include/effects/SkLightingImageFilter.h

/*
 * Copyright 2012 The Android Open Source Project
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkLightingImageFilter_DEFINED
#define SkLightingImageFilter_DEFINED

#include "SkImageFilter.h"
#include "SkColor.h"

class SK_API SkPoint3 {
public:
    SkPoint3() {}
    SkPoint3(SkScalar x, SkScalar y, SkScalar z)
      : fX(x), fY(y), fZ(z) {}
    SkScalar dot(const SkPoint3& other) const {
        return fX * other.fX + fY * other.fY + fZ * other.fZ;
    }
    SkScalar maxComponent() const {
        return fX > fY ? (fX > fZ ? fX : fZ) : (fY > fZ ? fY : fZ);
    }
    void normalize() {
        // Small epsilon is added to prevent division by 0.
        SkScalar scale = SkScalarInvert(SkScalarSqrt(dot(*this)) + SK_ScalarNearlyZero);
        fX = fX * scale;
        fY = fY * scale;
        fZ = fZ * scale;
    }
    SkPoint3 operator*(SkScalar scalar) const {
        return SkPoint3(fX * scalar, fY * scalar, fZ * scalar);
    }
    SkPoint3 operator-(const SkPoint3& other) const {
        return SkPoint3(fX - other.fX, fY - other.fY, fZ - other.fZ);
    }
    bool operator==(const SkPoint3& other) const {
        return fX == other.fX && fY == other.fY && fZ == other.fZ;
    }
    SkScalar fX, fY, fZ;
};

class SkLight;

class SK_API SkLightingImageFilter : public SkImageFilter {
public:
    static SkImageFilter* CreateDistantLitDiffuse(const SkPoint3& direction,
        SkColor lightColor, SkScalar surfaceScale, SkScalar kd,
        SkImageFilter* input = NULL, const CropRect* cropRect = NULL);
    static SkImageFilter* CreatePointLitDiffuse(const SkPoint3& location,
        SkColor lightColor, SkScalar surfaceScale, SkScalar kd,
        SkImageFilter* input = NULL, const CropRect* cropRect = NULL);
    static SkImageFilter* CreateSpotLitDiffuse(const SkPoint3& location,
        const SkPoint3& target, SkScalar specularExponent, SkScalar cutoffAngle,
        SkColor lightColor, SkScalar surfaceScale, SkScalar kd,
        SkImageFilter* input = NULL, const CropRect* cropRect = NULL);
    static SkImageFilter* CreateDistantLitSpecular(const SkPoint3& direction,
        SkColor lightColor, SkScalar surfaceScale, SkScalar ks,
        SkScalar shininess, SkImageFilter* input = NULL, const CropRect* cropRect = NULL);
    static SkImageFilter* CreatePointLitSpecular(const SkPoint3& location,
        SkColor lightColor, SkScalar surfaceScale, SkScalar ks,
        SkScalar shininess, SkImageFilter* input = NULL, const CropRect* cropRect = NULL);
    static SkImageFilter* CreateSpotLitSpecular(const SkPoint3& location,
        const SkPoint3& target, SkScalar specularExponent, SkScalar cutoffAngle,
        SkColor lightColor, SkScalar surfaceScale, SkScalar ks,
        SkScalar shininess, SkImageFilter* input = NULL, const CropRect* cropRect = NULL);
    ~SkLightingImageFilter();

    SK_DECLARE_FLATTENABLE_REGISTRAR_GROUP()

protected:
    SkLightingImageFilter(SkLight* light,
                          SkScalar surfaceScale,
                          SkImageFilter* input,
                          const CropRect* cropRect,
                          uint32_t uniqueID);
#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
    explicit SkLightingImageFilter(SkReadBuffer& buffer);
#endif
    virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE;
    const SkLight* light() const { return fLight.get(); }
    SkScalar surfaceScale() const { return fSurfaceScale; }

private:
    typedef SkImageFilter INHERITED;
    SkAutoTUnref<SkLight> fLight;
    SkScalar fSurfaceScale;
};

#endif