Use SkSL to do point-light shading
- misc fixes to utilities
- hit-testing for 3D scenes (simple version)
Had to manually inform the shader of the local-to-world matrix.
Should try making that automatic in the future.
Note: due to bug in interpreter, point-light sample can't run in raster
(yet).
Change-Id: I7a30b7676ea6cd7eb264373dd2507133c901d85e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/264999
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/include/core/SkCanvas.h b/include/core/SkCanvas.h
index fee4cae..79d74d9 100644
--- a/include/core/SkCanvas.h
+++ b/include/core/SkCanvas.h
@@ -881,6 +881,7 @@
void concat(const SkMatrix& matrix);
void experimental_concat44(const SkMatrix44&);
+ void experimental_concat44(const SkM44&);
void experimental_concat44(const SkScalar[]); // column-major
/** Replaces SkMatrix with matrix.
diff --git a/include/private/SkM44.h b/include/private/SkM44.h
index 2aa0110..58216c6 100644
--- a/include/private/SkM44.h
+++ b/include/private/SkM44.h
@@ -176,7 +176,7 @@
SkV4 map(float x, float y, float z, float w) const;
SkV4 operator*(const SkV4& v) const {
- return this->map(v.x, v.y, v.z, v.z);
+ return this->map(v.x, v.y, v.z, v.w);
}
SkV3 operator*(const SkV3& v) const {
auto v4 = this->map(v.x, v.y, v.z, 0);
diff --git a/samplecode/Sample.cpp b/samplecode/Sample.cpp
index c2ba788..3f92d82 100644
--- a/samplecode/Sample.cpp
+++ b/samplecode/Sample.cpp
@@ -66,7 +66,7 @@
case skui::InputState::kDown:
fClick = nullptr;
if (point.x() < 0 || point.y() < 0 || point.x() >= fWidth || point.y() >= fHeight) {
- return false;
+ // return false;
}
fClick.reset(this->onFindClickHandler(point.x(), point.y(), modifierKeys));
if (!fClick) {
diff --git a/samplecode/Sample3D.cpp b/samplecode/Sample3D.cpp
index 1410fb6..161a3a2 100644
--- a/samplecode/Sample3D.cpp
+++ b/samplecode/Sample3D.cpp
@@ -21,6 +21,17 @@
return inverse;
}
+static SkM44 inv(const SkM44& m) {
+ SkM44 inverse;
+ SkAssertResult(m.invert(&inverse));
+ return inverse;
+}
+
+static SkPoint project(const SkM44& m, SkV4 p) {
+ auto v = m * p;
+ return {v.x / v.w, v.y / v.w};
+}
+
class Sample3DView : public Sample {
protected:
float fNear = 0.05f;
@@ -57,6 +68,8 @@
viewport.setScale(area.width()*0.5f, area.height()*0.5f, zscale)
.postTranslate(area.centerX(), area.centerY(), 0);
+ // want "world" to be in our big coordinates (e.g. area), so apply this inverse
+ // as part of our "camera".
canvas->experimental_saveCamera(viewport * perspective, camera * inv(viewport));
}
@@ -103,6 +116,7 @@
struct Face {
SkScalar fRx, fRy;
+ SkColor fColor;
static SkMatrix44 T(SkScalar x, SkScalar y, SkScalar z) {
SkMatrix44 m;
@@ -134,14 +148,14 @@
}
const Face faces[] = {
- { 0, 0 }, // front
- { 0, SK_ScalarPI }, // back
+ { 0, 0, SK_ColorRED }, // front
+ { 0, SK_ScalarPI, SK_ColorGREEN }, // back
- { SK_ScalarPI/2, 0 }, // top
- {-SK_ScalarPI/2, 0 }, // bottom
+ { SK_ScalarPI/2, 0, SK_ColorBLUE }, // top
+ {-SK_ScalarPI/2, 0, SK_ColorCYAN }, // bottom
- { 0, SK_ScalarPI/2 }, // left
- { 0,-SK_ScalarPI/2 }, // right
+ { 0, SK_ScalarPI/2, SK_ColorMAGENTA }, // left
+ { 0,-SK_ScalarPI/2, SK_ColorYELLOW }, // right
};
#include "include/core/SkColorFilter.h"
@@ -272,3 +286,156 @@
}
};
DEF_SAMPLE( return new SampleRR3D(); )
+
+#include "include/effects/SkRuntimeEffect.h"
+
+struct LightPos {
+ SkV4 fPos;
+ SkScalar fUIRadius;
+
+ bool hitTest(SkScalar x, SkScalar y) const {
+ auto xx = x - fPos.x;
+ auto yy = y - fPos.y;
+ return xx*xx + yy*yy <= fUIRadius*fUIRadius;
+ }
+
+ void update(SkScalar x, SkScalar y) {
+ fPos.x = x;
+ fPos.y = y;
+ }
+
+ void draw(SkCanvas* canvas) {
+ SkPaint paint;
+ paint.setAntiAlias(true);
+
+ SkAutoCanvasRestore acr(canvas, true);
+ canvas->experimental_concat44(SkM44::Translate(0, 0, fPos.z));
+ canvas->drawCircle(fPos.x, fPos.y, fUIRadius, paint);
+ }
+};
+
+class SamplePointLight3D : public Sample3DView {
+ SkRRect fRR;
+ LightPos fLight = {{200, 200, 800, 1}, 8};
+
