1 #include "IOStream.h" 2 3 #include "GL2Encoder.h" 4 5 #include <GLES3/gl31.h> 6 7 #include <vector> 8 9 void IOStream::readbackPixels(void* context, int width, int height, unsigned int format, unsigned int type, void* pixels) { 10 GL2Encoder *ctx = (GL2Encoder *)context; 11 assert (ctx->state() != NULL); 12 13 int startOffset = 0; 14 int pixelRowSize = 0; 15 int totalRowSize = 0; 16 int skipRows = 0; 17 18 ctx->state()->getPackingOffsets2D(width, height, format, type, 19 &startOffset, 20 &pixelRowSize, 21 &totalRowSize, 22 &skipRows); 23 24 size_t pixelDataSize = 25 ctx->state()->pixelDataSize( 26 width, height, 1, format, type, 1 /* is pack */); 27 28 if (startOffset == 0 && 29 pixelRowSize == totalRowSize) { 30 // fast path 31 readback(pixels, pixelDataSize); 32 } else if (pixelRowSize == totalRowSize) { 33 // fast path but with skip in the beginning 34 std::vector<char> paddingToDiscard(startOffset, 0); 35 readback(&paddingToDiscard[0], startOffset); 36 readback((char*)pixels + startOffset, pixelDataSize - startOffset); 37 } else { 38 int totalReadback = 0; 39 40 if (startOffset > 0) { 41 std::vector<char> paddingToDiscard(startOffset, 0); 42 readback(&paddingToDiscard[0], startOffset); 43 totalReadback += startOffset; 44 } 45 // need to read back row by row 46 size_t paddingSize = totalRowSize - pixelRowSize; 47 std::vector<char> paddingToDiscard(paddingSize, 0); 48 49 char* start = (char*)pixels + startOffset; 50 51 for (int i = 0; i < height; i++) { 52 readback(start, pixelRowSize); 53 totalReadback += pixelRowSize; 54 readback(&paddingToDiscard[0], paddingSize); 55 totalReadback += paddingSize; 56 start += totalRowSize; 57 } 58 } 59 } 60
