skia2/samplecode/Sample3D.cpp
Mike Reed 2d4a28ef9f use vsphere to control light
Change-Id: Iec36d5bff6d1d6cd07a55c44d46e49f922166312
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/266717
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>
2020-01-26 04:02:50 +00:00

700 lines
22 KiB
C++

/*
* Copyright 2020 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "include/core/SkCanvas.h"
#include "include/core/SkPaint.h"
#include "include/core/SkRRect.h"
#include "include/private/SkM44.h"
#include "include/utils/Sk3D.h"
#include "include/utils/SkRandom.h"
#include "samplecode/Sample.h"
#include "tools/Resources.h"
static SkV3 normalize(SkV3 v) { return v * (1.0f / v.length()); }
struct SkVec2 {
SkScalar x, y;
bool operator==(const SkVec2 v) const { return x == v.x && y == v.y; }
bool operator!=(const SkVec2 v) const { return !(*this == v); }
static SkScalar Dot(SkVec2 a, SkVec2 b) { return a.x * b.x + a.y * b.y; }
static SkScalar Cross(SkVec2 a, SkVec2 b) { return a.x * b.y - a.y * b.x; }
SkVec2 operator-() const { return {-x, -y}; }
SkVec2 operator+(SkVec2 v) const { return {x+v.x, y+v.y}; }
SkVec2 operator-(SkVec2 v) const { return {x-v.x, y-v.y}; }
SkVec2 operator*(SkVec2 v) const { return {x*v.x, y*v.y}; }
friend SkVec2 operator*(SkVec2 v, SkScalar s) { return {v.x*s, v.y*s}; }
friend SkVec2 operator*(SkScalar s, SkVec2 v) { return {v.x*s, v.y*s}; }
void operator+=(SkVec2 v) { *this = *this + v; }
void operator-=(SkVec2 v) { *this = *this - v; }
void operator*=(SkVec2 v) { *this = *this * v; }
void operator*=(SkScalar s) { *this = *this * s; }
SkScalar lengthSquared() const { return Dot(*this, *this); }
SkScalar length() const { return SkScalarSqrt(this->lengthSquared()); }
SkScalar dot(SkVec2 v) const { return Dot(*this, v); }
SkScalar cross(SkVec2 v) const { return Cross(*this, v); }
};
static SkVec2 normalize(SkVec2 v) {
SkScalar len = v.length();
SkASSERT(len > 0);
return v * (1.0f / len);
}
struct VSphere {
SkVec2 fCenter;
SkScalar fRadius;
VSphere(SkVec2 center, SkScalar radius) : fCenter(center), fRadius(radius) {}
bool contains(SkVec2 v) const {
return (v - fCenter).length() <= fRadius;
}
SkVec2 pinLoc(SkVec2 p) const {
auto v = p - fCenter;
if (v.length() > fRadius) {
v *= (fRadius / v.length());
}
return fCenter + v;
}
SkV3 computeUnitV3(SkVec2 v) const {
v = (v - fCenter) * (1 / fRadius);
SkScalar len2 = v.lengthSquared();
if (len2 > 1) {
v = normalize(v);
len2 = 1;
}
SkScalar z = SkScalarSqrt(1 - len2);
return {v.x, v.y, z};
}
SkM44 computeRotation(SkVec2 a, SkVec2 b) {
SkV3 u = this->computeUnitV3(a);
SkV3 v = this->computeUnitV3(b);
SkV3 axis = u.cross(v);
SkScalar sinValue = axis.length();
SkScalar cosValue = u.dot(v);
SkM44 m;
if (!SkScalarNearlyZero(sinValue)) {
m.setRotateUnitSinCos(axis * (1.0f / sinValue), sinValue, cosValue);
}
return m;
}
};
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;
float fFar = 4;
float fAngle = SK_ScalarPI / 12;
SkV3 fEye { 0, 0, 1.0f/tan(fAngle/2) - 1 };
SkV3 fCOA { 0, 0, 0 };
SkV3 fUp { 0, 1, 0 };
SkM44 fRot;
SkV3 fTrans;
void rotate(float x, float y, float z) {
SkM44 r;
if (x) {
r.setRotateUnit({1, 0, 0}, x);
} else if (y) {
r.setRotateUnit({0, 1, 0}, y);
} else {
r.setRotateUnit({0, 0, 1}, z);
}
fRot = r * fRot;
}
public:
void saveCamera(SkCanvas* canvas, const SkRect& area, SkScalar zscale) {
SkM44 camera = Sk3LookAt(fEye, fCOA, fUp),
