From 12ed7069615684b4dc8f8b9331c4a44aba52daa4 Mon Sep 17 00:00:00 2001
From: Phil Howard <github@gadgetoid.com>
Date: Wed, 11 Dec 2024 11:24:42 +0000
Subject: [PATCH] PicoVector: Add arbitrary matrix transform.

---
 micropython/modules/picovector/picovector.c   |  2 ++
 micropython/modules/picovector/picovector.cpp | 25 +++++++++++++++++++
 micropython/modules/picovector/picovector.h   |  1 +
 3 files changed, 28 insertions(+)

diff --git a/micropython/modules/picovector/picovector.c b/micropython/modules/picovector/picovector.c
index 1caaeeb11..7c6b1e482 100644
--- a/micropython/modules/picovector/picovector.c
+++ b/micropython/modules/picovector/picovector.c
@@ -62,12 +62,14 @@ MP_DEFINE_CONST_OBJ_TYPE(
 static MP_DEFINE_CONST_FUN_OBJ_3(TRANSFORM_rotate_obj, TRANSFORM_rotate);
 static MP_DEFINE_CONST_FUN_OBJ_3(TRANSFORM_translate_obj, TRANSFORM_translate);
 static MP_DEFINE_CONST_FUN_OBJ_3(TRANSFORM_scale_obj, TRANSFORM_scale);
+static MP_DEFINE_CONST_FUN_OBJ_2(TRANSFORM_custom_obj, TRANSFORM_custom);
 static MP_DEFINE_CONST_FUN_OBJ_1(TRANSFORM_reset_obj, TRANSFORM_reset);
 
 static const mp_rom_map_elem_t TRANSFORM_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_rotate), MP_ROM_PTR(&TRANSFORM_rotate_obj) },
     { MP_ROM_QSTR(MP_QSTR_translate), MP_ROM_PTR(&TRANSFORM_translate_obj) },
     { MP_ROM_QSTR(MP_QSTR_scale), MP_ROM_PTR(&TRANSFORM_scale_obj) },
+    { MP_ROM_QSTR(MP_QSTR_matrix), MP_ROM_PTR(&TRANSFORM_custom_obj) },
     { MP_ROM_QSTR(MP_QSTR_reset), MP_ROM_PTR(&TRANSFORM_reset_obj) },
 };
 
diff --git a/micropython/modules/picovector/picovector.cpp b/micropython/modules/picovector/picovector.cpp
index a920f6ad5..c6f603b41 100644
--- a/micropython/modules/picovector/picovector.cpp
+++ b/micropython/modules/picovector/picovector.cpp
@@ -544,6 +544,31 @@ mp_obj_t TRANSFORM_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_k
     return self;
 }
 
+mp_obj_t TRANSFORM_custom(mp_obj_t self_in, mp_obj_t custom_in) {
+    _TRANSFORM_obj_t *transform = MP_OBJ_TO_PTR2(self_in, _TRANSFORM_obj_t);
+
+    if(!mp_obj_is_type(custom_in, &mp_type_list)) mp_raise_ValueError("custom: transform must be a list!");
+    mp_obj_list_t *list = MP_OBJ_TO_PTR2(custom_in, mp_obj_list_t);
+
+    if(list->len != 9)  mp_raise_ValueError("custom: expected 9 items!");
+
+    pp_mat3_t t = pp_mat3_identity();
+
+    t.v00 = mp_obj_get_float(list->items[0]);
+    t.v10 = mp_obj_get_float(list->items[1]);
+    t.v20 = mp_obj_get_float(list->items[2]);
+    t.v01 = mp_obj_get_float(list->items[3]);
+    t.v11 = mp_obj_get_float(list->items[4]);
+    t.v21 = mp_obj_get_float(list->items[5]);
+    t.v02 = mp_obj_get_float(list->items[6]);
+    t.v12 = mp_obj_get_float(list->items[7]);
+    t.v22 = mp_obj_get_float(list->items[8]);
+
+    pp_mat3_mul(&transform->transform, &t);
+
+    return mp_const_none;
+}
+
 mp_obj_t TRANSFORM_rotate(mp_obj_t self_in, mp_obj_t angle_in, mp_obj_t origin_in) {
     _TRANSFORM_obj_t *transform = MP_OBJ_TO_PTR2(self_in, _TRANSFORM_obj_t);
 
diff --git a/micropython/modules/picovector/picovector.h b/micropython/modules/picovector/picovector.h
index 71ffa7d35..f02c44dbc 100644
--- a/micropython/modules/picovector/picovector.h
+++ b/micropython/modules/picovector/picovector.h
@@ -29,6 +29,7 @@ extern mp_obj_t TRANSFORM_make_new(const mp_obj_type_t *type, size_t n_args, siz
 extern mp_obj_t TRANSFORM_rotate(mp_obj_t self_in, mp_obj_t angle_in, mp_obj_t origin_in);
 extern mp_obj_t TRANSFORM_translate(mp_obj_t self_in, mp_obj_t x_in, mp_obj_t y_in);
 extern mp_obj_t TRANSFORM_scale(mp_obj_t self_in, mp_obj_t x_in, mp_obj_t y_in);
+extern mp_obj_t TRANSFORM_custom(mp_obj_t self_in, mp_obj_t custom_in);
 extern mp_obj_t TRANSFORM_reset(mp_obj_t self_in);
 
 /* Vector */