Merge pull request #56161 from The-O-King/blend_shapes_octahedral

drivers/gles3/rasterizer_scene_gles3.cpp

@@ -1268,6 +1268,8 @@ void RasterizerSceneGLES3::_setup_geometry(RenderList::Element *e, const Transfo
 			if (s->blend_shapes.size() && e->instance->blend_values.size()) {
 				//blend shapes, use transform feedback
 				storage->mesh_render_blend_shapes(s, e->instance->blend_values.read().ptr());
+				//disable octahedral compression as the result of blend shapes is always uncompressed cartesian coordinates
+				state.scene_shader.set_conditional(SceneShaderGLES3::ENABLE_OCTAHEDRAL_COMPRESSION, false);
 				//rebind shader
 				state.scene_shader.bind();
 #ifdef DEBUG_ENABLED

drivers/gles3/rasterizer_storage_gles3.cpp

@@ -4300,6 +4300,7 @@ void RasterizerStorageGLES3::mesh_render_blend_shapes(Surface *s, const float *p
 
 	shaders.blend_shapes.set_conditional(BlendShapeShaderGLES3::ENABLE_BLEND, false); //first pass does not blend
 	shaders.blend_shapes.set_conditional(BlendShapeShaderGLES3::USE_2D_VERTEX, s->format & VS::ARRAY_FLAG_USE_2D_VERTICES); //use 2D vertices if needed
+	shaders.blend_shapes.set_conditional(BlendShapeShaderGLES3::ENABLE_OCTAHEDRAL_COMPRESSION, s->format & VS::ARRAY_FLAG_USE_OCTAHEDRAL_COMPRESSION); //use octahedral normal compression
 
 	shaders.blend_shapes.bind();
 

drivers/gles3/shaders/blend_shape.glsl

@@ -25,11 +25,19 @@ ARRAY_INDEX=8,
 
 layout(location = 0) in highp VFORMAT vertex_attrib;
 /* clang-format on */
+#ifdef ENABLE_OCTAHEDRAL_COMPRESSION
+layout(location = 2) in vec4 normal_tangent_attrib;
+#else
 layout(location = 1) in vec3 normal_attrib;
+#endif
 
 #ifdef ENABLE_TANGENT
+#ifdef ENABLE_OCTAHEDRAL_COMPRESSION
+// packed into normal_attrib zw component
+#else
 layout(location = 2) in vec4 tangent_attrib;
 #endif
+#endif
 
 #ifdef ENABLE_COLOR
 layout(location = 3) in vec4 color_attrib;
@@ -109,20 +117,37 @@ out vec4 weight_out; //tfb:ENABLE_SKELETON
 
 uniform float blend_amount;
 
+#ifdef ENABLE_OCTAHEDRAL_COMPRESSION
+vec3 oct_to_vec3(vec2 e) {
+	vec3 v = vec3(e.xy, 1.0 - abs(e.x) - abs(e.y));
+	float t = max(-v.z, 0.0);
+	v.xy += t * -sign(v.xy);
+	return normalize(v);
+}
+#endif
+
 void main() {
 #ifdef ENABLE_BLEND
 
 	vertex_out = vertex_attrib_blend + vertex_attrib * blend_amount;
 
 #ifdef ENABLE_NORMAL
+#ifdef ENABLE_OCTAHEDRAL_COMPRESSION
+	normal_out = normal_attrib_blend + oct_to_vec3(normal_tangent_attrib.xy) * blend_amount;
+#else
 	normal_out = normal_attrib_blend + normal_attrib * blend_amount;
 #endif
+#endif
 
 #ifdef ENABLE_TANGENT
-
+#ifdef ENABLE_OCTAHEDRAL_COMPRESSION
+	tangent_out.xyz = tangent_attrib_blend.xyz + oct_to_vec3(vec2(normal_tangent_attrib.z, abs(normal_tangent_attrib.w) * 2.0 - 1.0)) * blend_amount;
+	tangent_out.w = sign(tangent_attrib_blend.w);
+#else
 	tangent_out.xyz = tangent_attrib_blend.xyz + tangent_attrib.xyz * blend_amount;
 	tangent_out.w = tangent_attrib_blend.w; //just copy, no point in blending his
 #endif
+#endif
 
 #ifdef ENABLE_COLOR
 
@@ -150,14 +175,22 @@ void main() {
 	vertex_out = vertex_attrib * blend_amount;
 
 #ifdef ENABLE_NORMAL
+#ifdef ENABLE_OCTAHEDRAL_COMPRESSION
+	normal_out = oct_to_vec3(normal_tangent_attrib.xy) * blend_amount;
+#else
 	normal_out = normal_attrib * blend_amount;
 #endif
+#endif
 
 #ifdef ENABLE_TANGENT
-
+#ifdef ENABLE_OCTAHEDRAL_COMPRESSION
+	tangent_out.xyz = oct_to_vec3(vec2(normal_tangent_attrib.z, abs(normal_tangent_attrib.w) * 2.0 - 1.0)) * blend_amount;
+	tangent_out.w = sign(normal_tangent_attrib.w);
+#else
 	tangent_out.xyz = tangent_attrib.xyz * blend_amount;
 	tangent_out.w = tangent_attrib.w; //just copy, no point in blending his
 #endif
+#endif
 
 #ifdef ENABLE_COLOR