New cpp folder structure

Signed-off-by: Alexander Borsuk <me@alex.bio>

libs/shaders/Metal/imgui.metal

@@ -0,0 +1,39 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+using namespace metal;
+
+typedef struct
+{
+  float2 a_position [[attribute(0)]];
+  float2 a_texCoords [[attribute(1)]];
+  float4 a_color [[attribute(2)]];
+} Vertex_T;
+
+typedef struct
+{
+  float4 position [[position]];
+  float2 texCoords;
+  float4 color;
+} Fragment_T;
+
+typedef struct
+{
+  float4x4 u_projection;
+} Uniforms_T;
+
+vertex Fragment_T vsImGui(const Vertex_T in [[stage_in]],
+                          constant Uniforms_T & uniforms [[buffer(1)]])
+{
+  Fragment_T out;
+  out.position = float4(in.a_position, 0.0, 1.0) * uniforms.u_projection;
+  out.texCoords = in.a_texCoords;
+  out.color = in.a_color;
+  return out;
+}
+
+fragment float4 fsImGui(const Fragment_T in [[stage_in]],
+                        texture2d<float> u_colorTex [[texture(0)]],
+                        sampler u_colorTexSampler [[sampler(0)]])
+{
+  return in.color * u_colorTex.sample(u_colorTexSampler, in.texCoords);
+}