brought back functionality from previous builds but now cross-platform

funnyassets/gfx_shaders/mesh_shared.slang

@@ -1,4 +1,5 @@
 #pragma once
+#include "shader_base.h"
 
 struct VertexOutput
 {
@@ -6,10 +7,17 @@ struct VertexOutput
 	float2 uv: TEXCOORD0;
 };
 
-struct PushConstants
+DECLARE_CONSTANTS()
 {
 	float4x4 modelMatrix;
 	uint albedoID;
 	uint roughnessID;
 	uint metalnessID;
 };
+
+DECLARE_CBUFFER(0)
+{
+	float4x4 projection;
+};
+
+DECLARE_TEXTURES(1)