Fix #19633 by proper store to &ubo_data.shadow_matrix[1234].

It is not valid in C++ to store into shadow_matrix1[16] with shadow_matrix1[16 * j]
(for j > 0). Even though there's a valid space in a struct after shadow_matrix1.
Knowing that GCC performs aggressive optimizations that eventually lead
to a wrong code. Code has been changed into union where one can either
use shadow_matrix[4 * 16], or individual shadow_matrix1, shadow_matrix2, etc. GCC pragma
is not needed any longer.

1 files changed, 9 insertions, 4 deletions

diff --git a/drivers/gles3/rasterizer_scene_gles3.h b/drivers/gles3/rasterizer_scene_gles3.h
index 9772b5dd23..325617745a 100644
--- a/drivers/gles3/rasterizer_scene_gles3.h
+++ b/drivers/gles3/rasterizer_scene_gles3.h
@@ -569,10 +569,15 @@ public:
 		float light_params[4]; //spot attenuation, spot angle, specular, shadow enabled
 		float light_clamp[4];
 		float light_shadow_color_contact[4];
-		float shadow_matrix1[16]; //up to here for spot and omni, rest is for directional
-		float shadow_matrix2[16];
-		float shadow_matrix3[16];
-		float shadow_matrix4[16];
+		union {
+			struct {
+				float matrix1[16]; //up to here for spot and omni, rest is for directional
+				float matrix2[16];
+				float matrix3[16];
+				float matrix4[16];
+			};
+			float matrix[4 * 16];
+		} shadow;
 		float shadow_split_offsets[4];
 	};