make packed word and copy it in

Author: caternuson

shared-module/displayio/Bitmap.c

@@ -173,29 +173,13 @@ void common_hal_displayio_bitmap_fill(displayio_bitmap_t *self, uint32_t value)
     self->dirty_area.y1 = 0;
     self->dirty_area.y2 = self->height;
 
-    // Update our data
-    int32_t row_start;
-    uint32_t bytes_per_value = self->bits_per_value / 8;
-    for (uint32_t x=0; x<self->width; x++) {
-        for (uint32_t y=0; y<self->height; y++) {
-            row_start = y * self->stride;
-            if (bytes_per_value < 1) {
-                uint32_t bit_position = (sizeof(size_t) * 8 - ((x & self->x_mask) + 1) * self->bits_per_value);
-                uint32_t index = row_start + (x >> self->x_shift);
-                uint32_t word = self->data[index];
-                word &= ~(self->bitmask << bit_position);
-                word |= (value & self->bitmask) << bit_position;
-                self->data[index] = word;
-            } else {
-                size_t* row = self->data + row_start;
-                if (bytes_per_value == 1) {
-                    ((uint8_t*) row)[x] = value;
-                } else if (bytes_per_value == 2) {
-                    ((uint16_t*) row)[x] = value;
-                } else if (bytes_per_value == 4) {
-                    ((uint32_t*) row)[x] = value;
-                }
-            }
-        }
+    // build the packed word
+    uint32_t word = 0;
+    for (uint8_t i=0; i<32 / self->bits_per_value; i++) {
+        word |= (value & self->bitmask) << (32 - ((i+1)*self->bits_per_value));
+    }
+    // copy it in
+    for (uint32_t i=0; i<self->stride * self->height; i++) {
+        self->data[i] = word;
     }
 }