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/*
* Copyright 2015 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkLights_DEFINED
#define SkLights_DEFINED
#include "SkPoint3.h"
#include "SkRefCnt.h"
#include "../private/SkTArray.h"
class SkReadBuffer;
class SkWriteBuffer;
/** \class SkLights
SkLights encapsulates a set of directional, point and ambient lights for use with the
SkLightingShader.
*/
class SK_API SkLights : public SkRefCnt {
public:
class Light {
public:
enum LightType {
kDirectional_LightType,
kPoint_LightType
};
Light(const Light& other)
: fType(other.fType)
, fColor(other.fColor)
, fDirOrPos(other.fDirOrPos)
, fIntensity(other.fIntensity) {}
Light(Light&& other)
: fType(other.fType)
, fColor(other.fColor)
, fDirOrPos(other.fDirOrPos)
, fIntensity(other.fIntensity) {}
static Light MakeDirectional(const SkColor3f& color, const SkVector3& dir) {
Light light(kDirectional_LightType, color, dir, 0.0f);
if (!light.fDirOrPos.normalize()) {
light.fDirOrPos.set(0.0f, 0.0f, 1.0f);
}
return light;
}
static Light MakePoint(const SkColor3f& color, const SkPoint3& pos, SkScalar intensity) {
return Light(kPoint_LightType, color, pos, intensity);
}
LightType type() const { return fType; }
const SkColor3f& color() const { return fColor; }
const SkVector3& dir() const {
SkASSERT(kDirectional_LightType == fType);
return fDirOrPos;
}
const SkPoint3& pos() const {
SkASSERT(kPoint_LightType == fType);
return fDirOrPos;
}
SkScalar intensity() const {
SkASSERT(kPoint_LightType == fType);
return fIntensity;
}
Light& operator=(const Light& other) {
if (this == &other) {
return *this;
}
fType = other.fType;
fColor = other.fColor;
fDirOrPos = other.fDirOrPos;
fIntensity = other.fIntensity;
return *this;
}
bool operator==(const Light& other) {
return (fType == other.fType) &&
(fColor == other.fColor) &&
(fDirOrPos == other.fDirOrPos) &&
(fIntensity == other.fIntensity);
}
bool operator!=(const Light& other) { return !(this->operator==(other)); }
private:
friend class SkLights;
Light(LightType type, const SkColor3f& color, const SkVector3& dirOrPos,
SkScalar intensity)
: fType(type)
, fColor(color)
, fDirOrPos(dirOrPos)
, fIntensity(intensity) {}
LightType fType;
SkColor3f fColor; // linear (unpremul) color. Range is 0..1 in each channel.
SkVector3 fDirOrPos; // For directional lights, holds the direction towards the
// light (+Z is out of the screen).
// If degenerate, it will be replaced with (0, 0, 1).
// For point lights, holds location of point light
SkScalar fIntensity; // For point lights, dictates the light intensity.
// Simply a multiplier to the final light output value.
};
class Builder {
public:
Builder() : fLights(new SkLights) {}
void add(const Light& light) {
if (fLights) {
fLights->fLights.push_back(light);
}
}
void add(Light&& light) {
if (fLights) {
fLights->fLights.push_back(std::move(light));
}
}
void setAmbientLightColor(const SkColor3f& color) {
if (fLights) {
fLights->fAmbientLightColor = color;
}
}
sk_sp<SkLights> finish() {
return std::move(fLights);
}
private:
sk_sp<SkLights> fLights;
};
/** Returns number of lights not including the ambient light.
@return number of lights not including the ambient light
*/
int numLights() const { return fLights.count(); }
/** Returns the index-th light.
@param index the index of the desired light
@return the index-th light
*/
const Light& light(int index) const { return fLights[index]; }
/** Returns the ambient light.
@return the ambient light
*/
const SkColor3f& ambientLightColor() const {
return fAmbientLightColor;
}
/**
* Recreate an SkLights object that was serialized into a buffer.
*
* @param SkReadBuffer Serialized blob data.
* @return A new SkLights representing the serialized data, or NULL if the buffer is
* invalid.
*/
static sk_sp<SkLights> MakeFromBuffer(SkReadBuffer& buf);
/**
* Serialize to a buffer.
*
* @param buffer the write buffer to write out to
*/
void flatten(SkWriteBuffer& buf) const;
private:
friend class SkLightingShaderImpl;
SkLights() : fAmbientLightColor(SkColor3f::Make(0.0f, 0.0f, 0.0f)) {}
SkTArray<Light> fLights;
SkColor3f fAmbientLightColor;
typedef SkRefCnt INHERITED;
};
#endif