+ sk_sp<SkShader> fShader;
+ sk_sp<SkRuntimeEffect> fEffect;
+
+ SkM44 fWorldToClick,
+ fClickToWorld;
+
+ SkString name() override { return SkString("pointlight3d"); }
+
+ void onOnceBeforeDraw() override {
+ fRR = SkRRect::MakeRectXY({20, 20, 380, 380}, 50, 50);
+ fShader = GetResourceAsImage("images/mandrill_128.png")
+ ->makeShader(SkMatrix::MakeScale(3, 3));
+
+ const char code[] = R"(
+ // in fragmentProcessor texture;
+ // color = sample(texture) * half(scale);
+
+ uniform float4x4 localToWorld;
+ uniform float3 lightPos;
+
+ void main(float x, float y, inout half4 color) {
+ float3 plane_pos = (localToWorld * float4(x, y, 0, 1)).xyz;
+ float3 plane_norm = normalize((localToWorld * float4(0, 0, 1, 0)).xyz);
+ float3 light_dir = normalize(lightPos - plane_pos);
+ float ambient = 0.5;
+ float dp = dot(plane_norm, light_dir);
+ float scale = ambient + max(dp, 0);
+
+ color = color * half4(float4(scale, scale, scale, 1));
+ }
+ )";
+ auto [effect, error] = SkRuntimeEffect::Make(SkString(code));
+ if (!effect) {
+ SkDebugf("runtime error %s\n", error.c_str());
+ }
+ fEffect = effect;
+ }
+
+ bool onChar(SkUnichar uni) override {
+ switch (uni) {
+ case 'X': fLight.fPos.x += 10; return true;
+ case 'x': fLight.fPos.x -= 10; return true;
+ case 'Y': fLight.fPos.y += 10; return true;
+ case 'y': fLight.fPos.y -= 10; return true;
+ case 'Z': fLight.fPos.z += 10; return true;
+ case 'z': fLight.fPos.z -= 10; return true;
+ }
+ return this->Sample3DView::onChar(uni);
+ }
+
+ void drawContent(SkCanvas* canvas, const SkMatrix44& m, SkColor color) {
+ SkMatrix44 trans;
+ trans.setTranslate(200, 200, 0); // center of the rotation
+
+ canvas->experimental_concat44(trans * fRot * m * inv(trans));
+
+ // wonder if the runtimeeffect can do this reject? (in a setup function)
+ if (!front(canvas->experimental_getLocalToDevice())) {
+ return;
+ }
+
+ struct Uniforms {
+ SkM44 fLocalToWorld;
+ SkV3 fLightPos;
+ } uni;
+ uni.fLocalToWorld = canvas->experimental_getLocalToWorld();
+ uni.fLightPos = {fLight.fPos.x, fLight.fPos.y, fLight.fPos.z};
+ sk_sp<SkData> data = SkData::MakeWithCopy(&uni, sizeof(uni));
+
+ SkPaint paint;
+ paint.setColor(color);
+ paint.setShader(fEffect->makeShader(data, &fShader, 0, nullptr, true));
+
+ canvas->drawRRect(fRR, paint);
+ }
+
+ void setClickToWorld(SkCanvas* canvas, const SkM44& clickM) {
+ auto l2d = canvas->experimental_getLocalToDevice();
+ fWorldToClick = inv(clickM) * l2d;
+ fClickToWorld = inv(fWorldToClick);
+ }
+
+ void onDrawContent(SkCanvas* canvas) override {
+ if (canvas->getGrContext() == nullptr) {
+ return;
+ }
+ SkM44 clickM = canvas->experimental_getLocalToDevice();
+
+ canvas->save();
+ canvas->translate(400, 300);
+
+ this->saveCamera(canvas, {0, 0, 400, 400}, 200);
+
+ this->setClickToWorld(canvas, clickM);
+
+ for (auto f : faces) {
+ SkAutoCanvasRestore acr(canvas, true);
+ this->drawContent(canvas, f.asM44(200), f.fColor);
+ }
+
+ fLight.draw(canvas);
+ canvas->restore();
+ canvas->restore();
+ }
+
+ Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi) override {
+ auto L = fWorldToClick * fLight.fPos;
+ SkPoint c = project(fClickToWorld, {x, y, L.z/L.w, 1});
+ if (fLight.hitTest(c.fX, c.fY)) {
+ return new Click();
+ }
+ return nullptr;
+ }
+ bool onClick(Click* click) override {
+ auto L = fWorldToClick * fLight.fPos;
+ SkPoint c = project(fClickToWorld, {click->fCurr.fX, click->fCurr.fY, L.z/L.w, 1});
+ fLight.update(c.fX, c.fY);
+ return true;
+ }
+};
+DEF_SAMPLE( return new SamplePointLight3D(); )
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index f9d9621..e0310f8 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -1520,6 +1520,10 @@
this->experimental_concat44(m.values());
}
+void SkCanvas::experimental_concat44(const SkM44& m) {
+ this->experimental_concat44(m.asColMajor());
+}
+
void SkCanvas::internalSetMatrix(const SkMatrix& matrix) {
fMCRec->fMatrix = matrix;
fIsScaleTranslate = matrix.isScaleTranslate();
