move the col/row offsets to the top so oleds can take advantage of em

ladyada · ladyada · commit b39dd8456000 · 2021-06-07T19:43:49.000-04:00
diff --git a/shared-module/displayio/display_core.c b/shared-module/displayio/display_core.c
@@ -216,10 +216,11 @@ void displayio_display_core_set_region_to_update(displayio_display_core_t *self,
     uint8_t row_command, uint16_t set_current_column_command, uint16_t set_current_row_command,
     bool data_as_commands, bool always_toggle_chip_select,
     displayio_area_t *area, bool SH1107_addressing) {
-    uint16_t x1 = area->x1;
-    uint16_t x2 = area->x2;
-    uint16_t y1 = area->y1;
-    uint16_t y2 = area->y2;
+    uint16_t x1 = area->x1 + self->colstart;
+    uint16_t x2 = area->x2 + self->colstart;
+    uint16_t y1 = area->y1 + self->rowstart;
+    uint16_t y2 = area->y2 + self->rowstart;
+
     // Collapse down the dimension where multiple pixels are in a byte.
     if (self->colorspace.depth < 8) {
         uint8_t pixels_per_byte = 8 / self->colorspace.depth;
@@ -232,6 +233,9 @@ void displayio_display_core_set_region_to_update(displayio_display_core_t *self,
         }
     }
 
+    x2 -= 1;
+    y2 -= 1;
+
     display_chip_select_behavior_t chip_select = CHIP_SELECT_UNTOUCHED;
     if (always_toggle_chip_select || data_as_commands) {
         chip_select = CHIP_SELECT_TOGGLE_EVERY_BYTE;
@@ -249,12 +253,11 @@ void displayio_display_core_set_region_to_update(displayio_display_core_t *self,
     } else {
         data_type = DISPLAY_COMMAND;
     }
+
     if (self->ram_width < 0x100) {
-        data[data_length++] = x1 + self->colstart;
-        data[data_length++] = x2 - 1 + self->colstart;
+        data[data_length++] = x1;
+        data[data_length++] = x2;
     } else {
-        x1 += self->colstart;
-        x2 += self->colstart - 1;
         data[data_length++] = x1 >> 8;
         data[data_length++] = x1 & 0xff;
         data[data_length++] = x2 >> 8;
@@ -289,12 +292,11 @@ void displayio_display_core_set_region_to_update(displayio_display_core_t *self,
         self->send(self->bus, DISPLAY_COMMAND, CHIP_SELECT_UNTOUCHED, data, 1);
         data_length = 0;
     }
+
     if (self->ram_height < 0x100) {
-        data[data_length++] = y1 + self->rowstart;
-        data[data_length++] = y2 - 1 + self->rowstart;
+        data[data_length++] = y1;
+        data[data_length++] = y2;
     } else {
-        y1 += self->rowstart;
-        y2 += self->rowstart - 1;
         data[data_length++] = y1 >> 8;
         data[data_length++] = y1 & 0xff;
         data[data_length++] = y2 >> 8;
