PicoGraphics: 1bit/1bitY dither all drawing operations.

Note: Pen now ranges from 0 (black) to 15 (white). Values between will be dithered ala Badger 2040.

libraries/pico_graphics/pico_graphics.hpp

@@ -257,7 +257,6 @@ namespace pimoroni {
 
       void set_pixel(const Point &p) override;
       void set_pixel_span(const Point &p, uint l) override;
-      void set_pixel_dither(const Point &p, const uint8_t &c) override;
 
       static size_t buffer_size(uint w, uint h) {
           return w * h / 8;
@@ -274,7 +273,6 @@ namespace pimoroni {
 
       void set_pixel(const Point &p) override;
       void set_pixel_span(const Point &p, uint l) override;
-      void set_pixel_dither(const Point &p, const uint8_t &c) override;
 
       static size_t buffer_size(uint w, uint h) {
           return w * h / 8;

libraries/pico_graphics/pico_graphics_pen_1bit.cpp

@@ -11,11 +11,11 @@ namespace pimoroni {
   }
 
   void PicoGraphics_Pen1Bit::set_pen(uint c) {
-    color = c != 0 ? 1 : 0;
+    color = c;
   }
 
   void PicoGraphics_Pen1Bit::set_pen(uint8_t r, uint8_t g, uint8_t b) {
-    color = r != 0 || g != 0 || b != 0 ? 1 : 0;
+    color = std::max(r, std::max(g, b)) >> 4;
   }
 
   void PicoGraphics_Pen1Bit::set_pixel(const Point &p) {
@@ -25,46 +25,33 @@ namespace pimoroni {
 
     uint bo = 7 - (p.x & 0b111);
 
+    uint8_t _dc = 0;
+
+    if(color == 0) {
+      _dc = 0;
+    } else if (color == 15) {
+      _dc = 1;
+    } else {
+      uint8_t _dmv = dither16_pattern[(p.x & 0b11) | ((p.y & 0b11) << 2)];
+      _dc = color > _dmv ? 1 : 0;
+    }
+
     // forceably clear the bit
     *f &= ~(1U << bo); 
 
     // set pixel
-    *f |= (color << bo);
+    *f |= (_dc << bo);
   }
 
   void PicoGraphics_Pen1Bit::set_pixel_span(const Point &p, uint l) {
-    // pointer to byte in framebuffer that contains this pixel
-    uint8_t *buf = (uint8_t *)frame_buffer;
-    uint8_t *f = &buf[(p.x / 8) + (p.y * bounds.w / 8)];
-
-    uint bo = 7 - (p.x & 0b111);
-
-    // TODO: this could trivially be sped up by processing single bits only at 
-    // the start and the end of the span and writing full bytes (8 pixels at
-    // a time) in the middle portion of the span. would only be more efficient
-    // for longer spans (probably around 20 pixels or more)
+    Point lp = p;
+    if(p.x + (int)l >= bounds.w) {
+      l = bounds.w - p.x;
+    }
     while(l--) {
-      // forceably clear the bit and then set to the correct value
-      *f &= ~(1U << bo); 
-      *f |= (color << bo);
-
-      if(bo == 0) { // last bit of this byte?
-        // move to next byte in framebuffer and reset the bit offset
-        f++; bo = 8;
-      }
-
-      bo--;
+        set_pixel(lp);
+        lp.x++;
     }
   }
 
-  void PicoGraphics_Pen1Bit::set_pixel_dither(const Point &p, const uint8_t &c) {
-    if(!bounds.contains(p)) return;
-
-    uint8_t _dmv = dither16_pattern[(p.x & 0b11) | ((p.y & 0b11) << 2)];
-    uint8_t _dc = c >> 4;
-    color = _dc > _dmv ? 1 : 0;
-
-    set_pixel(p);
-  };
-
 }

libraries/pico_graphics/pico_graphics_pen_1bitY.cpp

@@ -11,11 +11,11 @@ namespace pimoroni {
   }
 
   void PicoGraphics_Pen1BitY::set_pen(uint c) {
-    color = c != 0 ? 1 : 0;
+    color = c;
   }
 
   void PicoGraphics_Pen1BitY::set_pen(uint8_t r, uint8_t g, uint8_t b) {
-    color = r != 0 || g != 0 || b != 0 ? 1 : 0;
+    color = std::max(r, std::max(g, b));
   }
 
   void PicoGraphics_Pen1BitY::set_pixel(const Point &p) {
@@ -25,29 +25,33 @@ namespace pimoroni {
 
     uint bo = 7 - (p.y & 0b111);
 
+    uint8_t _dc = 0;
+
+    if(color == 0) {
+      _dc = 0;
+    } else if (color == 15) {
+      _dc = 1;
+    } else {
+      uint8_t _dmv = dither16_pattern[(p.x & 0b11) | ((p.y & 0b11) << 2)];
+      _dc = color > _dmv ? 1 : 0;
+    }
+
     // forceably clear the bit
     *f &= ~(1U << bo); 
 
     // set pixel
-    *f |= (color << bo);
+    *f |= (_dc << bo);
   }
 
   void PicoGraphics_Pen1BitY::set_pixel_span(const Point &p, uint l) {
-    Point po(p);
+    Point lp = p;
+    if(p.x + (int)l >= bounds.w) {
+      l = bounds.w - p.x;
+    }
     while(l--) {
-      set_pixel(po);
-      po.x++;
+        set_pixel(lp);
+        lp.x++;
     }
   }
 
-  void PicoGraphics_Pen1BitY::set_pixel_dither(const Point &p, const uint8_t &c) {
-    if(!bounds.contains(p)) return;
-
-    uint8_t _dmv = dither16_pattern[(p.x & 0b11) | ((p.y & 0b11) << 2)];
-    uint8_t _dc = c >> 4;
-    color = _dc > _dmv ? 1 : 0;
-
-    set_pixel(p);
-  };
-
 }

micropython/modules/jpegdec/jpegdec.cpp

@@ -90,7 +90,8 @@ MICROPY_EVENT_POLL_HOOK
         uint8_t *pixel = (uint8_t *)pDraw->pPixels;
         for(int y = 0; y < pDraw->iHeight; y++) {
             for(int x = 0; x < pDraw->iWidth; x++) {
-                current_graphics->set_pixel_dither({pDraw->x + x, pDraw->y + y}, *pixel);
+                current_graphics->set_pen((uint8_t)(*pixel >> 4));
+                current_graphics->set_pixel({pDraw->x + x, pDraw->y + y});
                 pixel++;
             }
         }