SlimDX (DirectX10) - How to change a texel in Texture? - directx

Question

I try to change the texels of a Texture which is already loaded.
My assumption was to use the Texture2D::Map and UnMap functions, but there is no change when I change the data of given DataRectangle.
I need a simple example like, creating a texture of 128x128 with a gradient from black to white from each side.
Thx
ps: A Direct3D 10 C++ example may also help, SlimDX is only a wrapper and has nearly complete the same functions.

Answer 1

This is my D3D10 2D texture loader
bool D3D10Texture::Init( GFXHandler* pHandler, unsigned int usage, unsigned int width, unsigned int height, unsigned int textureType, bool bMipmapped, void* pTextureData )
{
mMipmapped = bMipmapped;
//SetData( pHandler, 0 );
D3D10Handler* pD3DHandler = (D3D10Handler*)pHandler;
ID3D10Device* pDevice = pD3DHandler->GetDevice();
DXGI_SAMPLE_DESC dxgiSampleDesc;
dxgiSampleDesc.Count = 1;
dxgiSampleDesc.Quality = 0;
D3D10_USAGE d3d10Usage;
if ( usage & RU_All_Dynamic ) d3d10Usage = D3D10_USAGE_DYNAMIC;
else d3d10Usage = D3D10_USAGE_DEFAULT;
//unsigned int cpuAccess = D3D10_CPU_ACCESS_WRITE;
//if ( (usage & RU_Buffer_WriteOnly) == 0 ) cpuAccess |= D3D10_CPU_ACCESS_READ;
unsigned int cpuAccess = 0;
if ( !pTextureData )
{
cpuAccess = D3D10_CPU_ACCESS_WRITE;
//if ( (usage & RU_Buffer_WriteOnly) == 0 ) cpuAccess |= D3D10_CPU_ACCESS_READ;
}
unsigned int bindFlags = D3D10_BIND_SHADER_RESOURCE;
if ( usage & RU_Texture_RenderTarget ) bindFlags |= D3D10_BIND_RENDER_TARGET;
unsigned int miscFlags = 0;
if ( usage & RU_Texture_AutoGenMipmap ) miscFlags |= D3D10_RESOURCE_MISC_GENERATE_MIPS;
D3D10_TEXTURE2D_DESC d3d10Texture2DDesc;
d3d10Texture2DDesc.Width = width;
d3d10Texture2DDesc.Height = height;
d3d10Texture2DDesc.MipLevels = GetNumMipMaps( width, height, bMipmapped );
d3d10Texture2DDesc.ArraySize = 1;
d3d10Texture2DDesc.Format = GetD3DFormat( (TextureTypes)textureType );
d3d10Texture2DDesc.SampleDesc = dxgiSampleDesc;
d3d10Texture2DDesc.Usage = d3d10Usage;
d3d10Texture2DDesc.BindFlags = D3D10_BIND_SHADER_RESOURCE;
d3d10Texture2DDesc.CPUAccessFlags = cpuAccess;
d3d10Texture2DDesc.MiscFlags = miscFlags;
//D3D10_SUBRESOURCE_DATA d3d10SubResourceData;
//d3d10SubResourceData.pSysMem = pTextureData;
//d3d10SubResourceData.SysMemPitch = GetPitch( width, (TextureTypes)textureType );
//d3d10SubResourceData.SysMemSlicePitch = 0;
D3D10_SUBRESOURCE_DATA* pSubResourceData = NULL;
if ( pTextureData )
{
pSubResourceData = new D3D10_SUBRESOURCE_DATA[d3d10Texture2DDesc.MipLevels];
char* pTexPos = (char*)pTextureData;
unsigned int pitch = GetPitch( width, (TextureTypes)textureType );
unsigned int count = 0;
unsigned int max = d3d10Texture2DDesc.MipLevels;
while( count < max )
{
pSubResourceData[count].pSysMem = pTexPos;
pSubResourceData[count].SysMemPitch = pitch;
pSubResourceData[count].SysMemSlicePitch = 0;
pTexPos += pitch * height;
pitch >>= 1;
count++;
}
}
if ( FAILED( pDevice->CreateTexture2D( &d3d10Texture2DDesc, pSubResourceData, &mpTexture ) ) )
{
return false;
}
if ( pSubResourceData )
{
delete[] pSubResourceData;
pSubResourceData = NULL;
}
mWidth = width;
mHeight = height;
mFormat = (TextureTypes)textureType;
mpTexture->AddRef();
mpTexture->Release();
D3D10_SHADER_RESOURCE_VIEW_DESC d3d10ShaderResourceViewDesc;
d3d10ShaderResourceViewDesc.Format = d3d10Texture2DDesc.Format;
d3d10ShaderResourceViewDesc.ViewDimension = D3D10_SRV_DIMENSION_TEXTURE2D;
d3d10ShaderResourceViewDesc.Texture2D.MostDetailedMip = 0;
d3d10ShaderResourceViewDesc.Texture2D.MipLevels = GetNumMipMaps( width, height, bMipmapped );
if ( FAILED( pDevice->CreateShaderResourceView( mpTexture, &d3d10ShaderResourceViewDesc, &mpView ) ) )
{
return false;
}
ResourceRecorder::Instance()->AddResource( this );
return true;
}
With that function all you need to do is pass in the whit to black texture. For example to write a 256x256 textue with each horizontal line being one brighter than the previous line the following code will work
int* pTexture = new int[256 * 256];
int count = 0;
while( count < 256 )
{
int count2 = 0;
while( count2 < 256 )
{
pTexture[(count * 256) + count2] = 0xff000000 | (count << 16) | (count << 8) | count;
count2++;
}
count++;
}

Answer 2

Make sure you follow the rules in the "Resource Usage Restrictions" section:
MSDN: D3D10_USAGE

Answer 3

public void NewData(byte[] newData)
{
DataRectangle mappedTex = null;
//assign and lock the resource
mappedTex = pTexture.Map(0, D3D10.MapMode.WriteDiscard, D3D10.MapFlags.None);
// if unable to hold texture
if (!mappedTex.Data.CanWrite)
{
throw new ApplicationException("Cannot Write to the Texture");
}
// write new data to the texture
mappedTex.Data.WriteRange<byte>(newData);
// unlock the resource
pTexture.Unmap(0);
if (samplerflag)
temptex = newData;
}
this overwrites the buffer on every new frame, you may want to use a D3D10.MapMode.readwrite or something if ur only trying to write one texel
you will also need to write to the datarectangle in a specific point using one of the other write functions