Avoid integer overflow

cuda_rasterizer/rasterizer_impl.cu

@@ -234,7 +234,7 @@ int CudaRasterizer::Rasterizer::forward(
 	dim3 block(BLOCK_X, BLOCK_Y, 1);
 
 	// Dynamically resize image-based auxiliary buffers during training
-	int img_chunk_size = required<ImageState>(width * height);
+	size_t img_chunk_size = required<ImageState>(width * height);
 	char* img_chunkptr = imageBuffer(img_chunk_size);
 	ImageState imgState = ImageState::fromChunk(img_chunkptr, width * height);
 
@@ -280,7 +280,7 @@ int CudaRasterizer::Rasterizer::forward(
 	int num_rendered;
 	cudaMemcpy(&num_rendered, geomState.point_offsets + P - 1, sizeof(int), cudaMemcpyDeviceToHost);
 
-	int binning_chunk_size = required<BinningState>(num_rendered);
+	size_t binning_chunk_size = required<BinningState>(num_rendered);
 	char* binning_chunkptr = binningBuffer(binning_chunk_size);
 	BinningState binningState = BinningState::fromChunk(binning_chunkptr, num_rendered);