perspective = Sk3Perspective(fNear, fFar, fAngle),
viewport = SkM44::Translate(area.centerX(), area.centerY(), 0) *
SkM44::Scale(area.width()*0.5f, area.height()*0.5f, zscale);
// 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));
}
bool onChar(SkUnichar uni) override {
float delta = SK_ScalarPI / 30;
switch (uni) {
case '8': this->rotate( delta, 0, 0); return true;
case '2': this->rotate(-delta, 0, 0); return true;
case '4': this->rotate(0, delta, 0); return true;
case '6': this->rotate(0, -delta, 0); return true;
case '-': this->rotate(0, 0, delta); return true;
case '+': this->rotate(0, 0, -delta); return true;
case 'i': fTrans.z += 0.1f; SkDebugf("z %g\n", fTrans.z); return true;
case 'k': fTrans.z -= 0.1f; SkDebugf("z %g\n", fTrans.z); return true;
case 'n': fNear += 0.1f; SkDebugf("near %g\n", fNear); return true;
case 'N': fNear -= 0.1f; SkDebugf("near %g\n", fNear); return true;
case 'f': fFar += 0.1f; SkDebugf("far %g\n", fFar); return true;
case 'F': fFar -= 0.1f; SkDebugf("far %g\n", fFar); return true;
default: break;
}
return false;
}
};
struct Face {
SkScalar fRx, fRy;
SkColor fColor;
static SkM44 T(SkScalar x, SkScalar y, SkScalar z) {
return SkM44::Translate(x, y, z);
}
static SkM44 R(SkV3 axis, SkScalar rad) {
return SkM44::Rotate(axis, rad);
}
SkM44 asM44(SkScalar scale) const {
return R({0,1,0}, fRy) * R({1,0,0}, fRx) * T(0, 0, scale);
}
};
static bool front(const SkM44& m) {
SkM44 m2;
m.invert(&m2);
/*
* Classically we want to dot the transpose(inverse(ctm)) with our surface normal.
* In this case, the normal is known to be {0, 0, 1}, so we only actually need to look
* at the z-scale of the inverse (the transpose doesn't change the main diagonal, so
* no need to actually transpose).
*/
return m2.rc(2,2) > 0;
}
const Face faces[] = {
{ 0, 0, SK_ColorRED }, // front
{ 0, SK_ScalarPI, SK_ColorGREEN }, // back
{ SK_ScalarPI/2, 0, SK_ColorBLUE }, // top
{-SK_ScalarPI/2, 0, SK_ColorCYAN }, // bottom
{ 0, SK_ScalarPI/2, SK_ColorMAGENTA }, // left
{ 0,-SK_ScalarPI/2, SK_ColorYELLOW }, // right
};
#include "include/core/SkColorFilter.h"
#include "include/effects/SkColorMatrix.h"
static SkColorMatrix comput_planar_lighting(SkCanvas* canvas, SkV3 lightDir) {
SkM44 l2w = canvas->experimental_getLocalToWorld();
auto normal = normalize(l2w * SkV3{0, 0, 1});
float dot = -normal.dot(lightDir);
SkColorMatrix cm;
if (dot < 0) {
dot = 0;
}
float ambient = 0.5f;
float scale = ambient + dot;
cm.setScale(scale, scale, scale, 1);
return cm;
}
struct Light {
SkPoint fCenter;
SkPoint fEndPt;
SkScalar fRadius;
SkScalar fHeight;
bool hitTest(SkScalar x, SkScalar y) const {
auto xx = x - fCenter.fX;
auto yy = y - fCenter.fY;
return xx*xx + yy*yy <= fRadius*fRadius;
}
void update(SkScalar x, SkScalar y) {
auto xx = x - fCenter.fX;
auto yy = y - fCenter.fY;
auto len = SkScalarSqrt(xx*xx + yy*yy);
if (len > fRadius) {
xx *= fRadius / len;
yy *= fRadius / len;
}
fEndPt = {fCenter.fX + xx, fCenter.fY + yy};
}
SkV3 getDir() const {
auto pt = fEndPt - fCenter;
return normalize({pt.fX, pt.fY, -fHeight});
}
void draw(SkCanvas* canvas) {
SkPaint paint;
paint.setAntiAlias(true);
canvas->drawCircle(fCenter.fX, fCenter.fY, 5, paint);
paint.setStyle(SkPaint::kStroke_Style);
canvas->drawCircle(fCenter.fX, fCenter.fY, fRadius, paint);
paint.setColor(SK_ColorRED);
canvas->drawLine(fCenter.fX, fCenter.fY, fEndPt.fX, fEndPt.fY, paint);
