etc

Author: thinkyhead

Marlin/src/lcd/tft/canvas.cpp

@@ -132,7 +132,7 @@ void Canvas::addImage(int16_t x, int16_t y, MarlinImage image, uint16_t *colors)
 
     static struct {
       bool has_rle_state = false;
-      uint16_t dstx, dsty, srcx, srcy;
+      int16_t dstx, dsty, srcx, srcy;
       uint32_t rle_offset;
     } rle_state;
 
@@ -146,23 +146,23 @@ void Canvas::addImage(int16_t x, int16_t y, MarlinImage image, uint16_t *colors)
               dsty = y, dstx = x;                   // Destination line / column index
 
       uint16_t color = 0;                           // Persist the last fetched color value
-      if (rle_state.has_rle_state) {                // do we have rle position data
+      if (rle_state.has_rle_state) {                // do we have RLE position data?
+        rle_state.has_rle_state = false;            // invalidate stored RLE state
         dstx = rle_state.dstx;                      // restore required states
         dsty = rle_state.dsty;
         srcx = rle_state.srcx;
         srcy = rle_state.srcy;
-        bytedata = (uint8_t *)images[image].data + rle_state.rle_offset;  // restart decode from here instead of the start of data
-        rle_state.has_rle_state = false;            // invalidate stored rle state
+        bytedata = (uint8_t *)images[image].data + rle_state.rle_offset;  // Restart decode from here instead of the start of data
       }
 
       bool done = false;
       while (!done) {
-        if (dsty >= endLine -1 || srcy >= image_height -1) { // Store state?
-          rle_state.dstx = dstx;                    // save required states
+        if (dsty >= endLine - 1 || srcy >= image_height - 1) { // Store state?
+          rle_state.dstx = dstx;                    // Save required states
           rle_state.dsty = dsty;
           rle_state.srcx = srcx;
           rle_state.srcy = srcy;
-          rle_state.rle_offset = bytedata - (uint8_t *)images[image].data;; // Keep these for skipping full rle decode on future iteratons
+          rle_state.rle_offset = bytedata - (uint8_t *)images[image].data;; // Keep these for skipping full RLE decode on future iteratons
         }
 
         uint8_t count = *bytedata++;                // Get the count byte
@@ -193,7 +193,7 @@ void Canvas::addImage(int16_t x, int16_t y, MarlinImage image, uint16_t *colors)
             srcx = 0; dstx = x;                     // May be shifted within the canvas, but usually not
             if (dsty >= endLine || srcy >= image_height) { // Done with the segment or the image?
               done = true;                          // Set a flag to end the loop...
-              rle_state.has_rle_state = true;       // rle state is stored
+              rle_state.has_rle_state = true;       // RLE state is stored
               break;                                // ...and break out of while(count--)
             }
           }