diff --git a/apps/graph/graph/cursor_view.cpp b/apps/graph/graph/cursor_view.cpp
index e3174a32f..f635c3185 100644
--- a/apps/graph/graph/cursor_view.cpp
+++ b/apps/graph/graph/cursor_view.cpp
@@ -1,6 +1,5 @@
 #include "cursor_view.h"
 
 void CursorView::drawRect(KDRect rect) const {
-  KDColor cursorColor = KDColorRed;
-  KDFillRect(rect, &cursorColor, 1);
+  KDFillRect(rect, KDColorRed);
 }
diff --git a/apps/graph/graph/graph_view.cpp b/apps/graph/graph/graph_view.cpp
index 3ea307193..6a39f5464 100644
--- a/apps/graph/graph/graph_view.cpp
+++ b/apps/graph/graph/graph_view.cpp
@@ -8,7 +8,11 @@ constexpr int kNumberOfMainGridLines = 5;
 constexpr int kNumberOfSecondaryGridLines = 4;
 
 GraphView::GraphView() :
+#if GRAPH_VIEW_IS_TILED
+  TiledView(),
+#else
   View(),
+#endif
   m_cursorView(CursorView()),
   m_cursorPosition(KDPointZero),
   m_xMin(-2.0f),
@@ -39,36 +43,65 @@ void GraphView::layoutSubviews() {
   m_cursorView.setFrame(cursorFrame);
 }
 
+#if GRAPH_VIEW_IS_TILED
+KDColor * GraphView::tile() const {
+  return (KDColor *)m_tile;
+}
+
+KDSize GraphView::tileSize() const {
+  return {kTileWidth, kTileHeight};
+}
+
+void GraphView::drawTile(KDRect rect) const {
+#else
 void GraphView::drawRect(KDRect rect) const {
-  KDColor backgroundColor = KDColorWhite;
-  KDFillRect(rect, &backgroundColor, 1);
+#endif
+  KDFillRect(rect, KDColorWhite);
   drawGrid(rect);
   drawAxes(rect);
   drawFunction(rect);
+  /*
+
+  constexpr int maskLength = 3;
+  uint8_t mask[maskLength] = {
+#if 1
+    0x10, 0x70, 0xE0,
+#else
+    0x00, 0x30, 0x73, 0x30, 0x00,
+    0x30, 0xfb, 0xff, 0xfb, 0x30,
+    0x73, 0xff, 0xff, 0xff, 0x73,
+    0x30, 0xfb, 0xff, 0xfb, 0x30,
+    0x00, 0x30, 0x73, 0x30, 0x00
+#endif
+  };
+
+  KDColor red = KDColorRed;
+  KDBlitRect(rect, &red, 1, mask, maskLength);
+  */
 }
 
-void GraphView::drawLine(KDRect rect, Axis axis, float coordinate, KDColor color) const {
+void GraphView::drawLine(KDRect rect, Axis axis, float coordinate, KDColor color, KDCoordinate thickness) const {
   KDRect lineRect;
   switch(axis) {
     case Axis::Horizontal:
       lineRect.x = rect.x;
       lineRect.y = floatToPixel(Axis::Vertical, coordinate);
       lineRect.width = rect.width;
-      lineRect.height = 1;
+      lineRect.height = thickness;
       break;
     case Axis::Vertical:
       lineRect.x = floatToPixel(Axis::Horizontal, coordinate);
       lineRect.y = rect.y;
-      lineRect.width = 1;
+      lineRect.width = thickness;
       lineRect.height = rect.height;
       break;
   }
-  KDFillRect(lineRect, &color, 1);
+  KDFillRect(lineRect, color);
 }
 
 void GraphView::drawAxes(KDRect rect) const {
-  drawLine(rect, Axis::Horizontal, 0.0f, kAxisColor);
-  drawLine(rect, Axis::Vertical, 0.0f, kAxisColor);
+  drawLine(rect, Axis::Horizontal, 0.0f, kAxisColor, 2);
+  drawLine(rect, Axis::Vertical, 0.0f, kAxisColor, 2);
 }
 
 void GraphView::drawGridLines(KDRect rect, Axis axis, int count, KDColor color) const {
@@ -113,11 +146,80 @@ KDCoordinate GraphView::floatToPixel(Axis axis, float f) const {
 }
 
 void GraphView::drawFunction(KDRect rect) const {
-  KDPoint p = KDPointZero;
-  for (p.x=rect.x; p.x<(rect.x+rect.width); p.x++) {
+  KDPoint p;
+
+  constexpr KDCoordinate stampSize = 5;
+
+  uint8_t mask[stampSize*stampSize] = {
+    0x00, 0x30, 0x73, 0x30, 0x00,
+    0x30, 0xfb, 0xff, 0xfb, 0x30,
+    0x73, 0xff, 0xff, 0xff, 0x73,
+    0x30, 0xfb, 0xff, 0xfb, 0x30,
+    0x00, 0x30, 0x73, 0x30, 0x00
+  };
+
+  KDColor workingBuffer[stampSize*stampSize];
+
+  for (p.x=rect.x-stampSize; p.x<(rect.x+rect.width); p.x++) {
     float x = pixelToFloat(Axis::Horizontal, p.x);
     float y = (x-1)*(x+1)*x;
     p.y = floatToPixel(Axis::Vertical, y);
-    KDSetPixel(p, KDColorRGB(0xCF, 0, 0));
+    KDRect stampRect;
+    stampRect.origin = p;
+    stampRect.width = stampSize;
+    stampRect.height = stampSize;
+    //KDColor red = KDColorRed;
+    KDFillRectWithMask(stampRect, KDColorRed, mask, workingBuffer);
+    //KDBlitRect(stampRect, &red, {1,1}, mask, {stampSize,stampSize});
   }
 }
+
+#if 0
+
+void GraphView::drawFunction(KDRect rect) const {
+  /* Naive algorithm: iterate on pixels horizontally
+   * Actually, this is kinda optimal. If two consecutive pixels don't touch
+   * (i.e. they have a y-difference greater than 1), just draw a vertical line.
+   * This may seem stupid but is kinda good actually. */
+  KDCoordinate previousPixelY;
+  KDCoordinate pixelX;
+
+  KDColor curveColor = KDColorRGB(0xFF, 0, 0);
+#define ANTI_ALIASING
+#ifdef ANTI_ALIASING
+  KDColor antiAliasingColor = KDColorRGB(0, 0xFF, 0);
+#endif
+
+  for (pixelX=rect.x; pixelX<(rect.x+rect.width); pixelX++) {
+    float x = pixelToFloat(Axis::Horizontal, pixelX);
+    float y = (x-1)*(x+1)*x;
+    KDCoordinate pixelY = floatToPixel(Axis::Vertical, y);
+    KDRect r;
+    r.x = pixelX;
+    if (pixelY < previousPixelY) {
+      r.y = pixelY;
+      r.height = previousPixelY-pixelY;
+      KDPoint p;
+      p.x = pixelX-1;
+      p.y = previousPixelY+3;
+      KDSetPixel(p, KDColorRGB(0x00, 0xFF, 0x00));
+      p.x = pixelX;
+      p.y = pixelY-1;
+      KDSetPixel(p, KDColorRGB(0x00, 0xFF, 0x00));
+    } else {
+      r.y = previousPixelY;
+      r.height = pixelY - previousPixelY;
+    }
+    if (r.height == 0) {
+      r.height = 1;
+    }
+    r.width = 1;
+
+    r.width += 2;
+    r.height += 2;
+    //KDFillRectWithPattern(r, antialiasedDot);
+    KDFillRect(r, KDColorRGB(0xFF, 0, 0));
+    previousPixelY = pixelY;
+  }
+}
+#endif
diff --git a/apps/graph/graph/graph_view.h b/apps/graph/graph/graph_view.h
index c82ea4886..cf251f237 100644
--- a/apps/graph/graph/graph_view.h
+++ b/apps/graph/graph/graph_view.h
@@ -4,10 +4,27 @@
 #include <escher.h>
 #include "cursor_view.h"
 
