add DirectXMath

StudyDx/App.cpp

@@ -25,6 +25,10 @@ void App::DoFrame()
 {
 	const float c = sin(timer.Peek()) / 2.0f + 0.5f;
 	wnd.Gfx().ClearBuffer(c, c, 1.0f);
-	wnd.Gfx().DrawTestTriangle( timer.Peek() );
+	wnd.Gfx().DrawTestTriangle(
+		timer.Peek(),
+		wnd.mouse.GetPosX() / 400.0f - 1.0f,
+		- wnd.mouse.GetPosY() / 300.0f + 1.0f
+	);
 	wnd.Gfx().EndFrame();
 }
\ No newline at end of file

StudyDx/Graphics.cpp

@@ -2,6 +2,9 @@
 #include "dxerr.h"
 #include <sstream>
 #include <d3dcompiler.h>
+#include <DirectXMath.h>
+
+namespace dx = DirectX;
 
 namespace wrl = Microsoft::WRL;
 
@@ -102,7 +105,7 @@ void Graphics::ClearBuffer(float red, float green, float blue) noexcept
 	pContext->ClearRenderTargetView(pTarget.Get(), color);
 }
 
-void Graphics::DrawTestTriangle(float angle)
+void Graphics::DrawTestTriangle(float angle, float x, float y)
 {
 	namespace wrl = Microsoft::WRL;
 	HRESULT hr;
@@ -179,21 +182,23 @@ void Graphics::DrawTestTriangle(float angle)
 	// Create constant buffer for transformation matrix
 	struct ConstantBuffer
 	{
-		struct
-		{
-			float element[4][4];
-		} transformation;
+		// Use extended mathematics matrix which is optmized for SIMD
+		// SIMD (Single Instruction Multiple Data) is available in mordern processors
+		dx::XMMATRIX transform;
 	};
 
 	const float heightWidthRatio = 0.3f / 0.4f;
 	const ConstantBuffer cb =
 	{
-		{
-			heightWidthRatio * std::cos(angle),		-std::sin(angle),	0.0f,	0.0f,
-			heightWidthRatio * std::sin(angle),		std::cos(angle),	0.0f,	0.0f,
-			0.0f,									0.0f,				1.0f,	0.0f,
-			0.0f,									0.0f,				0.0f,	1.0f,
-		}
+		// transpose the matrix to change from row_major to column_major
+		dx::XMMatrixTranspose(
+			// rotate Z axis
+			dx::XMMatrixRotationZ(-angle)
+			// scale to avoid distortion
+			* dx::XMMatrixScaling(3.0f / 4.0f, 1.0f, 1.0f)
+			// attach the image to mouse
+			* dx::XMMatrixTranslation( x, y, 0.0f )
+		)
 	};
 	wrl::ComPtr<ID3D11Buffer> pConstantBuffer;
 	D3D11_BUFFER_DESC cbd = {};

StudyDx/Graphics.h

@@ -53,7 +53,7 @@ public:
 	void EndFrame();
 	// 刷新RGB
 	void ClearBuffer(float red, float green, float blue) noexcept;
-    void DrawTestTriangle(float angle);
+    void DrawTestTriangle(float angle, float x, float y);
 private:
     #ifndef NDEBUG
     DxgiInfoManager infoManager;

StudyDx/VertexShader.hlsl

@@ -6,7 +6,7 @@ struct VSOut
 
 cbuffer CBuf
 {
-	row_major matrix transform;
+	matrix transform;
 };
 
 VSOut main( float2 pos : Position, float3 color : Color )