}
};
class SampleRR3D : public Sample3DView {
SkRRect fRR;
Light fLight = {
{60, 60}, {60, 60}, 50, 10
};
sk_sp<SkShader> fShader;
SkString name() override { return SkString("rrect3d"); }
void onOnceBeforeDraw() override {
fRR = SkRRect::MakeRectXY({20, 20, 380, 380}, 50, 50);
fShader = GetResourceAsImage("images/mandrill_128.png")
->makeShader(SkMatrix::MakeScale(3, 3));
}
bool onChar(SkUnichar uni) override {
return this->Sample3DView::onChar(uni);
}
void drawContent(SkCanvas* canvas, const SkM44& m) {
SkM44 trans = SkM44::Translate(200, 200, 0); // center of the rotation
canvas->experimental_concat44(trans * fRot * m * inv(trans));
if (!front(canvas->experimental_getLocalToDevice())) {
return;
}
SkPaint paint;
paint.setAlphaf(front(canvas->experimental_getLocalToDevice()) ? 1 : 0.25f);
paint.setShader(fShader);
SkColorMatrix cm = comput_planar_lighting(canvas, fLight.getDir());
paint.setColorFilter(SkColorFilters::Matrix(cm));
canvas->drawRRect(fRR, paint);
}
void onDrawContent(SkCanvas* canvas) override {
canvas->save();
canvas->translate(400, 300);
this->saveCamera(canvas, {0, 0, 400, 400}, 200);
for (auto f : faces) {
SkAutoCanvasRestore acr(canvas, true);
this->drawContent(canvas, f.asM44(200));
}
canvas->restore();
canvas->restore();
fLight.draw(canvas);
}
Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi) override {
if (fLight.hitTest(x, y)) {
return new Click();
}
return nullptr;
}
bool onClick(Click* click) override {
fLight.update(click->fCurr.fX, click->fCurr.fY);
return true;
}
};
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;
// TODO: Remove these helpers once all intrinsics work on the raster backend
float3 normalize_(float3 v) {
return v / sqrt(dot(v, v));
}
float max_(float a, float b) {
return a > b ? a : b;
}
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 '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 SkM44& m, SkColor color) {
SkM44 trans = SkM44::Translate(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 {
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(); )
#include "include/core/SkColorPriv.h"
#include "include/core/SkSurface.h"
struct LightOnSphere {
SkVec2 fLoc;
SkScalar fDistance;
SkScalar fRadius;
SkV3 computeWorldPos(const VSphere& s) const {
return s.computeUnitV3(fLoc) * fDistance;
}
void draw(SkCanvas* canvas) const {
SkPaint paint;
paint.setAntiAlias(true);
paint.setColor(SK_ColorWHITE);
canvas->drawCircle(fLoc.x, fLoc.y, fRadius + 2, paint);
paint.setColor(SK_ColorBLACK);
canvas->drawCircle(fLoc.x, fLoc.y, fRadius, paint);
}
};
class SampleBump3D : public Sample3DView {
enum {
DX = 400,
DY = 300
};
SkRRect fRR;
LightOnSphere fLight = {{200 + DX, 200 + DY}, 800, 12};
VSphere fSphere;
sk_sp<SkShader> fBmpShader, fImgShader;
sk_sp<SkRuntimeEffect> fEffect;
SkM44 fWorldToClick,
fClickToWorld;
SkM44 fRotation, // part of model
fClickRotation; // temp during a click/drag
public:
SampleBump3D() : fSphere({200 + DX, 200 + DY}, 400) {}
SkString name() override { return SkString("bump3d"); }
void onOnceBeforeDraw() override {
fRR = SkRRect::MakeRectXY({20, 20, 380, 380}, 50, 50);
auto img = GetResourceAsImage("images/brickwork-texture.jpg");
fImgShader = img->makeShader(SkMatrix::MakeScale(2, 2));
img = GetResourceAsImage("images/brickwork_normal-map.jpg");
fBmpShader = img->makeShader(SkMatrix::MakeScale(2, 2));
const char code[] = R"(