-class GraphView : public View {
+#define GRAPH_VIEW_IS_TILED 1
+
+class GraphView : public
+#if GRAPH_VIEW_IS_TILED
+                  TiledView
+#else
+                  View
+#endif
+{
 public:
   GraphView();
+
+#if GRAPH_VIEW_IS_TILED
+  KDColor * tile() const override;
+  KDSize tileSize() const override;
+  void drawTile(KDRect rect) const override;
+#else
   void drawRect(KDRect rect) const override;
+#endif
+
+//  void drawRect(KDRect rect) const override;
   void moveCursorRight();
 private:
   int numberOfSubviews() const override;
@@ -27,13 +44,17 @@ private:
   KDCoordinate floatToPixel(Axis axis, float f) const;
 
   void drawLine(KDRect rect, Axis axis,
-      float coordinate, KDColor color) const;
+      float coordinate, KDColor color, KDCoordinate thickness = 1) const;
 
   void drawAxes(KDRect rect) const;
   void drawGrid(KDRect rect) const;
   void drawGridLines(KDRect rect, Axis axis, int count, KDColor color) const;
   void drawFunction(KDRect rect) const;
 
+  static constexpr KDCoordinate kTileWidth = 32;
+  static constexpr KDCoordinate kTileHeight = 32;
+  KDColor m_tile[kTileWidth*kTileHeight];
+
   CursorView m_cursorView;
   KDPoint m_cursorPosition;
 
diff --git a/apps/graph/list/function_cell.cpp b/apps/graph/list/function_cell.cpp
index f9f19e28b..a602ba137 100644
--- a/apps/graph/list/function_cell.cpp
+++ b/apps/graph/list/function_cell.cpp
@@ -10,7 +10,7 @@ FunctionCell::FunctionCell() :
 
 void FunctionCell::drawRect(KDRect rect) const {
   KDColor background = m_even ? KDColorRGB(0xEE, 0xEE, 0xEE) : KDColorRGB(0x77,0x77,0x77);
-  KDFillRect(rect, &background, 1);
+  KDFillRect(rect, background);
   KDDrawString(m_message, KDPointZero, m_focused);
 }
 
diff --git a/escher/Makefile b/escher/Makefile
index fd06d6e5c..069d9e9b3 100644
--- a/escher/Makefile
+++ b/escher/Makefile
@@ -13,6 +13,7 @@ objs += $(addprefix escher/src/,\
   table_view.o\
   text_field.o\
   text_view.o\
+  tiled_view.o\
   view.o\
   view_controller.o\
   window.o\
diff --git a/escher/include/escher.h b/escher/include/escher.h
index 159c83b31..b97e6f615 100644
--- a/escher/include/escher.h
+++ b/escher/include/escher.h
@@ -10,6 +10,7 @@
 #include <escher/text_view.h>
 #include <escher/tab_view_controller.h>
 #include <escher/table_view.h>
+#include <escher/tiled_view.h>
 #include <escher/view.h>
 #include <escher/view_controller.h>
 #include <escher/window.h>
diff --git a/escher/include/escher/tiled_view.h b/escher/include/escher/tiled_view.h
new file mode 100644
index 000000000..046e5cad0
--- /dev/null
+++ b/escher/include/escher/tiled_view.h
@@ -0,0 +1,16 @@
+#ifndef ESCHER_TILED_VIEW_H
+#define ESCHER_TILED_VIEW_H
+
+#include <escher/view.h>
+
+class TiledView : public View {
+  using View::View;
+protected:
+  void drawRect(KDRect rect) const override;
+  virtual void drawTile(KDRect rect) const = 0;
+
+  virtual KDColor * tile() const = 0;
+  virtual KDSize tileSize() const = 0;
+};
+
+#endif
diff --git a/escher/src/scroll_view_indicator.cpp b/escher/src/scroll_view_indicator.cpp
index e3df94114..0b693288f 100644
--- a/escher/src/scroll_view_indicator.cpp
+++ b/escher/src/scroll_view_indicator.cpp
@@ -15,7 +15,7 @@ ScrollViewIndicator::ScrollViewIndicator(ScrollViewIndicator::Direction directio
 }
 
 void ScrollViewIndicator::drawRect(KDRect rect) const {
-  KDFillRect(bounds(), &k_backgroundColor, 1);
+  KDFillRect(bounds(), k_backgroundColor);
   KDRect indicatorFrame;
   if (m_direction == Direction::Horizontal) {
   indicatorFrame.x = m_start*m_frame.width;
@@ -29,7 +29,7 @@ void ScrollViewIndicator::drawRect(KDRect rect) const {
     indicatorFrame.width = m_frame.width;
     indicatorFrame.height = (m_end-m_start)*m_frame.height;
   }
-  KDFillRect(indicatorFrame, &k_indicatorColor, 1);
+  KDFillRect(indicatorFrame, k_indicatorColor);
 }
 
 void ScrollViewIndicator::setStart(float start) {
diff --git a/escher/src/solid_color_view.cpp b/escher/src/solid_color_view.cpp
index cf8101154..9c0506c9a 100644
--- a/escher/src/solid_color_view.cpp
+++ b/escher/src/solid_color_view.cpp
@@ -7,7 +7,7 @@ SolidColorView::SolidColorView(KDColor color) :
 }
 
 void SolidColorView::drawRect(KDRect rect) const {
-  KDFillRect(rect, &m_color, 1);
+  KDFillRect(rect, m_color);
 }
 
