bitmaptools: Introduce new validators for coordinate pairs

Several of these routines use coordinate pairs, and jpeg decoding will
soon. Introduce a validator just for this use.

Author: jepler

shared-bindings/bitmaptools/__init__.c

@@ -43,6 +43,27 @@
 #include "extmod/vfs_posix.h"
 #endif
 
+// This assigns to [0] and [2] because the order is x1, y1, x2, y2
+STATIC void bitmaptools_validate_coord_range(int16_t out[3], const mp_arg_val_t in[3], int lim, const qstr what[2]) {
+    out[0] = mp_arg_validate_int_range(mp_arg_validate_type_int(in[0].u_obj, what[0]), 0, lim - 1, what[0]);
+    if (in[2].u_obj == mp_const_none) {
+        out[2] = lim;
+    } else {
+        out[2] = mp_arg_validate_int_range(mp_arg_validate_type_int(in[2].u_obj, what[1]), out[0] + 1, lim, what[1]);
+    }
+}
+
+bitmaptools_rect_t bitmaptools_validate_coord_range_pair(const mp_arg_val_t in[4], int width, int height) {
+    static const qstr x_names[] = {MP_QSTR_x1, MP_QSTR_x2};
+    static const qstr y_names[] = {MP_QSTR_y1, MP_QSTR_y2};
+
+    bitmaptools_rect_t rect;
+    bitmaptools_validate_coord_range(&rect.arr[0], in, width, x_names);
+    bitmaptools_validate_coord_range(&rect.arr[1], in + 1, height, y_names);
+    return rect;
+}
+
+
 //| """Collection of bitmap manipulation tools
 //|
 //| .. note:: If you're looking for information about displaying bitmaps on

shared-bindings/bitmaptools/__init__.h

@@ -32,6 +32,7 @@
 #include "shared-bindings/displayio/__init__.h"
 #include "shared-module/displayio/Palette.h"
 #include "py/obj.h"
+#include "py/runtime.h"
 #include "extmod/vfs_fat.h"
 
 typedef enum {
@@ -88,4 +89,21 @@ void common_hal_bitmaptools_dither(displayio_bitmap_t *dest_bitmap, displayio_bi
 void common_hal_bitmaptools_alphablend(displayio_bitmap_t *destination, displayio_bitmap_t *source1, displayio_bitmap_t *source2, displayio_colorspace_t colorspace, mp_float_t factor1, mp_float_t factor2,
     bitmaptools_blendmode_t blendmode, uint32_t skip_source1_index, bool skip_source1_index_none, uint32_t skip_source2_index, bool skip_source2_index_none);
 
+typedef struct {
+    union {
+        struct {
+            int16_t x1, y1, x2, y2;
+        };
+        int16_t arr[4];
+    };
+} bitmaptools_rect_t;
+
+#define ARGS_X1_Y1_X2_Y2 ARG_x1, ARG_y1, ARG_x2, ARG_y2
+#define ALLOWED_ARGS_X1_Y1_X2_Y2(if_required1, if_required2) \
+    {MP_QSTR_x1, if_required1 | MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0)}}, \
+    {MP_QSTR_y1, if_required2 | MP_ARG_OBJ, {.u_obj = MP_ROM_INT(0)}}, \
+    {MP_QSTR_x2, if_required1 | MP_ARG_OBJ, {.u_obj = MP_ROM_NONE}}, \
+    {MP_QSTR_y2, if_required2 | MP_ARG_OBJ, {.u_obj = MP_ROM_NONE}}
+
+bitmaptools_rect_t bitmaptools_validate_coord_range_pair(const mp_arg_val_t in[4], int width, int height);
 #endif // MICROPY_INCLUDED_SHARED_BINDINGS_BITMAPTOOLS__INIT__H