上一次我们学习了如何画一个2D三角形，现在让我们进一步学习如何画一个旋转的彩色立方体吧。
具体流程同画三角形类似，因此不再给出完整代码了，不同的部分会再说明。
由于我们要画彩色的立方体，所以顶点结构体中加入颜色变量
struct Vertex
{
XMFLOAT3 pos;
XMFLOAT4 color;
};
着色器代码
1 cbuffer cbPerObject
2 {
3 float4x4 gWorldViewProj;
4 };
5
6 struct VertexIn
7 {
8 float3 PosL : POSITION;
9 float4 Color : COLOR;
10 };
11
12 struct VertexOut
13 {
14 float4 PosH : SV_POSITION;
15 float4 Color : COLOR;
16 };
17
18 VertexOut VS(VertexIn vin)
19 {
20 VertexOut vout;
21
22 // Transform to homogeneous clip space.
23 vout.PosH = mul(float4(vin.PosL, 1.0f), gWorldViewProj);
24
25 // Just pass vertex color into the pixel shader.
26 vout.Color = vin.Color;
27
28 return vout;
29 }
30
31 float4 PS(VertexOut pin) : SV_Target
32 {
33 return pin.Color;
34 }
35
36 technique11 ColorTech
37 {
38 pass P0
39 {
40 SetVertexShader( CompileShader( vs_5_0, VS() ) );
41 SetGeometryShader( NULL );
42 SetPixelShader( CompileShader( ps_5_0, PS() ) );
43 }
44 }
定义了一个矩阵gWorldViewProj，后面我们会利用它进行旋转立方体
BoxDemo.h
1 #pragma once
2
3 #include "Dx11DemoBase.h"
4 #include "d3dx11effect.h"
5
6 class BoxDemo : public Dx11DemoBase
7 {
8 public:
9 BoxDemo();
10 ~BoxDemo();
11
12 bool LoadContent() override;
13 void UnLoadContent() override;
14
15 void Update(float dt) override;
16 void Render() override;
17
18 private:
19 ID3D11Buffer *m_pVertexBuffer;
20 ID3D11Buffer *m_pIndexBuffer;//新增
21 ID3D11InputLayout *m_pInputLayout;
22
23 ID3DX11Effect *m_pFx;
24 ID3DX11EffectTechnique *m_pTechnique;
25 ID3DX11EffectMatrixVariable *m_pFxWorldViewProj;
26 XMFLOAT4X4 m_world;
27 XMFLOAT4X4 m_view;
28 XMFLOAT4X4 m_proj;
29
30 };
LoadContent()函数
顶点信息及缓冲的创建
1 Vertex vertices[] =
2 {
3 { XMFLOAT3(-0.5f, -0.5f, -0.5f), XMFLOAT4(255, 255, 255, 1) },//white
4 { XMFLOAT3(-0.5f, +0.5f, -0.5f), XMFLOAT4(0, 0, 0, 1) },//black
5 { XMFLOAT3(+0.5f, +0.5f, -0.5f), XMFLOAT4(255, 0, 0, 1) },//red
6 { XMFLOAT3(+0.5f, -0.5f, -0.5f), XMFLOAT4(0, 255, 0, 1) },//green
7 { XMFLOAT3(-0.5f, -0.5f, +0.5f), XMFLOAT4(0, 0, 255, 1) },//blue
8 { XMFLOAT3(-0.5f, +0.5f, +0.5f), XMFLOAT4(255, 255, 0, 1) },//yellow
9 { XMFLOAT3(+0.5f, +0.5f, +0.5f), XMFLOAT4(0, 255, 255, 1) },//cyan
10 { XMFLOAT3(+0.5f, -0.5f, +0.5f), XMFLOAT4(255, 0, 255, 1) }//magenta
11 };
12
13
14 D3D11_BUFFER_DESC vertexDesc;
15 ZeroMemory(&vertexDesc, sizeof(vertexDesc));
16 vertexDesc.Usage = D3D11_USAGE_DEFAULT;
17 vertexDesc.BindFlags = D3D11_BIND_VERTEX_BUFFER;
18 vertexDesc.ByteWidth = sizeof(Vertex)* 8;
19
20 D3D11_SUBRESOURCE_DATA resourceData;
21 ZeroMemory(&resourceData, sizeof(resourceData));
22 resourceData.pSysMem = vertices;
23 result = m_pd3dDevice->CreateBuffer(&vertexDesc, &resourceData, &m_pVertexBuffer);
24 if (FAILED(result))
25 {
26 return false;
27 }
相比三角形，立方体还要定义Index信息，来确定立方体的六个面
1 UINT indices[] = {
2 // front face
3 0, 1, 2,
4 0, 2, 3,
5
6 // back face
7 4, 6, 5,
8 4, 7, 6,
9
10 // left face
11 4, 5, 1,
12 4, 1, 0,
13
14 // right face
15 3, 2, 6,
16 3, 6, 7,
17
18 // top face
19 1, 5, 6,
20 1, 6, 2,
21
22 // bottom face
23 4, 0, 3,
24 4, 3, 7
25 };
26
27 D3D11_BUFFER_DESC indexDesc;
28 ZeroMemory(&indexDesc, sizeof(indexDesc));