 #if ESCHER_VIEW_LOGGING
diff --git a/escher/src/tab_view.cpp b/escher/src/tab_view.cpp
index 679c5372c..3b4502358 100644
--- a/escher/src/tab_view.cpp
+++ b/escher/src/tab_view.cpp
@@ -13,7 +13,7 @@ TabView::TabView() :
 
 void TabView::drawRect(KDRect rect) const {
   KDColor backgroundColor = KDColorRGB(0xb5, 0x1d, 0xab);
-  KDFillRect(rect, &backgroundColor, 1);
+  KDFillRect(rect, backgroundColor);
 }
 
 void TabView::addTabNamed(const char * name) {
diff --git a/escher/src/tiled_view.cpp b/escher/src/tiled_view.cpp
new file mode 100644
index 000000000..b2b341810
--- /dev/null
+++ b/escher/src/tiled_view.cpp
@@ -0,0 +1,53 @@
+#include <escher/tiled_view.h>
+#include <assert.h>
+
+static KDFrameBuffer sCurrentTile;
+
+void tilePushRect(KDRect rect, const KDColor * pixels) {
+  KDFramePushRect(&sCurrentTile, rect, pixels);
+}
+void tilePushRectUniform(KDRect rect, KDColor color) {
+  KDFramePushRectUniform(&sCurrentTile, rect, color);
+}
+
+void tilePullRect(KDRect rect, KDColor * pixels) {
+  KDFramePullRect(&sCurrentTile, rect, pixels);
+}
+
+static KDContext sTileContext = {
+  {
+    &tilePushRect,
+    &tilePushRectUniform,
+    &tilePullRect
+  },
+  {0, 0},
+  {0, 0, 0, 0}
+};
+
+void TiledView::drawRect(KDRect rect) const {
+  sCurrentTile.pixels = tile();
+  sCurrentTile.size = tileSize();
+
+  sTileContext.clippingRect.origin = KDPointZero; // Useless
+  sTileContext.clippingRect.size = sCurrentTile.size;
+
+  KDRect tileRect;
+  for (int i=0; i<(rect.width/sCurrentTile.size.width+1); i++) {
+    for (int j=0; j<(rect.height/sCurrentTile.size.height+1); j++) {
+      tileRect.x = rect.x + i*sCurrentTile.size.width;
+      tileRect.y = rect.y + j*sCurrentTile.size.height;
+      tileRect.size = sCurrentTile.size;
+      //tileRect = KDRectIntersection(tileRect, rect); // Optional
+      KDContext * previousContext = KDCurrentContext;
+      sTileContext.origin.x = -tileRect.x;
+      sTileContext.origin.y = -tileRect.y;
+
+      KDCurrentContext = &sTileContext;
+      drawTile(tileRect);
+      KDCurrentContext = previousContext;
+      KDSize zero = {0,0};
+
+      KDFillRectWithPixels(tileRect, sCurrentTile.pixels, sCurrentTile.pixels);
+    }
+  }
+}
diff --git a/ion/include/ion/screen.h b/ion/include/ion/screen.h
index c00e26029..6ad92ba2d 100644
--- a/ion/include/ion/screen.h
+++ b/ion/include/ion/screen.h
@@ -11,21 +11,16 @@
  * pixel coordinates every time. We're therefore leveraging this capability
  * which results in a very consequent speedup (up to ~10x faster). */
 
-#include <stdint.h>
-#include <stddef.h>
+#include <kandinsky.h>
 
-/* ION manipulates RGB565 colors */
-typedef uint16_t ion_color_t;
-
-/* Set the color of a single pixel. */
-void ion_set_pixel(uint16_t x, uint16_t y, ion_color_t color);
-
-/* Fill a rect with a single color */
-void ion_fill_rect(
-    uint16_t x, uint16_t y,
-    uint16_t width, uint16_t height,
-    ion_color_t * pattern, size_t patternSize
-);
+void ion_screen_push_rect(KDRect rect, const KDColor * pixels);
+void ion_screen_push_rect_uniform(KDRect rect, KDColor color);
+void ion_screen_pull_rect(KDRect rect, KDColor * pixels);
+/*
+void ion_screen_set_working_area(KDRect area);
+void ion_screen_push_pixels(const KDColor * pixels, size_t count);
+void ion_screen_pull_pixels(KDColor * pixels, size_t count);
+*/
 
 #define ION_SCREEN_WIDTH 320
 #define ION_SCREEN_HEIGHT 240
diff --git a/ion/src/device/display/display.c b/ion/src/device/display/display.c
index a53f6bc2d..d59bf0206 100644
--- a/ion/src/device/display/display.c
+++ b/ion/src/device/display/display.c
@@ -40,25 +40,59 @@ void ion_display_off() {
   // Turn off panel
 }
 
-void ion_set_pixel(uint16_t x, uint16_t y, ion_color_t color) {
-  st7789_set_drawing_area(&sDisplayController, x, y, 1, 1);
-  st7789_push_pixels(&sDisplayController, &color, 1);
+void ion_screen_push_rect(KDRect rect, const KDColor * pixels) {
+  st7789_set_drawing_area(&sDisplayController, rect);
+  st7789_push_pixels(&sDisplayController, pixels, rect.width*rect.height);
 }
 
-void ion_fill_rect(
-    uint16_t x, uint16_t y,
-    uint16_t width, uint16_t height,
-    ion_color_t * pattern, size_t patternSize)
-{
-  st7789_set_drawing_area(&sDisplayController, x, y, width, height);
-  size_t remainingSize = width*height;
-  while (remainingSize > 0) {
-    int32_t blockSize = remainingSize > patternSize ? patternSize : remainingSize;
-    st7789_push_pixels(&sDisplayController, pattern, blockSize);
-    remainingSize -= blockSize;
+void ion_screen_push_rect_uniform(KDRect rect, KDColor color) {
+  st7789_set_drawing_area(&sDisplayController, rect);
+  for (size_t i=0; i<rect.width*rect.height; i++) {
+    st7789_push_pixels(&sDisplayController, &color, 1);
   }
 }
 
+void ion_screen_pull_rect(KDRect rect, KDColor * pixels) {
+  assert(0); // Unimplemented
+}
+
+#if 0
+void ion_screen_push_rect(
+    uint16_t x, uint16_t y,
+    uint16_t width, uint16_t height,
+    ion_color_t * pattern, uint16_t patternWidth, uint16_t patternHeight)
+{
+  st7789_set_drawing_area(&sDisplayController, x, y, width, height);
+#if ION_DEVICE_FILL_RECT_FAST_PATH
+  /* If the pattern width matches the target rect width, we can easily push
+   * mutliple lines at once since those will be contiguous in memory. */
+  if (patternWidth == width) {
+    size_t remainingSize = width*height;
+    size_t patternSize = patternWidth*patternHeight;
+    while (remainingSize > 0) {
+      int32_t blockSize = remainingSize > patternSize ? patternSize : remainingSize;
+      st7789_push_pixels(&sDisplayController, pattern, blockSize);
+      remainingSize -= blockSize;
+    }
+    return;
+  }
+#endif
+  uint16_t remainingHeight = height;
+  uint16_t patternLine = 0;
+  while (remainingHeight-- > 0) {
+    uint16_t remainingWidth = width;
+    while (remainingWidth > 0) {
+      int32_t blockSize = remainingWidth > patternWidth ? patternWidth : remainingWidth;
+      st7789_push_pixels(&sDisplayController, pattern+patternLine*patternWidth, blockSize);
+      remainingWidth -= blockSize;
+    }
+    if (++patternLine >= patternHeight) {
+      patternLine = 0;
+    }
+  }
+}
+#endif
+
 void init_display() {
   //assert(FRAMEBUFFER_LENGTH == (FRAMEBUFFER_WIDTH*FRAMEBUFFER_HEIGHT*FRAMEBUFFER_BITS_PER_PIXEL)/8);
 
