fix: D3D12 sphere rendering - correct matrix math, enable depth test, add texture sampling

- Fix TranslationMatrix to use correct indices (m12/m13/m14 for translation)
- Fix PerspectiveMatrix projection formula
- Enable depth testing (was disabled)
- Add texture sampling in pixel shader
- Adjust sphere radius to 1.0 and position to z=5
- Fix D3D12Buffer copy size calculation

engine/src/RHI/D3D12/D3D12Buffer.cpp

@@ -99,7 +99,7 @@ bool D3D12Buffer::InitializeWithData(ID3D12Device* device, ID3D12GraphicsCommand
     D3D12_RESOURCE_DESC d3d12TempResourceDesc = {};
     d3d12TempResourceDesc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
     d3d12TempResourceDesc.Alignment = 0;
-    d3d12TempResourceDesc.Width = memorySizeUsed;
+    d3d12TempResourceDesc.Width = size;
     d3d12TempResourceDesc.Height = 1;
     d3d12TempResourceDesc.DepthOrArraySize = 1;
     d3d12TempResourceDesc.MipLevels = 1;
@@ -129,7 +129,7 @@ bool D3D12Buffer::InitializeWithData(ID3D12Device* device, ID3D12GraphicsCommand
     memcpy(pDstTempBuffer, pSrcData, size);
     tempBufferObject->Unmap(0, nullptr);
 
-    commandList->CopyBufferRegion(m_resource.Get(), 0, tempBufferObject, 0, subresourceFootprint.Footprint.Width);
+    commandList->CopyBufferRegion(m_resource.Get(), 0, tempBufferObject, 0, size);
 
     D3D12_RESOURCE_BARRIER barrier = {};
     barrier.Type = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;

tests/RHI/D3D12/integration/sphere/Res/Shader/sphere.hlsl

@@ -8,17 +8,25 @@ struct VSOut {
     float4 texcoord : TEXCOORD0;
 };
 
+Texture2D gDiffuseTexture : register(t0);
+SamplerState gSampler : register(s0);
+
 cbuffer MatrixBuffer : register(b0) {
-    float4x4 gMVP;
+    float4x4 gProjectionMatrix;
+    float4x4 gViewMatrix;
+    float4x4 gModelMatrix;
+    float4x4 gIT_ModelMatrix;
 };
 
 VSOut MainVS(Vertex v) {
     VSOut o;
-    o.pos = mul(gMVP, v.pos);
+    float4 positionWS = mul(gModelMatrix, v.pos);
+    float4 positionVS = mul(gViewMatrix, positionWS);
+    o.pos = mul(gProjectionMatrix, positionVS);
     o.texcoord = v.texcoord;
     return o;
 }
 
 float4 MainPS(VSOut i) : SV_TARGET {
-    return float4(1.0f, 0.0f, 0.0f, 1.0f);
+    return gDiffuseTexture.Sample(gSampler, i.texcoord.xy);
 }

tests/RHI/D3D12/integration/sphere/main.cpp

@@ -73,9 +73,6 @@ UINT gIndexCount = 0;
 float gProjectionMatrix[16];
 float gViewMatrix[16];
 float gModelMatrix[16];
-float gMVPMatrix[16];
-float gTempMatrix[16];
-float gTransposedMatrix[16];
 
 HWND gHWND = nullptr;
 int gWidth = 1280;
@@ -104,14 +101,23 @@ void IdentityMatrix(float* m) {
     m[0] = m[5] = m[10] = m[15] = 1.0f;
 }
 