29 indexDesc.Usage = D3D11_USAGE_IMMUTABLE;
30 indexDesc.BindFlags = D3D11_BIND_INDEX_BUFFER;
31 indexDesc.ByteWidth = sizeof(UINT)* 36;
32
33 D3D11_SUBRESOURCE_DATA indexData;
34 ZeroMemory(&indexData, sizeof(indexData));
35 indexData.pSysMem = indices;
36 result = m_pd3dDevice->CreateBuffer(&indexDesc, &indexData, &m_pIndexBuffer);
37 if (FAILED(result))
38 {
39 return false;
40 }
定义输入布局
1 D3D11_INPUT_ELEMENT_DESC solidColorLayout[] =
2 {
3 { "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
4 { "COLOR", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 }
5 };
6 UINT numLayoutElements = ARRAYSIZE(solidColorLayout);
7 D3DX11_PASS_DESC passDesc;
8 m_pTechnique->GetPassByIndex(0)->GetDesc(&passDesc);
9
10 result = m_pd3dDevice->CreateInputLayout(solidColorLayout, numLayoutElements, passDesc.pIAInputSignature,
11 passDesc.IAInputSignatureSize, &m_pInputLayout);
Update()函数----实现旋转
怎么实现立方体的旋转呢？我们之前不是给出了 world,view,proj三个矩阵吗，实现旋转的一种方式就是根据游戏时间旋转相应矩阵(例如world矩阵)。
可以定义一个静态变量表示游戏时间，每一帧运行时更新t值，同时对矩阵作相应旋转即可。
1 static float t = 0.0f; 2 t += (float)XM_PI * 0.0125f; 3 static DWORD dwTimeStart = 0; 4 DWORD dwTimeCur = GetTickCount(); 5 if (dwTimeStart == 0) 6 dwTimeStart = dwTimeCur; 7 t = (dwTimeCur - dwTimeStart) / 1000.0f; 8 9 XMVECTOR pos = XMVectorSet(2.0f, 0.0f, 0.0f, 1.0f); 10 XMVECTOR target = XMVectorSet(0.0f, 0.0f, 0.0f, 1.0f); 11 XMVECTOR up = XMVectorSet(0.0f, 1.0f, 0.0f, 0.0f); 12 13 XMMATRIX V = XMMatrixLookAtLH(pos, target, up); 14 XMStoreFloat4x4(&m_view, V); 15 XMMATRIX T = XMMatrixPerspectiveFovLH(XM_PIDIV2, m_width / static_cast<float>(m_height), 16 0.01f, 100.0f); 17 XMStoreFloat4x4(&m_proj, T); 18 //根据时间旋转world矩阵 19 XMMATRIX P = XMMatrixRotationY(t); 20 XMStoreFloat4x4(&m_world, P);
Render()函数
和之前的代码大部分一样，不同的是要设置IndexBuffer，绘制的时候要用DrawIndexed()而不是Draw().
1 if (m_pImmediateContext == 0)
2 return;
3 //清除渲染目标视图
4 float clearColor[4] = { 1.0f, 1.0f, 1.0f, 1.0f };//背景颜色
5 m_pImmediateContext->ClearRenderTargetView(m_pRenderTargetView, clearColor);
6
7 UINT stride = sizeof(Vertex);
8 UINT offset = 0;
9 //设置数据信息格式控制信息
10 m_pImmediateContext->IASetInputLayout(m_pInputLayout);
11 //设置要绘制的几何体信息
12 m_pImmediateContext->IASetVertexBuffers(0,1,&m_pVertexBuffer,&stride,&offset);
13 m_pImmediateContext->IASetIndexBuffer(m_pIndexBuffer, DXGI_FORMAT_R32_UINT, 0);
14 //指明如何绘制
15 m_pImmediateContext->IASetPrimitiveTopology(D3D11_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
16
17 //设置常量
18 XMMATRIX world = XMLoadFloat4x4(&m_world);
19 XMMATRIX view = XMLoadFloat4x4(&m_view);
20 XMMATRIX proj = XMLoadFloat4x4(&m_proj);
21 XMMATRIX worldViewProj = world*view*proj;
22 m_pFxWorldViewProj->SetMatrix(reinterpret_cast<float*>(&worldViewProj));
23
24 D3DX11_TECHNIQUE_DESC techDesc;
25 m_pTechnique->GetDesc(&techDesc);
26 for (UINT i = 0; i < techDesc.Passes; ++i)
27 {
28 m_pTechnique->GetPassByIndex(i)->Apply(0, m_pImmediateContext);
29 m_pImmediateContext->DrawIndexed(36, 0, 0);
30 }
31 //马上输出
32 m_pSwapChain->Present(0, 0);
这样我们的工作都完成了，运行便可以得到一个旋转的彩色立方体了.
下面是运行的一个截图
时间： 2024-08-07 06:38:28