diff --git a/ion/src/device/display/st7789.c b/ion/src/device/display/st7789.c
index ecf9b50c7..1b1c5d3f5 100644
--- a/ion/src/device/display/st7789.c
+++ b/ion/src/device/display/st7789.c
@@ -155,11 +155,12 @@ void st7789_initialize(st7789_t * c) {
   perform_instructions(c, init_sequence, sizeof(init_sequence)/sizeof(init_sequence[0]));
 }
 
-void st7789_set_drawing_area(st7789_t * controller, int16_t x, int16_t y, int16_t width, int16_t height) {
-  uint16_t x_start = x;
-  uint16_t x_end = x + width - 1;
-  uint16_t y_start = y;
-  uint16_t y_end = y + height - 1;
+void st7789_set_drawing_area(st7789_t * controller, KDRect area) {
+  assert(sizeof(KDCoordinate) == 2); // We expect 16-bit values
+  uint16_t x_start = area.x;
+  uint16_t x_end = area.x + area.width - 1;
+  uint16_t y_start = area.y;
+  uint16_t y_end = area.y + area.height - 1;
 
   const instruction_t sequence[] = {
     COMMAND(CASET),
@@ -180,8 +181,11 @@ void st7789_set_drawing_area(st7789_t * controller, int16_t x, int16_t y, int16_
   perform_instructions(controller, sequence, sizeof(sequence)/sizeof(sequence[0]));
 }
 
-void st7789_push_pixels(st7789_t * controller, ion_color_t * pixels, int32_t numberOfPixels) {
-  for (int32_t i=0; i<numberOfPixels; i++) {
+
+void st7789_push_pixels(st7789_t * controller,
+    const KDColor * pixels, size_t numberOfPixels) {
+  assert(sizeof(KDColor) == 2); // We expect KDColor to be RGB565
+  for (size_t i=0; i<numberOfPixels; i++) {
     perform_instruction(controller, DATA(pixels[i] >> 8));
     perform_instruction(controller, DATA(pixels[i] & 0xFF));
   }
diff --git a/ion/src/device/display/st7789.h b/ion/src/device/display/st7789.h
index 360b451d7..a35ff75ef 100644
--- a/ion/src/device/display/st7789.h
+++ b/ion/src/device/display/st7789.h
@@ -5,6 +5,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <ion/screen.h>
+#include <kandinsky.h>
 
 #define ST7789_USE_9BIT_SPI 1
 
@@ -22,10 +23,8 @@ typedef struct {
 
 void st7789_initialize(st7789_t * controller);
 
-void st7789_set_drawing_area(st7789_t * controller,
-    int16_t x, int16_t y,
-    int16_t width, int16_t height);
+void st7789_set_drawing_area(st7789_t * controller, KDRect area);
 
 void st7789_push_pixels(st7789_t * controller,
-    ion_color_t * pixels, int32_t numberOfPixels);
+    const KDColor * pixels, size_t numberOfPixels);
 #endif
diff --git a/ion/src/simulator/display/fltklcd.cpp b/ion/src/simulator/display/fltklcd.cpp
index 28e242f85..834f60475 100644
--- a/ion/src/simulator/display/fltklcd.cpp
+++ b/ion/src/simulator/display/fltklcd.cpp
@@ -2,14 +2,32 @@
 #include <stdlib.h>
 #include <FL/fl_draw.H>
 
-FltkLCD::FltkLCD(int x, int y, int w, int h, const char * label) :
-  Fl_Widget(x, y, w, h, label) {
-  m_framebuffer = malloc(w*h*3);
-// FIXME: Delete the framebuffer!
+FltkLCD::FltkLCD(int x, int y, int w, int h, uint16_t * rgb565FrameBuffer) :
+  Fl_Widget(x, y, w, h, nullptr),
+  m_rgb565frameBufferStart(rgb565FrameBuffer),
+  m_rgb565frameBufferEnd(rgb565FrameBuffer+w*h)
+{
+  m_rgb888frameBufferStart = malloc(w*h*3);
+}
+
+FltkLCD::~FltkLCD() {
+  free(m_rgb888frameBufferStart);
 }
 
 void FltkLCD::draw() {
-  fl_draw_image((const uchar *)m_framebuffer,
+  // 1/ Convert the framebuffer from 565 to 888
+  KDColor * rgb565Pixel = m_rgb565frameBufferStart;
+  uint8_t * rgb888Component = (uint8_t *)m_rgb888frameBufferStart;
+
+  while(rgb565Pixel < m_rgb565frameBufferEnd) {
+    KDColor color = *rgb565Pixel++;
+    *rgb888Component++ = KDColorRedComponent(color);
+    *rgb888Component++ = KDColorGreenComponent(color);
+    *rgb888Component++ = KDColorBlueComponent(color);
+  }
+
+  // 2/ Draw the 888 framebuffer
+  fl_draw_image((const uchar *)m_rgb888frameBufferStart,
       x(), // x
       y(), // y
       w(), // width
diff --git a/ion/src/simulator/display/fltklcd.h b/ion/src/simulator/display/fltklcd.h
index 451c28d4d..f231f5b49 100644
--- a/ion/src/simulator/display/fltklcd.h
+++ b/ion/src/simulator/display/fltklcd.h
@@ -2,13 +2,18 @@
 #define ION_FLTK_LCD
 
 #include <FL/Fl_Widget.H>
+#include <kandinsky.h>
 
 class FltkLCD : public Fl_Widget {
   public:
-    FltkLCD(int x, int y, int w, int h, const char * label = 0);
-    void * m_framebuffer;
+    FltkLCD(int x, int y, int w, int h, KDColor * rgb565FrameBuffer);
+    ~FltkLCD();
   protected:
     void draw();
+  private:
+    KDColor * m_rgb565frameBufferStart;
+    KDColor * m_rgb565frameBufferEnd;
+    void * m_rgb888frameBufferStart;
 };
 
 #endif
diff --git a/ion/src/simulator/init.cpp b/ion/src/simulator/init.cpp
index 1645b6f5b..38831f836 100644
--- a/ion/src/simulator/init.cpp
+++ b/ion/src/simulator/init.cpp
@@ -15,6 +15,7 @@ extern "C" {
 
 static FltkLCD * sDisplay;
 static FltkKbd * sKeyboard;
+static KDFrameBuffer sFrameBuffer;
 
