threshold rtshader
Change-Id: Ia1a0e35f2cb7cf2f7fd1a58b88dc81ec59eced0b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/268943
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Reed <reed@google.com>
diff --git a/gm/runtimeshader.cpp b/gm/runtimeshader.cpp
index b84d310..930193b 100644
--- a/gm/runtimeshader.cpp
+++ b/gm/runtimeshader.cpp
@@ -11,7 +11,9 @@
#include "include/core/SkPaint.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
+#include "include/effects/SkImageFilters.h"
#include "include/effects/SkRuntimeEffect.h"
+#include "tools/Resources.h"
const char* gProg = R"(
uniform half4 gColor;
@@ -44,3 +46,132 @@
}
};
DEF_GM(return new RuntimeShader;)
+
+static sk_sp<SkShader> make_shader(sk_sp<SkImage> img, SkISize size) {
+ SkMatrix scale = SkMatrix::MakeScale(size.width() / (float)img->width(),
+ size.height() / (float)img->height());
+ return img->makeShader(SkTileMode::kClamp, SkTileMode::kClamp, &scale);
+}
+
+#include "include/core/SkSurface.h"
+#include "include/effects/SkGradientShader.h"
+#include "include/utils/SkRandom.h"
+
+static sk_sp<SkShader> make_threshold(SkISize size) {
+ auto info = SkImageInfo::Make(size.width(), size.height(), kAlpha_8_SkColorType,
+ kPremul_SkAlphaType);
+ auto surf = SkSurface::MakeRaster(info);
+ auto canvas = surf->getCanvas();
+
+ const SkScalar rad = 50;
+ SkColor colors[] = {SK_ColorBLACK, 0};
+ SkPaint paint;
+ paint.setAntiAlias(true);
+ paint.setShader(SkGradientShader::MakeRadial({0,0}, rad, colors, nullptr, 2, SkTileMode::kClamp));
+
+ SkPaint layerPaint;
+ const SkScalar sigma = 16.0f;
+ layerPaint.setImageFilter(SkImageFilters::Blur(sigma, sigma, nullptr));
+ canvas->saveLayer(nullptr, &layerPaint);
+
+ SkRandom rand;
+ for (int i = 0; i < 25; ++i) {
+ SkScalar x = rand.nextF() * size.width();
+ SkScalar y = rand.nextF() * size.height();
+ canvas->save();
+ canvas->translate(x, y);
+ canvas->drawCircle(0, 0, rad, paint);
+ canvas->restore();
+ }
+
+ canvas->restore(); // apply the blur
+
+ return surf->makeImageSnapshot()->makeShader();
+}
+
+class ThresholdRT : public skiagm::GM {
+ sk_sp<SkShader> fBefore, fAfter, fThreshold;
+ sk_sp<SkRuntimeEffect> fEffect;
+
+ float fCutoff = 0.5; // so we get something interested when we're not animated
+
+ void onOnceBeforeDraw() override {
+ const SkISize size = {256, 256};
+ fThreshold = make_threshold(size);
+ fBefore = make_shader(GetResourceAsImage("images/mandrill_256.png"), size);
+ fAfter = make_shader(GetResourceAsImage("images/dog.jpg"), size);
+
+ const char code[] = R"(
+ in fragmentProcessor before_map;
+ in fragmentProcessor after_map;
+ in fragmentProcessor threshold_map;
+
+ uniform float cutoff;
+ uniform float slope;
+
+ float smooth_cutoff(float x) {
+ x = x * slope + (0.5 - slope * cutoff);
+ return clamp(x, 0, 1);
+ }
+
+ void main(float2 xy, inout half4 color) {
+ half4 before = sample(before_map, xy);
+ half4 after = sample(after_map, xy);
+
+ float m = smooth_cutoff(sample(threshold_map, xy).r);
+ color = mix(before, after, half(m));
+ }
+ )";
+ auto [effect, error] = SkRuntimeEffect::Make(SkString(code));
+ if (!effect) {
+ SkDebugf("runtime error %s\n", error.c_str());
+ }
+ fEffect = effect;
+ }
+
+ bool runAsBench() const override { return true; }
+
+ SkString onShortName() override { return SkString("threshold_rt"); }
+
+ SkISize onISize() override { return {256, 256}; }
+
+ DrawResult onDraw(SkCanvas* canvas, SkString* errorMsg) override {
+ if (canvas->getGrContext() == nullptr) {
+ // until SkSL can handle child processors on the raster backend
+ return DrawResult::kSkip;
+ }
+
+ struct {
+ float cutoff, slope;
+ } uni = {
+ fCutoff, 10
+ };
+ sk_sp<SkData> data = SkData::MakeWithCopy(&uni, sizeof(uni));
+ sk_sp<SkShader> children[] = { fBefore, fAfter, fThreshold };
+
+ SkPaint paint;
+ paint.setShader(fEffect->makeShader(data, children, SK_ARRAY_COUNT(children),
+ nullptr, true));
+ canvas->drawRect({0, 0, 256, 256}, paint);
+
+ auto draw = [&](SkScalar x, SkScalar y, sk_sp<SkShader> shader) {
+ paint.setShader(shader);
+ canvas->save();
+ canvas->translate(x, y);
+ canvas->drawRect({0, 0, 256, 256}, paint);
+ canvas->restore();
+ };
+ draw(256, 0, fThreshold);
+ draw( 0, 256, fBefore);
+ draw(256, 256, fAfter);
+
+ return DrawResult::kOk;
+ }
+
+ bool onAnimate(double nanos) override {
+ double t = sin(nanos / (1000 * 1000 * 1000));
+ fCutoff = float(t + 1) * 0.55f - 0.05f;
+ return true;
+ }
+};
+DEF_GM(return new ThresholdRT;)
