feat: Add touch coordinate mapping and RTOS task yielding (#2481)

Co-authored-by: Julia Nguyen <julia@uxj.io>

lib/GfxRenderer/GfxRenderer.cpp

@@ -1506,6 +1506,20 @@ void GfxRenderer::displayBuffer(const HalDisplay::RefreshMode refreshMode) const
   display.displayBuffer(refreshMode, fadingFix);
 }
 
+void GfxRenderer::displayBufferAsync(const HalDisplay::RefreshMode refreshMode) const {
+  // The async path has no turn-off-screen hook, which the sunlight fading fix
+  // relies on; keep those users on the blocking path.
+  if (fadingFix) {
+    display.displayBuffer(refreshMode, fadingFix);
+    return;
+  }
+  display.displayBufferAsync(refreshMode);
+}
+
+void GfxRenderer::waitRefreshComplete() const { display.waitRefreshComplete(); }
+
+bool GfxRenderer::supportsAsyncRefresh() const { return !fadingFix && display.supportsAsyncRefresh(); }
+
 size_t GfxRenderer::readFramebufferRegion(int x, int y, int w, int h, uint8_t* dst, size_t dstCapacity) const {
   if (dst == nullptr || w <= 0 || h <= 0) return 0;
 
@@ -1652,6 +1666,35 @@ int GfxRenderer::getScreenHeight() const {
   return panelWidth;
 }
 
+void GfxRenderer::tapToLogical(float nx, float ny, int& outX, int& outY) const {
+  int phyX = static_cast<int>(nx * panelWidth);
+  int phyY = static_cast<int>(ny * panelHeight);
+  if (phyX < 0) phyX = 0;
+  if (phyX > panelWidth - 1) phyX = panelWidth - 1;
+  if (phyY < 0) phyY = 0;
+  if (phyY > panelHeight - 1) phyY = panelHeight - 1;
+
+  switch (orientation) {
+    case Portrait:
+      outX = panelHeight - 1 - phyY;
+      outY = phyX;
+      break;
+    case PortraitInverted:
+      outX = phyY;
+      outY = panelWidth - 1 - phyX;
+      break;
+    case LandscapeClockwise:
+      outX = panelWidth - 1 - phyX;
+      outY = panelHeight - 1 - phyY;
+      break;
+    case LandscapeCounterClockwise:
+    default:
+      outX = phyX;
+      outY = phyY;
+      break;
+  }
+}
+
 // Translate a logical rect through rotateCoordinates and take the bounding
 // box of its four corners on the physical panel. Output coords are inclusive
 // and clamped. Returns false if the rect ends up fully off-panel.

lib/GfxRenderer/GfxRenderer.h

@@ -134,7 +134,19 @@ class GfxRenderer {
   // Screen ops
   int getScreenWidth() const;
   int getScreenHeight() const;
+  void tapToLogical(float nx, float ny, int& outX, int& outY) const;
   void displayBuffer(HalDisplay::RefreshMode refreshMode = HalDisplay::FAST_REFRESH) const;
+  // Non-blocking refresh: starts the waveform and returns so CPU work (e.g.
+  // grayscale strip rendering) can overlap the panel's refresh time. The
+  // framebuffer must stay untouched until waitRefreshComplete(). Falls back to
+  // a blocking refresh when fadingFix is enabled or the panel lacks deferral
+  // support. See HalDisplay::displayBufferAsync for the baseline contract.
+  void displayBufferAsync(HalDisplay::RefreshMode refreshMode = HalDisplay::FAST_REFRESH) const;
+  void waitRefreshComplete() const;
+  // True when displayBufferAsync() genuinely overlaps: panel defers and
+  // fadingFix isn't forcing the blocking path. Callers can skip overlap
+  // scaffolding (e.g. whole-plane grayscale buffers) when false.
+  bool supportsAsyncRefresh() const;
   // EXPERIMENTAL: Windowed update - display only a rectangular region
   // void displayWindow(int x, int y, int width, int height) const;
   void invertScreen() const;