[Bf-blender-cvs] [fa4201f82da] master: Fix T62701: Hair edit mode crashes on some old AMD Radeon drivers.

[mano-wii]

Commit: fa4201f82da5cd605af88195d1d98a256c678782
Author: mano-wii
Date:   Wed Apr 24 13:18:17 2019 -0300
Branches: master
https://developer.blender.org/rBfa4201f82da5cd605af88195d1d98a256c678782

Fix T62701: Hair edit mode crashes on some old AMD Radeon drivers.

The crash is related to the format, but the real reason is unknown.

===================================================================

M	source/blender/draw/intern/draw_cache_impl_particles.c
M	source/blender/draw/modes/shaders/particle_strand_vert.glsl

===================================================================

diff --git a/source/blender/draw/intern/draw_cache_impl_particles.c b/source/blender/draw/intern/draw_cache_impl_particles.c
index e998b17a44f..87ec2f19481 100644
--- a/source/blender/draw/intern/draw_cache_impl_particles.c
+++ b/source/blender/draw/intern/draw_cache_impl_particles.c
@@ -99,7 +99,7 @@ typedef struct HairAttributeID {
 
 typedef struct EditStrandData {
   float pos[3];
-  uchar color;
+  float color;
 } EditStrandData;
 
 static GPUVertFormat *edit_points_vert_format_get(uint *r_pos_id, uint *r_color_id)
@@ -110,7 +110,7 @@ static GPUVertFormat *edit_points_vert_format_get(uint *r_pos_id, uint *r_color_
     /* Keep in sync with EditStrandData */
     pos_id = GPU_vertformat_attr_add(&edit_point_format, "pos", GPU_COMP_F32, 3, GPU_FETCH_FLOAT);
     color_id = GPU_vertformat_attr_add(
-        &edit_point_format, "color", GPU_COMP_U8, 1, GPU_FETCH_INT_TO_FLOAT_UNIT);
+        &edit_point_format, "color", GPU_COMP_F32, 1, GPU_FETCH_FLOAT);
   }
   *r_pos_id = pos_id;
   *r_color_id = color_id;
@@ -693,12 +693,12 @@ static int particle_batch_cache_fill_segments_edit(
       float strand_t = (float)(j) / path->segments;
       if (particle) {
         float weight = particle_key_weight(particle, i, strand_t);
-        /* NaN or unclamped become 0xFF */
-        seg_data->color = (uchar)((weight <= 1.0f) ? 0xFE * weight : 0xFF);
+        /* NaN or unclamped become 1.0f */
+        seg_data->color = (weight < 1.0f) ? weight : 1.0f;
       }
       else {
         float selected = particle_key_select_ratio(edit, i, strand_t);
-        seg_data->color = (uchar)(0xFF * selected);
+        seg_data->color = selected;
       }
       GPU_indexbuf_add_generic_vert(elb, curr_point);
       curr_point++;
@@ -1565,7 +1565,7 @@ static void particle_batch_cache_ensure_edit_inner_pos(PTCacheEdit *edit,
     const PTCacheEditPoint *point = &edit->points[point_index];
     for (int key_index = 0; key_index < point->totkey - 1; key_index++) {
       PTCacheEditKey *key = &point->keys[key_index];
-      uchar color = (key->flag & PEK_SELECT) ? 0xFF : 0x00;
+      float color = (key->flag & PEK_SELECT) ? 1.0f : 0.0f;
       GPU_vertbuf_attr_set(cache->edit_inner_pos, pos_id, global_key_index, key->world_co);
       GPU_vertbuf_attr_set(cache->edit_inner_pos, color_id, global_key_index, &color);
       global_key_index++;
@@ -1611,7 +1611,8 @@ static void particle_batch_cache_ensure_edit_tip_pos(PTCacheEdit *edit, Particle
   for (int point_index = 0; point_index < edit->totpoint; point_index++) {
     const PTCacheEditPoint *point = &edit->points[point_index];
     PTCacheEditKey *key = &point->keys[point->totkey - 1];
-    uchar color = (key->flag & PEK_SELECT) ? 0xFF : 0x00;
+    float color = (key->flag & PEK_SELECT) ? 0.0f : 1.0f;
+
     GPU_vertbuf_attr_set(cache->edit_tip_pos, pos_id, point_index, key->world_co);
     GPU_vertbuf_attr_set(cache->edit_tip_pos, color_id, point_index, &color);
   }
diff --git a/source/blender/draw/modes/shaders/particle_strand_vert.glsl b/source/blender/draw/modes/shaders/particle_strand_vert.glsl
index 745499800e5..6dac6d6b980 100644
--- a/source/blender/draw/modes/shaders/particle_strand_vert.glsl
+++ b/source/blender/draw/modes/shaders/particle_strand_vert.glsl
@@ -45,14 +45,12 @@ vec3 weight_to_rgb(float weight)
   return r_rgb;
 }
 
-#define DECOMPRESS_RANGE 1.0039
-
 void main()
 {
   gl_Position = ModelViewProjectionMatrix * vec4(pos, 1.0);
 
 #ifdef USE_WEIGHT
-  finalColor = vec4(weight_to_rgb(color * DECOMPRESS_RANGE), 1.0);
+  finalColor = vec4(weight_to_rgb(color), 1.0);
 #else
   finalColor = mix(colorWire, colorEdgeSelect, color);
 #endif