1 files changed, 47 insertions, 0 deletions
diff --git a/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl b/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
index 59a463f49c3..c0d7719180b 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_common_lib.glsl
@@ -140,6 +140,28 @@ vec2 matcap_uv_compute(vec3 I, vec3 N, bool flipped)
   return matcap_uv * 0.496 + 0.5;
 }
 
+bool node_tex_tile_lookup(inout vec3 co, sampler2DArray ima, sampler1DArray map)
+{
+  vec2 tile_pos = floor(co.xy);
+
+  if (tile_pos.x < 0 || tile_pos.y < 0 || tile_pos.x >= 10)
+    return false;
+
+  float tile = 10.0 * tile_pos.y + tile_pos.x;
+  if (tile >= textureSize(map, 0).x)
+    return false;
+
+  /* Fetch tile information. */
+  float tile_layer = texelFetch(map, ivec2(tile, 0), 0).x;
+  if (tile_layer < 0.0)
+    return false;
+
+  vec4 tile_info = texelFetch(map, ivec2(tile, 1), 0);
+
+  co = vec3(((co.xy - tile_pos) * tile_info.zw) + tile_info.xy, tile_layer);
+  return true;
+}
+
 vec4 workbench_sample_texture(sampler2D image,
                               vec2 coord,
                               bool nearest_sampling,
@@ -158,3 +180,28 @@ vec4 workbench_sample_texture(sampler2D image,
 
   return color;
 }
+
+vec4 workbench_sample_texture_array(sampler2DArray tile_array,
+                                    sampler1DArray tile_data,
+                                    vec2 coord,
+                                    bool nearest_sampling,
+                                    bool premultiplied)
+{
+  vec2 tex_size = vec2(textureSize(tile_array, 0).xy);
+
+  vec3 uv = vec3(coord, 0);
+  if (!node_tex_tile_lookup(uv, tile_array, tile_data))
+    return vec4(1.0, 0.0, 1.0, 1.0);
+
+  /* TODO(fclem) We could do the same with sampler objects.
+   * But this is a quick workaround instead of messing with the GPUTexture itself. */
+  uv.xy = nearest_sampling ? (floor(uv.xy * tex_size) + 0.5) / tex_size : uv.xy;
+  vec4 color = texture(tile_array, uv);
+
+  /* Unpremultiply if stored multiplied, since straight alpha is expected by shaders. */
+  if (premultiplied && !(color.a == 0.0 || color.a == 1.0)) {
+    color.rgb = color.rgb / color.a;
+  }
+
+  return color;
+}