in fragmentProcessor color_map;
in fragmentProcessor normal_map;
uniform float4x4 localToWorld;
uniform float4x4 localToWorldAdjInv;
uniform float3 lightPos;
float3 convert_normal_sample(half4 c) {
float3 n = 2 * c.rgb - 1;
n.y = -n.y;
return n;
}
void main(float x, float y, inout half4 color) {
float3 norm = convert_normal_sample(sample(normal_map));
float3 plane_norm = normalize(localToWorld * float4(norm, 0)).xyz;
float3 plane_pos = (localToWorld * float4(x, y, 0, 1)).xyz;
float3 light_dir = normalize(lightPos - plane_pos);
float ambient = 0.2;
float dp = dot(plane_norm, light_dir);
float scale = min(ambient + max(dp, 0), 1);
color = sample(color_map) * 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 'Z': fLight.fDistance += 10; return true;
case 'z': fLight.fDistance -= 10; return true;
}
return this->Sample3DView::onChar(uni);
}
void drawContent(SkCanvas* canvas, const SkM44& m, SkColor color) {
SkM44 trans = SkM44::Translate(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;
}
auto adj_inv = [](const SkM44& m) {
SkM44 inv;
SkAssertResult(m.invert(&inv));
return inv.transpose();
};
struct Uniforms {
SkM44 fLocalToWorld;
SkM44 fLocalToWorldAdjInv;
SkV3 fLightPos;
} uni;
uni.fLocalToWorld = canvas->experimental_getLocalToWorld();
uni.fLocalToWorldAdjInv = adj_inv(uni.fLocalToWorld);
uni.fLightPos = fLight.computeWorldPos(fSphere);
sk_sp<SkData> data = SkData::MakeWithCopy(&uni, sizeof(uni));
sk_sp<SkShader> children[] = { fImgShader, fBmpShader };
SkPaint paint;
paint.setColor(color);
paint.setShader(fEffect->makeShader(data, children, 2, 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(DX, DY);
this->saveCamera(canvas, {0, 0, 400, 400}, 200);
this->setClickToWorld(canvas, clickM);
for (auto f : faces) {
SkAutoCanvasRestore acr(canvas, true);
this->drawContent(canvas, fClickRotation * fRotation * f.asM44(200), f.fColor);
}
canvas->restore(); // camera
canvas->restore(); // center the content in the window
fLight.draw(canvas);
{
SkPaint paint;
paint.setAntiAlias(true);
paint.setStyle(SkPaint::kStroke_Style);
paint.setColor(0x40FF0000);
canvas->drawCircle(fSphere.fCenter.x, fSphere.fCenter.y, fSphere.fRadius, paint);
canvas->drawLine(fSphere.fCenter.x, fSphere.fCenter.y - fSphere.fRadius,
fSphere.fCenter.x, fSphere.fCenter.y + fSphere.fRadius, paint);
canvas->drawLine(fSphere.fCenter.x - fSphere.fRadius, fSphere.fCenter.y,
fSphere.fCenter.x + fSphere.fRadius, fSphere.fCenter.y, paint);
}
}
Click* onFindClickHandler(SkScalar x, SkScalar y, skui::ModifierKey modi) override {
SkVec2 p = fLight.fLoc - SkVec2{x, y};
if (p.length() <= fLight.fRadius) {
Click* c = new Click();
c->fMeta.setS32("type", 0);
return c;
}
if (fSphere.contains({x, y})) {
Click* c = new Click();
c->fMeta.setS32("type", 1);
return c;
}
return nullptr;
}
bool onClick(Click* click) override {
#if 0
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);
#endif
if (click->fMeta.hasS32("type", 0)) {
fLight.fLoc = fSphere.pinLoc({click->fCurr.fX, click->fCurr.fY});
return true;
}
if (click->fMeta.hasS32("type", 1)) {
if (click->fState == skui::InputState::kUp) {
fRotation = fClickRotation * fRotation;
fClickRotation.setIdentity();
} else {
fClickRotation = fSphere.computeRotation({click->fOrig.fX, click->fOrig.fY},
{click->fCurr.fX, click->fCurr.fY});
}
return true;
}
return true;
}
};
DEF_SAMPLE( return new SampleBump3D; )