DRW-Next: Add uniform attributes (object attributes) support

This replaces the direct shader uniform layout declaration by a linear
search through a global buffer.

Each instance has an attribute offset inside the global buffer and an
attribute count.

This removes any padding and tighly pack all uniform attributes inside
a single buffer.

This would also remove the limit of 8 attribute but it is kept because of
compatibility with the old system that is still used by the old draw
manager.

1 files changed, 7 insertions, 0 deletions

diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_attribute.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_attribute.glsl
index af4a511d627..bacf089deb1 100644
--- a/source/blender/gpu/shaders/material/gpu_shader_material_attribute.glsl
+++ b/source/blender/gpu/shaders/material/gpu_shader_material_attribute.glsl
@@ -22,6 +22,13 @@ void node_attribute_flame(vec4 attr, out float out_attr)
   out_attr = attr.x;
 }
 
+void node_attribute_uniform(vec4 attr, const float attr_hash, out vec4 out_attr)
+{
+  /* Temporary solution to support both old UBO attribs and new SSBO loading.
+   * Old UBO load is already done through `attr` and will just be passed through. */
+  out_attr = attr_load_uniform(attr, floatBitsToUint(attr_hash));
+}
+
 void node_attribute(
     vec4 attr, out vec4 outcol, out vec3 outvec, out float outf, out float outalpha)
 {