Merge pull request #66178 from clayjohn/double-precision-rendering

Emulate double precision for regular rendering operation when REAL_T_IS_DOUBLE

2 files changed, 17 insertions, 2 deletions

diff --git a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
index 332e511ff0..3a9c695653 100644
--- a/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
+++ b/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp
@@ -714,6 +714,14 @@ void RenderForwardClustered::_fill_instance_data(RenderListType p_render_list, i
 		instance_data.lightmap_uv_scale[2] = inst->lightmap_uv_scale.size.x;
 		instance_data.lightmap_uv_scale[3] = inst->lightmap_uv_scale.size.y;
 
+#ifdef REAL_T_IS_DOUBLE
+		// Split the origin into two components, the float approximation and the missing precision
+		// In the shader we will combine these back together to restore the lost precision.
+		RendererRD::MaterialStorage::split_double(inst->transform.origin.x, &instance_data.transform[12], &instance_data.transform[3]);
+		RendererRD::MaterialStorage::split_double(inst->transform.origin.y, &instance_data.transform[13], &instance_data.transform[7]);
+		RendererRD::MaterialStorage::split_double(inst->transform.origin.z, &instance_data.transform[14], &instance_data.transform[11]);
+#endif
+
 		bool cant_repeat = instance_data.flags & INSTANCE_DATA_FLAG_MULTIMESH || inst->mesh_instance.is_valid();
 
 		if (prev_surface != nullptr && !cant_repeat && prev_surface->sort.sort_key1 == surface->sort.sort_key1 && prev_surface->sort.sort_key2 == surface->sort.sort_key2 && repeats < RenderElementInfo::MAX_REPEATS) {
@@ -3039,6 +3047,11 @@ RenderForwardClustered::RenderForwardClustered() {
 		{
 			defines += "\n#define MATERIAL_UNIFORM_SET " + itos(MATERIAL_UNIFORM_SET) + "\n";
 		}
+#ifdef REAL_T_IS_DOUBLE
+		{
+			defines += "\n#define USE_DOUBLE_PRECISION \n";
+		}
+#endif
 
 		scene_shader.init(defines);
 	}
diff --git a/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp b/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp
index 75ccf1add5..1987577464 100644
--- a/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp
+++ b/servers/rendering/renderer_rd/forward_clustered/scene_shader_forward_clustered.cpp
@@ -621,10 +621,10 @@ void SceneShaderForwardClustered::init(const String p_defines) {
 		//shader compiler
 		ShaderCompiler::DefaultIdentifierActions actions;
 
-		actions.renames["MODEL_MATRIX"] = "model_matrix";
+		actions.renames["MODEL_MATRIX"] = "read_model_matrix";
 		actions.renames["MODEL_NORMAL_MATRIX"] = "model_normal_matrix";
 		actions.renames["VIEW_MATRIX"] = "scene_data.view_matrix";
-		actions.renames["INV_VIEW_MATRIX"] = "scene_data.inv_view_matrix";
+		actions.renames["INV_VIEW_MATRIX"] = "inv_view_matrix";
 		actions.renames["PROJECTION_MATRIX"] = "projection_matrix";
 		actions.renames["INV_PROJECTION_MATRIX"] = "inv_projection_matrix";
 		actions.renames["MODELVIEW_MATRIX"] = "modelview";
@@ -757,6 +757,8 @@ void SceneShaderForwardClustered::init(const String p_defines) {
 		actions.usage_defines["RADIANCE"] = "#define CUSTOM_RADIANCE_USED\n";
 		actions.usage_defines["IRRADIANCE"] = "#define CUSTOM_IRRADIANCE_USED\n";
 
+		actions.usage_defines["MODEL_MATRIX"] = "#define MODEL_MATRIX_USED\n";
+
 		actions.render_mode_defines["skip_vertex_transform"] = "#define SKIP_TRANSFORM_USED\n";
 		actions.render_mode_defines["world_vertex_coords"] = "#define VERTEX_WORLD_COORDS_USED\n";
 		actions.render_mode_defines["ensure_correct_normals"] = "#define ENSURE_CORRECT_NORMALS\n";