[rmkit] pack pixels into correct buffer format

src/dithering_demo/main.cpy

@@ -206,8 +206,8 @@ class App : public IApp:
       free(self.image.buffer)
     filename = string(IMAGES_DIR) + "/" + filename
     int channels
-    self.image.buffer = (uint32_t*)stbi_load(filename.c_str(), &self.image.w, &self.image.h, &channels, 1);
-    self.image.channels = 1
+    self.image.buffer = (uint32_t*)stbi_load(filename.c_str(), &self.image.w, &self.image.h, &channels, 4);
+    self.image.channels = 4
     util::resize_image(image, self.image.w, self.image.h, 0)
     undithered_bmp->image = self.image
     dithered_bmp->image = self.image

src/rmkit/color.h

@@ -31,6 +31,12 @@ struct rgb_color {
 // 0(black) - 31(white)
 constexpr remarkable_color gray32(int n)
 {
+
+    if (sizeof(remarkable_color) >= 3) {
+      n = (n * 0xff / 32);
+      return (n << 16) | (n << 8) | n;
+    }
+
     // The green channel should have six bits, but 31 is only five.
     // Set the last green bit unless n is zero
     // otherwise white is actually slightly pink
@@ -57,10 +63,17 @@ constexpr rgb_color to_rgb8(remarkable_color s)
 
 constexpr float to_float(remarkable_color c)
 {
+    if (sizeof(remarkable_color) >= 3) {
+      return ((c >> 16) & 0xff) * (0.21 / 0xff)  // red
+           + ((c >>  8) & 0xff) * (0.72 / 0xff)  // green
+           + ((c >>  0) & 0xff) * (0.07 / 0xff); // blue
+    }
+
     // 0.21 R + 0.72 G + 0.07 B
     return ((c >> 11) & 31) * (0.21 / 31)  // red
          + ((c >> 5)  & 63) * (0.72 / 63)  // green
          + (c         & 31) * (0.07 / 31); // blue
+
 }
 
 // 16-gray palette (BLACK, WHITE, and 14 shades of gray)

src/rmkit/fb/fb.cpy

@@ -295,15 +295,20 @@ namespace framebuffer:
 
           do_dithering(self.fbmem, i+o_x, j+o_y, color, dither)
 
-    inline remarkable_color to_rgb565(char *src, int offset):
-        r := src[offset]
-        g := src[offset+1]
-        b := src[offset+2]
-        return (remarkable_color) (
-          ((r & 0b11111000) << 8) |
-          ((g & 0b11111100) << 3) |
-          ((b & 0b11111000) >> 3)
-        );
+    inline remarkable_color pack_pixel(char *src, int offset):
+      #ifdef RMKIT_FBINK
+      r := src[offset]
+      g := src[offset+1]
+      b := src[offset+2]
+      uint32_t out
+      fbink_pack_pixel_rgba(r, g, b, 0xff, &out)
+      return (remarkable_color) out
+      #else
+      r := src[offset]
+      g := src[offset+1]
+      b := src[offset+2]
+      return (remarkable_color) (((r >> 3U) << 11U) | ((g >> 2U) << 5U) | (b >> 3U));
+      #endif
 
     inline void grayscale_to_rgb32(uint8_t src, char *dst):
         uint32_t color = (src * 0x00010101);
@@ -349,12 +354,12 @@ namespace framebuffer:
             if image.channels == 4 && alpha:
               // 4th bit is alpha -- if it's 0, skip drawing
               if ((char*)src)[i*image.channels+3] != 0:
-                self._set_pixel(&ptr[i], i, j, to_rgb565((char *) src, i*image.channels))
+                self._set_pixel(&ptr[i], i, j, pack_pixel((char *) src, i*image.channels))
             else if image.channels >= 3:
-              self._set_pixel(&ptr[i], i, j, to_rgb565((char *) src, i*image.channels))
+              self._set_pixel(&ptr[i], i, j, pack_pixel((char *) src, i*image.channels))
             else if image.channels == 1:
               grayscale_to_rgb32(src[i], src_val)
-              self._set_pixel(&ptr[i], i, j, to_rgb565(src_val, 0))
+              self._set_pixel(&ptr[i], i, j, pack_pixel(src_val, 0))
             else:
               self._set_pixel(&ptr[i], i, j, src[i])