 #define FRAMEBUFFER_ADDRESS (sDisplay->m_framebuffer)
 
@@ -28,34 +29,34 @@ void init_platform() {
 
   Fl_Window * window = new Fl_Window(screen_width+2*margin, margin+screen_height+margin+keyboard_height+margin);
 
-  sDisplay = new FltkLCD(margin, margin, screen_width, screen_height);
+  sFrameBuffer.pixels = (KDColor *)malloc(ION_SCREEN_WIDTH*ION_SCREEN_HEIGHT*2);
+  sFrameBuffer.size.width = ION_SCREEN_WIDTH;
+  sFrameBuffer.size.height = ION_SCREEN_HEIGHT;
+  /*
+  sFrameBuffer.drawingArea.origin = KDPointZero;
+  sFrameBuffer.drawingArea.size = sFrameBuffer.size;
+  sFrameBuffer.drawingCursor = KDPointZero;
+  */
 
+  sDisplay = new FltkLCD(margin, margin, screen_width, screen_height, sFrameBuffer.pixels);
   sKeyboard = new FltkKbd(margin, margin+screen_height+margin, screen_width, keyboard_height);
 
   window->end();
   window->show();
 
-  KDCurrentContext->fillRect = NULL;
+  //KDCurrentContext->fillRect = NULL;
 }
 
-void ion_set_pixel(uint16_t x, uint16_t y, ion_color_t color) {
-  assert(x < ION_SCREEN_WIDTH);
-  assert(y < ION_SCREEN_HEIGHT);
-  uint8_t * pixel = (uint8_t *)(FRAMEBUFFER_ADDRESS) + 3*((y*ION_SCREEN_WIDTH)+x);
-  uint8_t red = (color >> 11) << 3;
-  uint8_t green = ((color >> 5) & 0x3F) << 2;
-  uint8_t blue = (color & 0x1F) << 3;
-  *pixel++ = red;
-  *pixel++ = green;
-  *pixel++ = blue;
+void ion_screen_push_rect(KDRect rect, const KDColor * pixels) {
+  KDFramePushRect(&sFrameBuffer, rect, pixels);
 }
 
-void ion_fill_rect(
-    uint16_t x, uint16_t y,
-    uint16_t width, uint16_t height,
-    ion_color_t * pattern, size_t patternSize)
-{
-  assert(false);
+void ion_screen_push_rect_uniform(KDRect rect, KDColor color) {
+  KDFramePushRectUniform(&sFrameBuffer, rect, color);
+}
+
+void ion_screen_pull_rect(KDRect rect, KDColor * pixels) {
+  KDFramePullRect(&sFrameBuffer, rect, pixels);
 }
 
 bool ion_key_down(ion_key_t key) {
diff --git a/kandinsky/Makefile b/kandinsky/Makefile
index c361f6fe0..a9cfd3593 100644
--- a/kandinsky/Makefile
+++ b/kandinsky/Makefile
@@ -1,7 +1,9 @@
 SFLAGS += -Ikandinsky/include
 objs += $(addprefix kandinsky/src/,\
+  color.o\
   context.o\
   font.o\
+  framebuffer.o\
   line.o\
   pixel.o\
   rect.o\
diff --git a/kandinsky/include/kandinsky.h b/kandinsky/include/kandinsky.h
index b3c7d5abe..e99ceeb2e 100644
--- a/kandinsky/include/kandinsky.h
+++ b/kandinsky/include/kandinsky.h
@@ -3,6 +3,7 @@
 
 #include <kandinsky/color.h>
 #include <kandinsky/context.h>
+#include <kandinsky/framebuffer.h>
 #include <kandinsky/line.h>
 #include <kandinsky/pixel.h>
 #include <kandinsky/rect.h>
diff --git a/kandinsky/include/kandinsky/color.h b/kandinsky/include/kandinsky/color.h
index df47877ca..9b8c1e6b4 100644
--- a/kandinsky/include/kandinsky/color.h
+++ b/kandinsky/include/kandinsky/color.h
@@ -11,8 +11,13 @@ typedef uint16_t KDColor;
  * Given KDColor is RGB565 and that we take 8-bit values for R, G, and B,
  * some shifting has to happen. */
 
+// FIXME: KDColorRGB(rgb), as a single 32-bits value
 #define KDColorRGB(r,g,b) ((KDColor)((((((uint16_t)(r))>>3)&0x1F)<<11)|(((((uint16_t)(g))>>2)&0x3F)<<5)|((((uint16_t)(b))>>3)&0x1F)))
 
+#define KDColorRedComponent(color) ((uint8_t)(((color)>>11)<<3))
+#define KDColorGreenComponent(color) ((uint8_t)((((color)>>5)&0x3F)<<2))
+#define KDColorBlueComponent(color) ((uint8_t)(((color)&0x1F)<<3))
+
 #define KDColorGray(i) KDColorRGB(i,i,i)
 
 #define KDColorBlack KDColorRGB(0x00, 0x00, 0x00)
@@ -22,4 +27,8 @@ typedef uint16_t KDColor;
 #define KDColorGreen KDColorRGB(0x00, 0xFF, 0x00)
 #define KDColorBlue KDColorRGB(0x00, 0x00, 0xFF)
 
+// alpha = 0 -> only a
+// alpha = 0xFF -> only b
+KDColor KDColorBlend(KDColor background, KDColor foreground, uint8_t alpha);
+
 #endif
diff --git a/kandinsky/include/kandinsky/context.h b/kandinsky/include/kandinsky/context.h
index 7780a2c4d..4d3716c85 100644
--- a/kandinsky/include/kandinsky/context.h
+++ b/kandinsky/include/kandinsky/context.h
@@ -5,12 +5,11 @@
 #include "rect.h"
 
