I wanna draw a pixel buffer directly on the screen with the Metal API. in OpenGL I can use glDrawPixels how to do it in Metal?

I init openGL now i wanna set glPixelZoom(pixelSizeX, -pixelSizeY); to dispaly a image with width and height to the entire window for this I do: rect:= window.frame; WindowBackingRect := window.convertRectToBacking(rect); pixelSizeX := WindowBackingRect.size.width / width / NSScreen.mainScreen.backingScaleFactor; pixelSizeY := WindowBackingRect.size.height / height / NSScreen.mainScreen.backingScaleFactor; under High Sierra 10.13.6 on an intel mac from 2011 NSScreen.mainScreen.backingScaleFactor return 1 because there is no retina. under Sonoma 14.3 an an intel mac from 2020 NSScreen.mainScreen.backingScaleFactor return 2 because of retina. this works correct. under Venture 13.6 on an aarch64 mac from 2020 NSScreen.mainScreen.backingScaleFactor returns 2 BUT the image is only half so big as it should be. (if i let the scale factor away on the new intel mac, the image is twice big as it should be. On the new AArch64 mac it is correct.) what to do?

MacOS CoreAudio buffer playback produces annoying noise between correct sound. I'm interested to play valid .wav data though the buffer. Why I'm playing a .wav? It has valid data. What I'm trying to achieve is to understand how to write correctly to the sound buffer. I'm porting a music engine to MacOS .... #include <string.h> #include <math.h> #include <unistd.h> #include <stdio.h> #include <AudioToolbox/AudioToolbox.h> FILE *fp; typedef struct TwavHeader{ char RIFF[4]; uint32_t RIFFChunkSize; char WAVE[4]; char fmt[4]; uint32_t Subchunk1Size; uint16_t AudioFormat; uint16_t NumOfChan; uint32_t SamplesPerSec; uint32_t bytesPerSec; uint16_t blockAlign; uint16_t bitsPerSample; char Subchunk2ID[4]; uint32_t Subchunk2Size; }TwavHeader; typedef struct SoundState { bool done; }SoundState; void auCallback(void *inUserData, AudioQueueRef queue, AudioQueueBufferRef buffer) { buffer->mAudioDataByteSize = 1024*4; int numToRead = buffer->mAudioDataByteSize / sizeof(float) * 2; void *p = malloc(numToRead); fread(p, numToRead,1,fp); void *myBuf = buffer->mAudioData; for (int i=0; i < numToRead / 2; i++) { uint16_t w = *(uint16_t *)&(p[i*sizeof(uint16_t)]); float f = ((float)w / (float)0x8000) - 1.0; *(float *)&(myBuf[i*sizeof(float)]) = f; } free(p); AudioQueueEnqueueBuffer(queue, buffer, 0, 0); } void checkError(OSStatus error){ if (error != noErr) { printf("Error: %d", error); exit(error); } } int main(int argc, const char * argv[]) { printf("START\n"); TwavHeader theHeader; fp = fopen("/Users/kirillkranz/Documents/mytralala-code/CoreAudioTest/unreal.wav", "r"); fread(&theHeader, sizeof(TwavHeader),1,fp); printf("%i\n",theHeader.bitsPerSample); AudioStreamBasicDescription auDesc = {}; auDesc.mSampleRate = theHeader.SamplesPerSec; auDesc.mFormatID = kAudioFormatLinearPCM; auDesc.mFormatFlags = kLinearPCMFormatFlagIsFloat | kLinearPCMFormatFlagIsPacked; auDesc.mBytesPerPacket = 8; auDesc.mFramesPerPacket = 1; auDesc.mBytesPerFrame = 8; auDesc.mChannelsPerFrame = 2; auDesc.mBitsPerChannel = 32; AudioQueueRef auQueue = 0; AudioQueueBufferRef auBuffers[2] ={}; // our persistent state for sound playback SoundState soundState= {}; soundState.done=false; OSStatus err; // most of the 0 and nullptr params here are for compressed sound formats etc. err = AudioQueueNewOutput(&auDesc, &auCallback, &soundState, 0, 0, 0, &auQueue); checkError(err); // generate buffers holding at most 1/16th of a second of data uint32_t bufferSize = auDesc.mBytesPerFrame * (auDesc.mSampleRate / 16); err = AudioQueueAllocateBuffer(auQueue, bufferSize, &(auBuffers[0])); checkError(err); err = AudioQueueAllocateBuffer(auQueue, bufferSize, &(auBuffers[1])); checkError(err); // prime the buffers auCallback(&soundState, auQueue, auBuffers[0]); auCallback(&soundState, auQueue, auBuffers[1]); // enqueue for playing AudioQueueEnqueueBuffer(auQueue, auBuffers[0], 0, 0); AudioQueueEnqueueBuffer(auQueue, auBuffers[1], 0, 0); // go! AudioQueueStart(auQueue, 0); char rxChar[10]; scanf( "%s", &rxChar); printf("FINISH"); fclose(fp); // be nice even it doesn't really matter at this point if (auQueue) AudioQueueDispose(auQueue, true); } what do I do wrong?