Add ability to scroll 1bpp Sprites

New example added: Sprite_scroll_1bit

Extensions/Sprite.cpp

@@ -657,7 +657,21 @@ void TFT_eSprite::scroll(int16_t dx, int16_t dy)
       fyp += iw;
     }
   }
-  else return; // TODO add scroll for 1 bpp
+  else if (_bpp == 1)
+  {
+    if (dx >  0) { tx += w; fx += w; } // Start from right edge
+    while (h--)
+    { // move pixels one by one
+      for (uint16_t xp = 0; xp < w; xp++)
+      {
+        if (dx <= 0) drawPixel(tx + xp, ty, readPixel(fx + xp, fy));
+        if (dx >  0) drawPixel(tx - xp, ty, readPixel(fx - xp, fy));
+      }
+      if (dy <= 0)  { ty++; fy++; }
+      else  { ty--; fy--; }
+    }
+  }
+  else return; // Not 1, 8 or 16 bpp
 
   // Fill the gap left by the scrolling
   if (dx > 0) fillRect(_sx, _sy, dx, _sh, _scolor);

examples/Sprite/Sprite_scroll_1bit/Sprite_scroll_1bit.ino

+/*
+  Sketch to show scrolling of the graphics in sprites.
+
+  This sketch scrolls a 1 bit per pixel (1 bpp) Sprite.
+  
+  In a 1 bit Sprite any colour except TFT_BLACK turns a pixel "ON"
+  TFT_BLACK turns a pixel "OFF".
+
+  The 1 bpp Sprite has a unique property that other bit depth Sprites
+  do not have, your can set the rotation of the coordinate frame e.g.:
+  spr.setRotation(1);
+
+  This is similar to screen rotations, so for example text can
+  be drawn rotated:
+    Rotation 0: Normal orientation
+    Rotation 1: Coordinate frame rotated clockwise 90 degrees
+    Rotation 2: Coordinate frame rotated clockwise 180 degrees (upside down)
+    Rotation 3: Coordinate frame rotated clockwise 270 degrees
+
+  When pushSprite is used the sprite is drawn with the width and height
+  staying as created, so the created Sprite itself is not rotated during
+  rendering. See stext2 sprite example below at line 83.
+
+  ON and OFF pixels can be set to any two colours before
+  rendering to the screen with pushSprite, for example:
+  tft.setBitmapColor(ON_COLOR, OFF_COLOR);
+
+  Scrolling moves the pixels in a defined rectangle within
+  the Sprite. By defalt the whole sprite is scrolled.
+  The gap left by scrolling is filled with a defined colour.
+
+  Example for library:
+  https://github.com/Bodmer/TFT_eSPI
+
+  A Sprite is notionally an invisible graphics screen that is
+  kept in the processors RAM. Graphics can be drawn into the
+  Sprite just as it can be drawn directly to the screen. Once
+  the Sprite is completed it can be plotted onto the screen in
+  any position. If there is sufficient RAM then the Sprite can
+  be the same size as the screen and used as a frame buffer.
+
+  A 1 bit Sprite occupies (width * height)/8 bytes in RAM.
+
+*/
+
+#include <TFT_eSPI.h>
+
+TFT_eSPI tft = TFT_eSPI();
+
+TFT_eSprite graph1 = TFT_eSprite(&tft); // Sprite object graph1
+
+TFT_eSprite stext1 = TFT_eSprite(&tft); // Sprite object stext1
+
+TFT_eSprite stext2 = TFT_eSprite(&tft); // Sprite object stext2
+
+int graphVal = 1;
+int delta = 1;
+int grid = 0;
+int tcount = 0;
+
+//==========================================================================================
+void setup() {
+  tft.init();
+  tft.fillScreen(TFT_BLACK);
+
+  // Create a sprite for the graph
+  graph1.setColorDepth(1);
+  graph1.createSprite(128, 61);
+  graph1.fillSprite(TFT_BLACK); // Note: Sprite is filled with black when created
+
