1 // Copyright 2024 Google LLC.
2 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3 #include "tools/fiddle/examples.h"
4 REG_FIDDLE(SkSL_CoordinateSpaces, 128, 128, false, 5) {
draw(SkCanvas * canvas)5 void draw(SkCanvas* canvas) {
6 const char* sksl =
7 "uniform shader image;"
8 "half4 main(float2 coord) {"
9 " coord.x += sin(coord.y / 3) * 4;" // Displace each row by up to 4 pixels
10 " return image.eval(coord);"
11 "}";
12
13 // Draw the SkSL shader, with an image shader bound to `image`: // SK_FOLD_START
14
15 // Turn `image` into an SkShader:
16 sk_sp<SkShader> imageShader = image->makeShader(SkSamplingOptions(SkFilterMode::kLinear));
17
18 // Parse the SkSL, and create an SkRuntimeEffect object:
19 auto [effect, err] = SkRuntimeEffect::MakeForShader(SkString(sksl));
20
21 // SkRuntimeEffect::makeShader expects an SkSpan<ChildPtr>, one per `uniform shader`:
22 SkRuntimeEffect::ChildPtr children[] = { imageShader };
23
24 // Create an SkShader from our SkSL, with `imageShader` bound to `image`:
25 sk_sp<SkShader> myShader = effect->makeShader(/*uniforms=*/ nullptr,
26 /*children=*/ { children, 1 });
27
28 // Fill the surface with `myShader`:
29 SkPaint p;
30 p.setShader(myShader);
31 canvas->drawPaint(p);
32 // SK_FOLD_END
33 }
34 } // END FIDDLE
35