireOpacity;
 uniform bool useColoring;
 uniform bool isTransform;
 uniform bool isObjectColor;
@@ -14,7 +15,7 @@ in float wd; /* wiredata */
 flat out vec2 edgeStart;
 
 #ifndef SELECT_EDGES
-out vec3 finalColor;
+out vec4 finalColor;
 noperspective out vec2 edgePos;
 #endif
 
@@ -156,8 +157,9 @@ void main()
   rim_col = pow(rim_col, vec3(1.0 / 2.2));
   wire_col = pow(wire_col, vec3(1.0 / 2.2));
   vec3 final_front_col = mix(rim_col, wire_col, 0.35);
-  finalColor = mix(rim_col, final_front_col, facing);
-  finalColor = pow(finalColor, vec3(2.2));
+  finalColor.rgb = mix(rim_col, final_front_col, facing);
+  finalColor.rgb = pow(finalColor.rgb, vec3(2.2));
+  finalColor.a = wireOpacity;
 #endif
 
   /* Cull flat edges below threshold. */