 typedef struct {
-  void (*setPixel)(KDCoordinate x, KDCoordinate y, KDColor color);
-  // fillRect can be left NULL.
-  // In that case, Kandinsky will fall back to using setPixel only
-  void (*fillRect)(KDCoordinate x, KDCoordinate y,
-      KDCoordinate width, KDCoordinate height,
-      KDColor * pattern, size_t patternSize);
+  struct {
+    void (*pushRect)(KDRect rect, const KDColor * pixels);
+    void (*pushRectUniform)(KDRect rect, KDColor color);
+    void (*pullRect)(KDRect rect, KDColor * pixels);
+  } io;
   KDPoint origin;
   KDRect clippingRect;
 } KDContext;
diff --git a/kandinsky/include/kandinsky/framebuffer.h b/kandinsky/include/kandinsky/framebuffer.h
new file mode 100644
index 000000000..04335ff2c
--- /dev/null
+++ b/kandinsky/include/kandinsky/framebuffer.h
@@ -0,0 +1,17 @@
+#ifndef KANDINSKY_FRAMEBUFFER_H
+#define KANDINSKY_FRAMEBUFFER_H
+
+#include <kandinsky/color.h>
+#include <kandinsky/types.h>
+#include <kandinsky/rect.h>
+
+typedef struct {
+  KDColor * pixels;
+  KDSize size;
+} KDFrameBuffer;
+
+void KDFramePushRect(KDFrameBuffer * frameBuffer, KDRect rect, const KDColor * pixels);
+void KDFramePushRectUniform(KDFrameBuffer * frameBuffer, KDRect rect, KDColor color);
+void KDFramePullRect(KDFrameBuffer * frameBuffer, KDRect rect, KDColor * pixels);
+
+#endif
diff --git a/kandinsky/include/kandinsky/line.h b/kandinsky/include/kandinsky/line.h
index 069c1e0ac..7affd543e 100644
--- a/kandinsky/include/kandinsky/line.h
+++ b/kandinsky/include/kandinsky/line.h
@@ -6,4 +6,6 @@
 
 void KDDrawLine(KDPoint p1, KDPoint p2, KDColor c);
 
+void KDDrawAntiAliasedLine(KDPoint p1, KDPoint p2, KDCoordinate width, KDColor frontColor, KDColor backColor);
+
 #endif
diff --git a/kandinsky/include/kandinsky/pixel.h b/kandinsky/include/kandinsky/pixel.h
index d3e3a045d..f12762880 100644
--- a/kandinsky/include/kandinsky/pixel.h
+++ b/kandinsky/include/kandinsky/pixel.h
@@ -5,5 +5,6 @@
 #include <kandinsky/color.h>
 
 void KDSetPixel(KDPoint p, KDColor c);
+KDColor KDGetPixel(KDPoint p);
 
 #endif
diff --git a/kandinsky/include/kandinsky/rect.h b/kandinsky/include/kandinsky/rect.h
index a77118359..922e9f170 100644
--- a/kandinsky/include/kandinsky/rect.h
+++ b/kandinsky/include/kandinsky/rect.h
@@ -34,7 +34,9 @@ KDRect KDRectUnion(KDRect r1, KDRect r2);
 bool KDRectContains(KDRect r, KDPoint p);
 KDRect KDRectTranslate(KDRect r, KDPoint p);
 
-void KDFillRect(KDRect rect, const KDColor * pattern, size_t patternSize);
+void KDFillRect(KDRect rect, KDColor color);
+void KDFillRectWithPixels(KDRect rect, const KDColor * pixels, KDColor * workingBuffer);
+void KDFillRectWithMask(KDRect rect, KDColor color, const uint8_t * mask, KDColor * workingBuffer);
 void KDDrawRect(KDRect rect, KDColor color);
 
 #endif
diff --git a/kandinsky/src/color.c b/kandinsky/src/color.c
new file mode 100644
index 000000000..890bc89cb
--- /dev/null
+++ b/kandinsky/src/color.c
@@ -0,0 +1,11 @@
+#include <kandinsky/color.h>
+
+#define KDAlphaBlend(c1,c2,a) ((uint8_t)((((uint16_t)c1*(0xFF-a))+((uint16_t)c2*a))/0xFF))
+
+KDColor KDColorBlend(KDColor a, KDColor b, uint8_t alpha) {
+  return KDColorRGB(
+      KDAlphaBlend(KDColorRedComponent(a), KDColorRedComponent(b), alpha),
+      KDAlphaBlend(KDColorGreenComponent(a), KDColorGreenComponent(b), alpha),
+      KDAlphaBlend(KDColorBlueComponent(a), KDColorBlueComponent(b), alpha)
+      );
+}
diff --git a/kandinsky/src/context.c b/kandinsky/src/context.c
index f9303b77b..9e42c2b1f 100644
--- a/kandinsky/src/context.c
+++ b/kandinsky/src/context.c
@@ -2,8 +2,11 @@
 #include <ion.h>
 
