From 8b6e8943de49d728caf7791e125a7165e7b9f357 Mon Sep 17 00:00:00 2001
From: ened <acedealer2014@gmail.com>
Date: Wed, 8 Oct 2025 00:23:26 +0900
Subject: [PATCH] Fix aspect fit ratio for video

---
 .../src/Rendering/YUV420PUploadBackend.cpp    | 54 +++++++++++--------
 1 file changed, 32 insertions(+), 22 deletions(-)

diff --git a/vav2/platforms/windows/applications/vav2player/Vav2Player/src/Rendering/YUV420PUploadBackend.cpp b/vav2/platforms/windows/applications/vav2player/Vav2Player/src/Rendering/YUV420PUploadBackend.cpp
index ea14bb0..e5a56a5 100644
--- a/vav2/platforms/windows/applications/vav2player/Vav2Player/src/Rendering/YUV420PUploadBackend.cpp
+++ b/vav2/platforms/windows/applications/vav2player/Vav2Player/src/Rendering/YUV420PUploadBackend.cpp
@@ -307,22 +307,7 @@ HRESULT YUV420PUploadBackend::CreateGraphicsResources() {
 
 HRESULT YUV420PUploadBackend::CompileGraphicsShaders() {
     const char* vsSource = R"(
-struct VSOutput {
-    float4 pos : SV_POSITION;
-    float2 uv : TEXCOORD0;
-};
-
-VSOutput main(uint id : SV_VertexID) {
-    VSOutput o;
-    o.uv = float2((id << 1) & 2, id & 2);
-    o.pos = float4(o.uv * float2(2, -2) + float2(-1, 1), 0, 1);
-    return o;
-})";
-
-    const char* psSource = R"(
-Texture2D t : register(t0);
-SamplerState s : register(s0);
-cbuffer C : register(b0) {
+cbuffer AspectFitBuffer : register(b0) {
     float videoAspectRatio;
     float containerAspectRatio;
     float uvScaleX;
@@ -332,11 +317,36 @@ cbuffer C : register(b0) {
     float2 padding;
 };
 
+struct VSOutput {
+    float4 pos : SV_POSITION;
+    float2 uv : TEXCOORD0;
+};
+
+VSOutput main(uint id : SV_VertexID) {
+    VSOutput o;
+    // Generate fullscreen triangle UVs (0-1 range)
+    o.uv = float2((id << 1) & 2, id & 2);
+
+    // Apply AspectFit transformation to vertex positions
+    float2 scale = float2(uvScaleX, uvScaleY);
+    float2 offset = float2(uvOffsetX, uvOffsetY);
+
+    // Transform NDC coordinates for AspectFit
+    float2 ndcPos = o.uv * 2.0 - 1.0;  // Convert to -1 to 1
+    ndcPos *= scale;                     // Apply scale
+    ndcPos.y *= -1.0;                   // Flip Y for D3D
+
+    o.pos = float4(ndcPos, 0, 1);
+    return o;
+})";
+
+    const char* psSource = R"(
+Texture2D t : register(t0);
+SamplerState s : register(s0);
+
 float4 main(float4 pos : SV_POSITION, float2 uv : TEXCOORD0) : SV_TARGET {
-    // Apply AspectFit transformation
-    float2 transformedUV = uv * float2(uvScaleX, uvScaleY) + float2(uvOffsetX, uvOffsetY);
-    float4 color = t.Sample(s, transformedUV);
-    // RGB texture (RGBA format) to BGRA backbuffer - no swizzle needed
+    // Sample texture directly - AspectFit is handled in vertex shader
+    float4 color = t.Sample(s, uv);
     return color;
 })";
 
@@ -350,8 +360,8 @@ float4 main(float4 pos : SV_POSITION, float2 uv : TEXCOORD0) : SV_TARGET {
 HRESULT YUV420PUploadBackend::CreateGraphicsRootSignature() {
     CD3DX12_DESCRIPTOR_RANGE srvRange; srvRange.Init(D3D12_DESCRIPTOR_RANGE_TYPE_SRV, 1, 0);
     CD3DX12_ROOT_PARAMETER rootParams[2];
-    rootParams[0].InitAsDescriptorTable(1, &srvRange);
-    rootParams[1].InitAsConstantBufferView(0);
+    rootParams[0].InitAsDescriptorTable(1, &srvRange, D3D12_SHADER_VISIBILITY_PIXEL);
+    rootParams[1].InitAsConstantBufferView(0, 0, D3D12_SHADER_VISIBILITY_VERTEX);  // Bind to vertex shader
 
     D3D12_STATIC_SAMPLER_DESC samplerDesc = {};
     samplerDesc.Filter = D3D12_FILTER_MIN_MAG_MIP_LINEAR;