+void TranslationMatrix(float* m, float x, float y, float z) {
+    memset(m, 0, 16 * sizeof(float));
+    m[0] = 1.0f; m[12] = x;
+    m[5] = 1.0f; m[13] = y;
+    m[10] = 1.0f; m[14] = z;
+    m[15] = 1.0f;
+}
+
 void PerspectiveMatrix(float* m, float fov, float aspect, float nearZ, float farZ) {
     memset(m, 0, 16 * sizeof(float));
     float tanHalfFov = tanf(fov / 2.0f);
     m[0] = 1.0f / (aspect * tanHalfFov);
     m[5] = 1.0f / tanHalfFov;
-    m[10] = (farZ + nearZ) / (nearZ - farZ);
+    m[10] = farZ / (farZ - nearZ);
-    m[11] = -1.0f;
+    m[11] = 1.0f;
-    m[14] = (2.0f * farZ * nearZ) / (nearZ - farZ);
+    m[14] = -(farZ * nearZ) / (farZ - nearZ);
+    m[15] = 0.0f;
 }
 
 void LookAtMatrix(float* m, const float* eye, const float* target, const float* up) {
@@ -360,7 +366,7 @@ bool InitD3D12() {
     psoDesc.RasterizerState.CullMode = D3D12_CULL_MODE_NONE;
     psoDesc.RasterizerState.FrontCounterClockwise = FALSE;
     psoDesc.RasterizerState.DepthClipEnable = TRUE;
-    psoDesc.DepthStencilState.DepthEnable = FALSE;
+    psoDesc.DepthStencilState.DepthEnable = TRUE;
     psoDesc.DepthStencilState.DepthWriteMask = D3D12_DEPTH_WRITE_MASK_ZERO;
     psoDesc.DepthStencilState.DepthFunc = D3D12_COMPARISON_FUNC_LESS;
     psoDesc.BlendState.RenderTarget[0].BlendEnable = FALSE;
@@ -396,19 +402,18 @@ bool InitD3D12() {
     }
     gIndexBuffer.SetBufferType(BufferType::Index);
 
-    PerspectiveMatrix(gProjectionMatrix, 45.0f * 3.14159f / 180.0f, (float)gWidth / (float)gHeight, 0.1f, 100.0f);
+    float aspect = 1280.0f / 720.0f;
+    PerspectiveMatrix(gProjectionMatrix, 45.0f * 3.141592f / 180.0f, aspect, 0.1f, 1000.0f);
+    IdentityMatrix(gViewMatrix);
+    TranslationMatrix(gModelMatrix, 0.0f, 0.0f, 5.0f);
 
-    float eye[3] = { 0.0f, 0.0f, 3.0f };
+    float matrices[64];
-    float target[3] = { 0.0f, 0.0f, 0.0f };
+    memcpy(matrices, gProjectionMatrix, 64);
-    float up[3] = { 0.0f, 1.0f, 0.0f };
+    memcpy(matrices + 16, gViewMatrix, 64);
-    LookAtMatrix(gViewMatrix, eye, target, up);
+    memcpy(matrices + 32, gModelMatrix, 64);
+    memcpy(matrices + 48, gModelMatrix, 64);
 
-    IdentityMatrix(gModelMatrix);
+    gMVPBuffer.InitializeWithData(device, gCommandList.GetCommandList(), matrices, sizeof(matrices), D3D12_RESOURCE_STATE_VERTEX_AND_CONSTANT_BUFFER);
-    MultiplyMatrix(gTempMatrix, gViewMatrix, gModelMatrix);
-    MultiplyMatrix(gMVPMatrix, gProjectionMatrix, gTempMatrix);
-    TransposeMatrix(gTransposedMatrix, gMVPMatrix);
-
-    gMVPBuffer.InitializeWithData(device, gCommandList.GetCommandList(), gTransposedMatrix, sizeof(gTransposedMatrix), D3D12_RESOURCE_STATE_VERTEX_AND_CONSTANT_BUFFER);
 
     if (!LoadTexture("Res/Image/earth.png", gDiffuseTexture, gDiffuseSRV, device, gSRVHeap, gCommandList.GetCommandList(), gCommandAllocator, gCommandQueue)) {
         Log("[ERROR] Failed to load texture");