 KDContext KDIonContext = {
-  .setPixel = &ion_set_pixel,
-  .fillRect = &ion_fill_rect,
+  .io = {
+    .pushRect = &ion_screen_push_rect,
+    .pushRectUniform = &ion_screen_push_rect_uniform,
+    .pullRect = &ion_screen_pull_rect
+  },
   .origin = {
     .x = 0,
     .y = 0
diff --git a/kandinsky/src/framebuffer.c b/kandinsky/src/framebuffer.c
new file mode 100644
index 000000000..b4d77feb5
--- /dev/null
+++ b/kandinsky/src/framebuffer.c
@@ -0,0 +1,34 @@
+#include <kandinsky/framebuffer.h>
+#include <string.h>
+
+static inline KDColor * frameBufferPixelAddress(KDFrameBuffer * frameBuffer, KDCoordinate x, KDCoordinate y) {
+    return frameBuffer->pixels + x + y*frameBuffer->size.width;
+}
+
+void KDFramePushRect(KDFrameBuffer * frameBuffer, KDRect rect, const KDColor * pixels) {
+  const KDColor * line = pixels;
+  for (int j=0; j<rect.height; j++) {
+    memcpy(frameBufferPixelAddress(frameBuffer, rect.x, rect.y+j),
+        line,
+        rect.width*sizeof(KDColor));
+    line += rect.width;
+  }
+}
+
+void KDFramePushRectUniform(KDFrameBuffer * frameBuffer, KDRect rect, KDColor color) {
+  for (int j=0; j<rect.height; j++) {
+    for (int i=0; i<rect.width; i++) {
+      *frameBufferPixelAddress(frameBuffer, rect.x+i, rect.y+j) = color;
+    }
+  }
+}
+
+void KDFramePullRect(KDFrameBuffer * frameBuffer, KDRect rect, KDColor * pixels) {
+  KDColor * line = pixels;
+  for (int j=0; j<rect.height; j++) {
+    memcpy(line,
+        frameBufferPixelAddress(frameBuffer, rect.x, rect.y+j),
+        rect.width*sizeof(KDColor));
+    line += rect.width;
+  }
+}
diff --git a/kandinsky/src/line.c b/kandinsky/src/line.c
index 1deb9dd6b..6a6b728e1 100644
--- a/kandinsky/src/line.c
+++ b/kandinsky/src/line.c
@@ -58,3 +58,43 @@ void KDDrawLine(KDPoint p1, KDPoint p2, KDColor c) {
     }
   }
 }
+/*
+#include <math.h>
+#include <stdlib.h>
+
+void KDDrawAntiAliasedLine(KDPoint p1, KDPoint p2, KDCoordinate width, KDColor frontColor, KDColor backColor) {
+  int x0 = p1.x;
+  int y0 = p1.y;
+  int x1 = p2.x;
+  int y1 = p2.y;
+  float wd = width;
+
+  int dx = abs(x1-x0), sx = x0 < x1 ? 1 : -1;
+  int dy = abs(y1-y0), sy = y0 < y1 ? 1 : -1;
+  int err = dx-dy, e2, x2, y2; // error value e_xy
+  float ed = dx+dy == 0 ? 1 : sqrt((float)dx*dx+(float)dy*dy);
+
+  for (wd = (wd+1)/2; ; ) { // pixel loop
+    KDPoint p = {.x = x0, .y = y0};
+    KDColor color = KDColorMix(KDColorRed, KDColorWhite, (abs(err-dx+dy)/ed-wd+1));
+    KDSetPixel(p, color);
+    e2 = err; x2 = x0;
+    if (2*e2 >= -dx) { // x step
+      for (e2 += dy, y2 = y0; e2 < ed*wd && (y1 != y2 || dx > dy); e2 += dx) {
+        y2 += sy;
+        p = {.x = x0, .y = y2};
+        color = KDColorMix(KDColorRed, KDColorWhite, (abs(err-dx+dy)/ed-wd+1));
+        setPixelColor(x0, y2 += sy, max(0,255*(abs(e2)/ed-wd+1)));
+      }
+      if (x0 == x1) break;
+      e2 = err; err -= dy; x0 += sx;
+    }
+    if (2*e2 <= dy) { // y step
+      for (e2 = dx-e2; e2 < ed*wd && (x1 != x2 || dx < dy); e2 += dy)
+        setPixelColor(x2 += sx, y0, max(0,255*(abs(e2)/ed-wd+1)));
+      if (y0 == y1) break;
+      err += dx; y0 += sy;
+    }
+  }
+}
+*/
diff --git a/kandinsky/src/pixel.c b/kandinsky/src/pixel.c
index 76198b31a..d162ce0e9 100644
--- a/kandinsky/src/pixel.c
+++ b/kandinsky/src/pixel.c
@@ -7,6 +7,29 @@
 void KDSetPixel(KDPoint p, KDColor c) {
   KDPoint absolutePoint = KDPointTranslate(p, KDCurrentContext->origin);
   if (KDRectContains(KDCurrentContext->clippingRect, absolutePoint)) {
-    KDCurrentContext->setPixel(absolutePoint.x, absolutePoint.y, c);
+    KDCurrentContext->io.pushRect((KDRect){.origin = absolutePoint, .width = 1, .height = 1}, &c);
   }
 }
+
+KDColor KDGetPixel(KDPoint p) {
+  KDPoint absolutePoint = KDPointTranslate(p, KDCurrentContext->origin);
+  if (KDRectContains(KDCurrentContext->clippingRect, absolutePoint)) {
+    KDColor result;
+    KDCurrentContext->io.pullRect((KDRect){.origin = absolutePoint, .width = 1, .height = 1}, &result);
+    return result;
+  }
+  return KDColorBlack;
+}
+/*
+void KDSetAbsolutePixelDirect(KDPoint p, KDColor c) {
+  KDCurrentContext->io.setWorkingArea((KDRect){.origin = p, .width = 1, .height = 1});
+  KDCurrentContext->io.pushPixels(&c, 1);
+}
+
+KDColor KDGetAbsolutePixelDirect(KDPoint p) {
+  KDColor result;
+  KDCurrentContext->io.setWorkingArea((KDRect){.origin = p, .width = 1, .height = 1});
+  KDCurrentContext->io.pullPixels(&result, 1);
+  return result;
+}
+*/
diff --git a/kandinsky/src/rect.c b/kandinsky/src/rect.c
index dfe2ab72c..ef4b64e6a 100644
--- a/kandinsky/src/rect.c
+++ b/kandinsky/src/rect.c
@@ -101,38 +101,150 @@ KDRect KDRectTranslate(KDRect r, KDPoint p) {
   };
 }
 
-void KDPerPixelFillRect(KDCoordinate x, KDCoordinate y,
-    KDCoordinate width, KDCoordinate height,
-    KDColor * pattern, size_t patternSize) {
-  size_t offset = 0;
-  for (KDCoordinate j=0; j<height; j++) {
-    for (KDCoordinate i=0; i<width; i++) {
-      KDCurrentContext->setPixel(x+i, y+j, pattern[offset++]);
-      if (offset >= patternSize) {
-        offset = 0;
-      }
+KDRect absoluteFillRect(KDRect rect) {
+  KDRect absolutRect = rect;
+  absolutRect.origin = KDPointTranslate(absolutRect.origin, KDCurrentContext->origin);
+
+  KDRect rectToBeFilled = KDRectIntersection(absolutRect, KDCurrentContext->clippingRect);
+  return rectToBeFilled;
+}
+
+void KDFillRect(KDRect rect, KDColor color) {
+  KDRect absoluteRect = absoluteFillRect(rect);
+  if (absoluteRect.width > 0 && absoluteRect.height > 0) {
+    KDCurrentContext->io.pushRectUniform(absoluteRect, color);
+  }
+}
+
+/* Note: we support the case where workingBuffer IS equal to pixels */
+void KDFillRectWithPixels(KDRect rect, const KDColor * pixels, KDColor * workingBuffer) {
+  KDRect absoluteRect = absoluteFillRect(rect);
+
+  if (absoluteRect.width == 0 || absoluteRect.height == 0) {
+    return;
+  }
+
+  /* Caution:
+   * The absoluteRect may have a SMALLER size than the original rect because it
+   * has been clipped. Therefore we cannot assume that the mask can be read as a
+   * continuous area. */
+
+  if (absoluteRect.width == rect.width && absoluteRect.height == rect.height) {
+    KDCurrentContext->io.pushRect(absoluteRect, pixels);
+    return;
+  }
+
+  /* At this point we need the working buffer */
+  assert(workingBuffer != NULL);
+  for (KDCoordinate j=0; j<absoluteRect.height; j++) {
+    for (KDCoordinate i=0; i<absoluteRect.width; i++) {
+      workingBuffer[i+absoluteRect.width*j] = pixels[i+rect.width*j];
+    }
+  }
+  KDCurrentContext->io.pushRect(absoluteRect, workingBuffer);
+}
+
+// Mask's size must be rect.size
+// WorkingBuffer, same deal
+void KDFillRectWithMask(KDRect rect, KDColor color, const uint8_t * mask, KDColor * workingBuffer) {
+  KDRect absoluteRect = absoluteFillRect(rect);
+
+  /* Caution:
+   * The absoluteRect may have a SMALLER size than the original rect because it
+   * has been clipped. Therefore we cannot assume that the mask can be read as a
+   * continuous area. */
+
+  KDCurrentContext->io.pullRect(absoluteRect, workingBuffer);
+  for (KDCoordinate j=0; j<absoluteRect.height; j++) {
+    for (KDCoordinate i=0; i<absoluteRect.width; i++) {
+      KDColor * currentPixelAdress = workingBuffer + i + absoluteRect.width*j;
+      const uint8_t * currentMaskAddress = mask + i + rect.width*j;
+      *currentPixelAdress = KDColorBlend(*currentPixelAdress, color, *currentMaskAddress);
+    }
+  }
+  KDCurrentContext->io.pushRect(absoluteRect, workingBuffer);
+}
+
+#if 0
+
+/* Takes an absolute rect and pushes the pixels */
+/* Does the pattern-to-continuous-memory conversion */
+void pushRect(KDRect rect, const KDColor * pattern, KDSize patternSize) {
+  KDCurrentContext->io.setWorkingArea(rect);
+//#define ION_DEVICE_FILL_RECT_FAST_PATH 1
+#if ION_DEVICE_FILL_RECT_FAST_PATH
+  /* If the pattern width matches the target rect width, we can easily push
+   * mutliple lines at once since those will be contiguous in memory. */
+  if (patternSize.width == rect.width) {
+    size_t remainingPixelCount = rect.width*rect.height;
+    size_t patternPixelCount = patternSize.width*patternSize.height;
+    while (remainingPixelCount > 0) {
+      int32_t blockSize = remainingPixelCount < patternPixelCount ? remainingPixelCount : patternPixelCount;
+      KDCurrentContext->io.pushPixels(pattern, blockSize);
+      remainingPixelCount -= blockSize;
+    }
+    return;
+  }
+#endif
+  uint16_t remainingHeight = rect.height;
+  uint16_t patternLine = 0;
+  while (remainingHeight-- > 0) {
+    uint16_t remainingWidth = rect.width;
+    while (remainingWidth > 0) {
+      int32_t blockSize = remainingWidth < patternSize.width ? remainingWidth : patternSize.width;
+      KDCurrentContext->io.pushPixels(pattern + patternLine*patternSize.width, blockSize);
+      remainingWidth -= blockSize;
+    }
+    if (++patternLine >= patternSize.height) {
+      patternLine = 0;
     }
   }
 }
 
