记录下来自己下次又愚蠢了的时候看看
目的：创建纹理，修改问题数据--渲染输出
问题：修改纹理数据不成功！
原因：创建纹理时使用的格式不对DXGI_FORMAT_R8G8B8A8_UNORM----DXGI_FORMAT_R32_UINT;
创建纹理描述代码：
D3D11_TEXTURE2D_DESC textureDesc;
// Initialize the texture description.
ZeroMemory(&textureDesc, sizeof(textureDesc));
// Setup the texture description.
// We will have our map be a square
// We will need to have this texture bound as a render target AND a shader resource
textureDesc.Width = m_nWidth;
textureDesc.Height = m_nHeight;
textureDesc.MipLevels = 1;
textureDesc.ArraySize = 1;
textureDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;//原本使用DXGI_FORMAT_R32_UINT格式，一直不成功
textureDesc.SampleDesc.Count = 1;
textureDesc.Usage = D3D11_USAGE_DYNAMIC;//D3D11_USAGE_DEFAULT;
textureDesc.BindFlags = D3D11_BIND_SHADER_RESOURCE;///< D3D11_BIND_RENDER_TARGET |
textureDesc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
textureDesc.MiscFlags = 0;
修改纹理数据代码：
HRESULT hr = S_OK;
D3D11_MAPPED_SUBRESOURCE MappedResource;
hr = m_pImmediateContext->Map(m_pBlendTexture,0, D3D11_MAP_WRITE_DISCARD, 0, &MappedResource);
if(FAILED(hr)) return false;
BYTE* pRow = (BYTE*)MappedResource.pData;
for (int j=0; j<m_nHeight; j++)
{
int nOffset=0;
for (int i=0; i<m_nWidth; i++)
{
const BYTE pbyte = (BYTE)255;
memcpy(pRow+nOffset+1, &pbyte, sizeof(BYTE));
nOffset+=4;
}
pRow += MappedResource.RowPitch;
}
m_pImmediateContext->Unmap(m_pBlendTexture, 0);
return hr;
MSDN描述：
DXGI_FORMAT_R8G8B8A8_UNORM
DXGI_FORMAT_R8G8B8A8_UINT
A four-component, 32-bit unsigned-integer format.
咋一看，两个都一样，不过还有下文当初我没看到
| _UINT | Unsigned integer. For instance, a 3-bit UINT represents the values 0, 1, 2, 3, 4, 5, 6, 7. |
| _UNORM | Unsigned normalized integer; which is interpreted in a resource as an unsigned integer, and is interpreted in a shader as an unsigned normalized floating-point value in the range [0, 1]. All 0's maps to 0.0f, and all 1's maps to 1.0f. A sequence of evenly spaced floating-point values from 0.0f to 1.0f are represented. For instance, a 2-bit UNORM represents 0.0f, 1/3, 2/3, and 1.0f. |
带_UINT后缀的为无符号整形，如3位无符号可以表示的值有：000-->0, 001-->1, ......111-->7;
而带_UNORM后缀的无符号整形，代表的是归一化的，如2位无符号可以表示的数：00-->0.0f, 01-->1/3.0f, 10-->2/3.0f, 11-->3/3.0f==1.0f;
下面的来自：http://www.gamedev.net/topic/546150-dxgi_format_r8g8b8a8_unorm-vs-uint/
modus Members - Reputation: 148
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Posted 01 September 2009 - 10:56 AM
I think the only formats currently supported for display are
- R8G8B8A8_UNORM
- R8G8B8A8_UNORM_SRGB
- R10G10B10A2_UNORM
- R16G16B16A16_FLOAT
You can call CheckFormatSupport with D3D10_FORMAT_SUPPORT_DISPLAY on your device for a given format.