+  // The scroll area is set to the full sprite size upon creation of the sprite
+  // but we can change that by defining a smaller area using "setScrollRect()"if needed
+  // parameters are x,y,w,h,color as in drawRect(), the color fills the gap left by scrolling
+  //graph1.setScrollRect(64, 0, 64, 61, TFT_BLACK);  // Try this line to change the graph scroll area
+
+  // Create a sprite for the scrolling numbers
+  stext1.setColorDepth(1);
+  stext1.createSprite(32, 64);
+  stext1.fillSprite(TFT_BLACK); // Fill sprite with blue
+  stext1.setScrollRect(0, 0, 32, 64, TFT_BLACK);     // here we set scroll gap fill color to blue
+  stext1.setTextColor(TFT_WHITE); // White text, no background
+  stext1.setTextDatum(BR_DATUM);  // Bottom right coordinate datum
+
+  // Create a sprite for Hello World
+  stext2.setColorDepth(1);
+  stext2.createSprite(16, 80); // Narrow and tall
+  stext2.setRotation(1);       // Plot with 90 deg. clockwise rotation
+  stext2.fillSprite(TFT_BLACK);
+  stext2.setScrollRect(0, 0, 40, 16, TFT_BLACK); // Scroll the "Hello" in the first 40 pixels
+  stext2.setTextColor(TFT_WHITE); // White text, no background
+}
+
+//==========================================================================================
+void loop() {
+  // Draw point in graph1 sprite at far right edge (this will scroll left later)
+  graph1.drawFastVLine(127,60-graphVal,2,TFT_WHITE); // draw 2 pixel point on graph
+
+  // Draw number in stext1 sprite at 31,63 (bottom right datum set)
+  stext1.drawNumber(graphVal, 31, 63, 2); // plot value in font 2
+
+  // Push the sprites onto the TFT at specied coordinates
+  tft.setBitmapColor(TFT_WHITE, TFT_BLUE); // Specify the colours of the ON and OFF pixels
+  graph1.pushSprite(0, 0);
+
+  tft.setBitmapColor(TFT_GREEN, TFT_BLACK);
+  stext1.pushSprite(0, 64);
+
+  tft.setBitmapColor(TFT_BLACK, TFT_YELLOW);
+  stext2.pushSprite(60, 70);
+
+  // Change the value to plot
+  graphVal+=delta;
+
+  // If the value reaches a limit, then change delta of value
+  if (graphVal >= 60)     delta = -1;  // ramp down value
+  else if (graphVal <= 1) delta = +1;  // ramp up value
+
+  delay(50); // wait so things do not scroll too fast
+
+  // Now scroll the sprites scroll(dt, dy) where:
+  // dx is pixels to scroll, left = negative value, right = positive value
+  // dy is pixels to scroll, up = negative value, down = positive value
+  graph1.scroll(-1, 0); // scroll graph 1 pixel left, 0 up/down
+  stext1.scroll(0,-16); // scroll stext 0 pixels left/right, 16 up
+  stext2.scroll(1);     // scroll stext 1 pixel right, up/down default is 0
+
+  // Draw the grid on far right edge of sprite as graph has now moved 1 pixel left
+  grid++;
+  if (grid >= 10)
+  { // Draw a vertical line if we have scrolled 10 times (10 pixels)
+    grid = 0;
+    graph1.drawFastVLine(127, 0, 61, TFT_WHITE); // draw line on graph
+  }
+  else
+  { // Otherwise draw points spaced 10 pixels for the horizontal grid lines
+    for (int p = 0; p <= 60; p += 10) graph1.drawPixel(127, p, TFT_WHITE);
+  }
+
+  tcount--;
+  if (tcount <=0)
+  { // If we have scrolled 40 pixels the redraw text
+    tcount = 40;
+    stext2.drawString("Hello World", 6, 0, 2); // draw at 6,0 in sprite, font 2
+  }
+
+} // Loop back and do it all again
+//==========================================================================================