OutputTinyGPU.h

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#pragma once
#include <TinyGPU.h>  // https://github.com/pschatzmann/TinyGPU
#include <TinyGPU/DisplayDriverSPI.h>  // ILI9341Driver
#include <TinyGPU/SurfaceWithExternalBuffer.h>  // zero-copy write() path
 
#include "AudioTools/Video/CodecVideo.h"
 
namespace audio_tools {
 
class OutputTinyGPU : public VideoOutput {
 public:
  OutputTinyGPU(ILI9341Driver<RGB565>& driver, int width, int height,
                int pinBacklight, int bandHeight = 40)
      : tftDriver(driver),
        width(width),
        height(height),
        kPinBacklight(pinBacklight),
        kBandHeight(bandHeight) {}
 
  bool begin() {
    if (kPinBacklight >= 0) {
      pinMode(kPinBacklight, OUTPUT);
      digitalWrite(kPinBacklight, HIGH);
    }
    tftDriver.begin();
    clearScreen();
 
    return true;
  }
 
  void setVideoInfoSource(VideoInfoSource& source) { p_info = &source; }
 
  void setVideoInfo(VideoInfo info) { info_ = info; }
 
  size_t write(const uint8_t* data, size_t len) override {
    if (p_info != nullptr) {
      info_ = p_info->videoInfo();
    }
 
    if (info_.width == 0 || info_.height == 0) {
      LOGE("OutputTinyGPU: invalid video size: %d x %d", (int)info_.width,
           (int)info_.height);
      return 0;
    }
 
    size_t needed = (size_t)info_.width * info_.height * sizeof(RGB565);
    if (len < needed) {
      LOGE("OutputTinyGPU: frame too small: %d < %d bytes", (int)len,
           (int)needed);
      return 0;
    }
 
    // View directly over the caller's buffer - no allocation, no copy.
    SurfaceWithExternalBuffer<RGB565> frame;
    frame.setExternalBuffer(const_cast<uint8_t*>(data), len);
    frame.resize(info_.width, info_.height);
    tftDriver.writeData(frame, 0, 0);
 
    return len;
  }
 
  void clearScreen() {
    SurfaceRGB565 band(width, kBandHeight, FontRGB565);
    band.begin();
    band.clear(RGB565(0, 0, 0));
    for (int y = 0; y < height; y += kBandHeight) {
      tftDriver.writeData(band, 0, y);
    }
    band.end();
  }
 
 protected:
  int width = 320;
  int height = 240;
  int kPinBacklight;
  int kBandHeight;
  VideoInfoSource* p_info = nullptr;
  VideoInfo info_;
  ILI9341Driver<RGB565>& tftDriver;
};
 
}  // namespace audio_tools