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External Texture Image

How to use EGLKHRExternalTexture

To use an DMA buffer as an external texture create an array to hold necessary information. This varies with platforms and types of buffers. This example shows using DMS buffers on RCarH3.

//Activate appropriate RenderTarget first.

EGLint defaultAttribs[13];
defaultAttribs[0] = EGL_DMA_BUF_PLANE0_FD_EXT;
defaultAttribs[1] = <file descriptor of the buffer>;  //file descriptor 
defaultAttribs[2] = EGL_DMA_BUF_PLANE0_OFFSET_EXT;
defaultAttribs[3] = 0; // depends on platform and requirements
defaultAttribs[4] = EGL_DMA_BUF_PLANE0_PITCH_EXT;
defaultAttribs[5] = <pitch of the buffer>; 
defaultAttribs[6] = EGL_LINUX_DRM_FOURCC_EXT; 
defaultAttribs[7] = DRM_FORMAT_ARGB8888;  // depends on platform and requirements
defaultAttribs[8] = EGL_WIDTH;
defaultAttribs[9] = 255; // width of the image. Also set this to the EglKhrExternalTextureImage 
defaultAttribs[10] = EGL_HEIGHT;
defaultAttribs[11] = 456; // height of the image. Also set this to the EglKhrExternalTextureImage 
defaultAttribs[12] = EGL_NONE; //Terminator
Candera::EglKhrExternalTextureImage::SharedPointer ptr = Candera::EglKhrExternalTextureImage::Create();
ptr->SetRole(<Candera::EglKhrExternalTextureImage::Consumer| Candera::EglKhrExternalTextureImage::Producer>); //Can only be set once on purpose! Use producer to render to this buffer and consumer if it shall be used as texture.
ptr->SetAttributeList(defaultAttribs);  // will be deep copied. 
ptr->SetExternalBufferType(EGL_LINUX_DMA_BUF_EXT); // buffer type
ptr->SetExternalBuffer(static_cast<EGLClientBuffer>(0)); // actual buffer 
ptr->SetWidth(255); 
ptr->SetHeight(456);
ptr->Upload();

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