-void KDFillRect(KDRect rect, const KDColor * pattern, size_t patternSize) {
-  assert(patternSize >= 1);
+void KDBlitRect(KDRect rect, const KDColor * pattern, KDSize patternSize, const uint8_t * mask, KDSize maskSize) {
+  assert(pattern != NULL && patternSize.width > 0 && patternSize.height > 0);
   KDRect absolutRect = rect;
   absolutRect.origin = KDPointTranslate(absolutRect.origin, KDCurrentContext->origin);
 
   KDRect rectToBeFilled = KDRectIntersection(absolutRect, KDCurrentContext->clippingRect);
 
-  void (*fillRectFunction)(KDCoordinate x, KDCoordinate y,
-      KDCoordinate width, KDCoordinate height,
-      KDColor * pattern, size_t patternSize) = KDCurrentContext->fillRect;
-  if (fillRectFunction == NULL) {
-    fillRectFunction = KDPerPixelFillRect;
+  bool useBlending = (mask != NULL && maskSize.width > 0 && maskSize.height > 0);
+
+  if (!useBlending) {
+    pushRect(rectToBeFilled, pattern, patternSize);
+    return;
   }
 
-  fillRectFunction(rectToBeFilled.x, rectToBeFilled.y,
-      rectToBeFilled.width, rectToBeFilled.height,
-      pattern, patternSize);
+  assert(KDCurrentContext->io.pullPixels != NULL);
+
+  KDCoordinate patternX = 0, patternY = 0, maskX = 0, maskY = 0;
+  for (KDCoordinate j=0; j<rectToBeFilled.height; j++) {
+    for (KDCoordinate i=0; i<rectToBeFilled.width; i++) {
+      KDColor foregroundColor = pattern[patternX+patternSize.width*patternY];
+      KDPoint p = {
+        .x = rectToBeFilled.x + i,
+        .y = rectToBeFilled.y + j
+      };
+      KDColor backgroundColor = KDGetAbsolutePixelDirect(p);
+      uint8_t alpha = mask[maskX+maskSize.width*maskY];
+      KDColor newColor = KDColorBlend(backgroundColor, foregroundColor, alpha);
+      KDSetAbsolutePixelDirect(p, newColor);
+      if (++patternX >= patternSize.width) {
+        patternX = 0;
+      }
+      if (++maskX >= maskSize.width) {
+        maskX = 0;
+      }
+    }
+    if (++patternY >= patternSize.height) {
+      patternY = 0;
+    }
+    if (++maskY >= maskSize.height) {
+      maskY = 0;
+    }
+  }
 }
+#endif
 
 void KDDrawRect(KDRect rect, KDColor color) {
   KDPoint p1, p2;
diff --git a/liba/Makefile b/liba/Makefile
index 427b1b432..db13011f5 100644
--- a/liba/Makefile
+++ b/liba/Makefile
@@ -4,3 +4,7 @@ liba/src/external/sqlite/mem5.o: CFLAGS += -w
 
 objs += $(addprefix liba/src/, assert.o errno.o malloc.o memcpy.o memset.o powf.o strcmp.o strlen.o external/sqlite/mem5.o)
 tests += $(addprefix liba/test/, stdint.c)
+
+# The use of aeabi-rt could be made conditional to an AEABI target.
+# In practice we're always using liba on such a target.
+objs += $(addprefix liba/src/aeabi-rt/, memcpy.o)
diff --git a/liba/src/aeabi-rt/README.txt b/liba/src/aeabi-rt/README.txt
new file mode 100644
index 000000000..be3109f12
--- /dev/null
+++ b/liba/src/aeabi-rt/README.txt
@@ -0,0 +1,16 @@
+We're using the ARM Embedded ABI (AEABI) to build our code for the Cortex-M.
+That ABI specifies a lot of things: how procedures are called, how ELF files
+should be structured, and last but not least, a run-time.
+
+That run-time consists in a list of helper functions that the compiler is free
+to call anywhere : unaligned memory accesses, integer division functions,
+memory copying/clearing/setting, etc...
+
+Since we're telling our compiler to build an AEABI binary, it may decide to use
+those symbols, and so we have to provide an implementation for them. Refer to
+the "Run-time ABI for the ARM Architecture" for a full list of functions.
+
+Note that this is not formally the job of a libc implementation. Similar code is
+often shipped alongside a compiler (LLVM calls it compiler-rt, GCC libgcc). But
+since we're using so few symbols in practice, it makes sense to glue it in. Also
+some libc do also implement this (newlib, for example).
diff --git a/liba/src/aeabi-rt/memcpy.c b/liba/src/aeabi-rt/memcpy.c
new file mode 100644
index 000000000..0b62598cc
--- /dev/null
+++ b/liba/src/aeabi-rt/memcpy.c
@@ -0,0 +1,8 @@
+#include <stddef.h>
+#include <string.h>
+
+/* See the "Run-time ABI for the ARM Architecture", Section 4.3.3 */
+
+void __aeabi_memcpy(void * dest, const void * src, size_t n) {
+  memcpy(dest, src, n);
+}