boards: simulator: Add swipe detection and button support

Currently the simulator relies on the keyboard to issue touchscreen
gestures and button presses. Fix this by adding swipe detection and
introducing a skin which gives us the capability to press the button
using touchscreens or pointer devices.

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>

TODO.rst

@@ -144,3 +144,8 @@ Wasp-os
   * [ ] Debugging and troubleshooting guide
   * [ ] Screenshots for bootloader and all applications
   * [ ] Improve the install guide
+
+* [X] Simulator
+
+  * [X] Add a simple skin for better screenshots
+  * [X] Full swipe detection (avoid keyboard)

wasp/boards/simulator/display.py

@@ -14,6 +14,13 @@ RAMWR = 0x2c
 WIDTH = 240
 HEIGHT = 240
 
+SKIN = {
+    'fname' : 'res/simulator_skin.png',
+    'size' : (337, 427),
+    'button_profile' : 9,
+    'offset' : (53, 93)
+}
+
 class ST7789Sim(object):
     def __init__(self):
 
@@ -60,7 +67,9 @@ class ST7789Sim(object):
                          ((rgb & 0x07e0) << 5) +
                          ((rgb & 0x001f) << 3))
             
-                pixelview[self.x][self.y] = pixel
+                pv_x = self.x + SKIN['adjust'][0]
+                pv_y = self.y + SKIN['adjust'][1]
+                pixelview[pv_x][pv_y] = pixel
 
                 self.x += 1
                 if self.x > self.colclip[1]:
@@ -118,20 +127,61 @@ class CST816SSim():
         self.regs[3] = 0x80
         self.raise_interrupt(pins)
 
-    def handle_mousebutton(self, button, pins):
+    def handle_mousebuttondown(self, button, pins):
+        self.down_x = button.x
+        self.down_y = button.y
+
+        if self.down_x < 50:
+            pins['BUTTON'].value(0)
+
+
+    def handle_mousebuttonup(self, button, pins):
+        if self.down_x < 50:
+            pins['BUTTON'].value(1)
+            return
+
+        down_x = max(0, min(239, self.down_x-SKIN['adjust'][0]))
+        down_y = max(0, min(239, self.down_y-SKIN['adjust'][1]))
+        up_x = max(0, min(239, button.x-SKIN['adjust'][0]))
+        up_y = max(0, min(239, button.y-SKIN['adjust'][1]))
+        mv_x = up_x - down_x
+        mv_y = up_y - down_y
+
+        # Swipe detection
+        if abs(mv_x) + abs(mv_y) < 24:
             self.regs[1] = 5
-        self.regs[4] = button.x
-        self.regs[6] = button.y
+        elif abs(mv_x) > abs(mv_y):
+            self.regs[1] = 4 if mv_x > 0 else 3
+        else:
+            self.regs[1] = 2 if mv_y > 0 else 1
+
+        self.regs[4] = up_x;
+        self.regs[6] = up_y;
         self.raise_interrupt(pins)
 
     def raise_interrupt(self, pins):
         pins['TP_INT'].raise_irq()
 
+# Derive some extra values for padding the display
+SKIN['left_pad'] = 9
+SKIN['right_pad'] = SKIN['left_pad'] + SKIN['button_profile']
+SKIN['top_pad'] = 3
+SKIN['bottom_pad'] = 3
+SKIN['window'] = (SKIN['size'][0] + SKIN['left_pad'] + SKIN['right_pad'],
+                  SKIN['size'][1] + SKIN['top_pad'] + SKIN['bottom_pad'])
+SKIN['adjust'] = (SKIN['offset'][0] + SKIN['left_pad'],
+                  SKIN['offset'][1] + SKIN['top_pad'])
+
 sdl2.ext.init()
-window = sdl2.ext.Window("ST7789", size=(WIDTH, HEIGHT))
+window = sdl2.ext.Window("ST7789", size=SKIN['window'])
 window.show()
 windowsurface = window.get_surface()
-sdl2.ext.fill(windowsurface, (0, 0, 0))
+sdl2.ext.fill(windowsurface, (0xff, 0xff, 0xff))
+skin = sdl2.ext.load_image(SKIN['fname'])
+sdl2.SDL_BlitSurface(skin, None, windowsurface, sdl2.SDL_Rect(
+        SKIN['left_pad'], SKIN['top_pad'], SKIN['size'][0], SKIN['size'][1]))
+sdl2.SDL_FreeSurface(skin)
+window.refresh()
 
 spi_st7789_sim = ST7789Sim()
 i2c_cst816s_sim = CST816SSim()
@@ -143,7 +193,9 @@ def tick(pins):
             sdl2.ext.quit()
             sys.exit(0)
         elif event.type == sdl2.SDL_MOUSEBUTTONDOWN:
-            i2c_cst816s_sim.handle_mousebutton(event.button, pins)
+            i2c_cst816s_sim.handle_mousebuttondown(event.button, pins)
+        elif event.type == sdl2.SDL_MOUSEBUTTONUP:
+            i2c_cst816s_sim.handle_mousebuttonup(event.button, pins)
         elif event.type == sdl2.SDL_KEYDOWN:
             if event.key.keysym.sym == sdl2.SDLK_TAB:
                 pins['BUTTON'].value(0)