xref: /aosp_15_r20/external/skia/docs/examples/Canvas_drawTextRSXform.cpp (revision c8dee2aa9b3f27cf6c858bd81872bdeb2c07ed17)
1*c8dee2aaSAndroid Build Coastguard Worker // Copyright 2019 Google LLC.
2*c8dee2aaSAndroid Build Coastguard Worker // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3*c8dee2aaSAndroid Build Coastguard Worker #include "tools/fiddle/examples.h"
4*c8dee2aaSAndroid Build Coastguard Worker REG_FIDDLE(Canvas_drawTextRSXform, 256, 256, false, 0) {
draw(SkCanvas * canvas)5*c8dee2aaSAndroid Build Coastguard Worker void draw(SkCanvas* canvas) {
6*c8dee2aaSAndroid Build Coastguard Worker     const int iterations = 26;
7*c8dee2aaSAndroid Build Coastguard Worker     SkRSXform transforms[iterations];
8*c8dee2aaSAndroid Build Coastguard Worker     char alphabet[iterations];
9*c8dee2aaSAndroid Build Coastguard Worker     SkScalar angle = 0;
10*c8dee2aaSAndroid Build Coastguard Worker     SkScalar scale = 1;
11*c8dee2aaSAndroid Build Coastguard Worker     for (size_t i = 0; i < std::size(transforms); ++i) {
12*c8dee2aaSAndroid Build Coastguard Worker         const SkScalar s = SkScalarSin(angle) * scale;
13*c8dee2aaSAndroid Build Coastguard Worker         const SkScalar c = SkScalarCos(angle) * scale;
14*c8dee2aaSAndroid Build Coastguard Worker         transforms[i] = SkRSXform::Make(-c, -s, -s * 16, c * 16);
15*c8dee2aaSAndroid Build Coastguard Worker         angle += .45f;
16*c8dee2aaSAndroid Build Coastguard Worker         scale += .2f;
17*c8dee2aaSAndroid Build Coastguard Worker         alphabet[i] = 'A' + i;
18*c8dee2aaSAndroid Build Coastguard Worker     }
19*c8dee2aaSAndroid Build Coastguard Worker     SkPaint paint;
20*c8dee2aaSAndroid Build Coastguard Worker     SkFont font(fontMgr->matchFamilyStyle(nullptr, {}), 20);
21*c8dee2aaSAndroid Build Coastguard Worker     auto spiral = SkTextBlob::MakeFromRSXform(alphabet, sizeof(alphabet), transforms, font);
22*c8dee2aaSAndroid Build Coastguard Worker     canvas->drawTextBlob(spiral, 110, 138, paint);
23*c8dee2aaSAndroid Build Coastguard Worker }
24*c8dee2aaSAndroid Build Coastguard Worker }  // END FIDDLE
25