Method copyCameraImageData

examples/ExampleBrowser/OpenGLGuiHelper.cpp:1257–1438

}

void OpenGLGuiHelper::copyCameraImageData(const float viewMatrix[16], const float projectionMatrix[16],
										  unsigned char* pixelsRGBA, int rgbaBufferSizeInPixels,
										  float* depthBuffer, int depthBufferSizeInPixels,
										  int* segmentationMaskBuffer, int segmentationMaskBufferSizeInPixels,
										  int startPixelIndex, int destinationWidth,
										  int destinationHeight, int* numPixelsCopied)
{
	int sourceWidth = btMin(destinationWidth, (int)(m_data->m_glApp->m_window->getWidth() * m_data->m_glApp->m_window->getRetinaScale()));
	int sourceHeight = btMin(destinationHeight, (int)(m_data->m_glApp->m_window->getHeight() * m_data->m_glApp->m_window->getRetinaScale()));
	m_data->m_glApp->setViewport(sourceWidth, sourceHeight);

	if (numPixelsCopied)
		*numPixelsCopied = 0;

	int numTotalPixels = destinationWidth * destinationHeight;
	int numRemainingPixels = numTotalPixels - startPixelIndex;
	int numBytesPerPixel = 4;  //RGBA
	int numRequestedPixels = btMin(rgbaBufferSizeInPixels, numRemainingPixels);
	if (numRequestedPixels)
	{
		if (startPixelIndex == 0)
		{
			CommonCameraInterface* oldCam = getRenderInterface()->getActiveCamera();
			SimpleCamera tempCam;
			getRenderInterface()->setActiveCamera(&tempCam);
			getRenderInterface()->getActiveCamera()->setVRCamera(viewMatrix, projectionMatrix);
			{
				BT_PROFILE("renderScene");
				getRenderInterface()->renderScene();
			}

			{
				BT_PROFILE("copy pixels");
				btAlignedObjectArray<unsigned char> sourceRgbaPixelBuffer;
				btAlignedObjectArray<float> sourceDepthBuffer;
				//copy the image into our local cache
				sourceRgbaPixelBuffer.resize(sourceWidth * sourceHeight * numBytesPerPixel);
				sourceDepthBuffer.resize(sourceWidth * sourceHeight);
				{
					BT_PROFILE("getScreenPixels");
					m_data->m_glApp->getScreenPixels(&(sourceRgbaPixelBuffer[0]), sourceRgbaPixelBuffer.size(), &sourceDepthBuffer[0], sizeof(float) * sourceDepthBuffer.size());
				}

				m_data->m_rgbaPixelBuffer1.resize(destinationWidth * destinationHeight * numBytesPerPixel);
				m_data->m_depthBuffer1.resize(destinationWidth * destinationHeight);
				//rescale and flip
				{
					BT_PROFILE("resize and flip");
					for (int j = 0; j < destinationHeight; j++)
					{
						for (int i = 0; i < destinationWidth; i++)
						{
							int xIndex = int(float(i) * (float(sourceWidth) / float(destinationWidth)));
							int yIndex = int(float(destinationHeight - 1 - j) * (float(sourceHeight) / float(destinationHeight)));
							btClamp(xIndex, 0, sourceWidth);
							btClamp(yIndex, 0, sourceHeight);
							int bytesPerPixel = 4;  //RGBA