[feat]: complete RHI api

1 files changed, 39 insertions, 0 deletions

diff --git a/assets/shaders/grid.slang b/assets/shaders/grid.slang
new file mode 100644
index 0000000..f549cb1
--- /dev/null
+++ b/assets/shaders/grid.slang
@@ -0,0 +1,39 @@
+// Reference grid on the XZ plane. Uniforms live in a ConstantBuffer (UBO) so both
+// backends drive it through the same RHI path (bind a uniform buffer at binding 0).
+struct GridU
+{
+    float4x4 u_ViewProjection;
+    float4x4 u_Transform;
+    float    u_GridSize;
+    float3   u_GridColor;
+    float    u_GridAlpha;
+    float3   u_CameraPos;
+};
+ConstantBuffer<GridU> gu;
+
+struct VSInput  { float3 position : POSITION; };
+struct VSOutput { float4 position : SV_Position; };
+
+[shader("vertex")]
+VSOutput vertexMain(VSInput input)
+{
+    VSOutput output;
+    float3 scaledPosition = input.position * (gu.u_GridSize / 50.0);
+    output.position = mul(gu.u_ViewProjection, mul(gu.u_Transform, float4(scaledPosition, 1.0)));
+    return output;
+}
+
+[shader("fragment")]
+float4 fragmentMain(VSOutput input) : SV_Target
+{
+    float dist       = length(gu.u_CameraPos);
+    float fadeFactor = 1.0 - clamp(dist / 100.0, 0.0, 0.8);
+
+    float3 color = gu.u_GridColor;
+    float  alpha = gu.u_GridAlpha * fadeFactor;
+
+    float gridFade = 1.0 - clamp(dist / 50.0, 0.0, 0.9);
+    alpha *= gridFade;
+
+    return float4(color, alpha);
+}