mixercolorfilter.cpp File Reference

#include "gm/gm.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkColor.h"
#include "include/core/SkColorFilter.h"
#include "include/core/SkImage.h"
#include "include/core/SkMatrix.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkShader.h"
#include "include/core/SkSize.h"
#include "include/core/SkString.h"
#include "include/core/SkTileMode.h"
#include "include/core/SkTypes.h"
#include "include/effects/SkGradientShader.h"
#include "include/effects/SkLumaColorFilter.h"
#include "tools/Resources.h"
#include <math.h>

Go to the source code of this file.

Functions
static sk_sp< SkColorFilter >	MakeTintColorFilter (SkColor lo, SkColor hi)

Function Documentation

MakeTintColorFilter()

static sk_sp< SkColorFilter > MakeTintColorFilter ( SkColor  lo, SkColor  hi  )

static

Definition at line 36 of file mixercolorfilter.cpp.

                                                                        {
    const auto r_lo = SkColorGetR(lo),
    g_lo = SkColorGetG(lo),
    b_lo = SkColorGetB(lo),
    a_lo = SkColorGetA(lo),
    r_hi = SkColorGetR(hi),
    g_hi = SkColorGetG(hi),
    b_hi = SkColorGetB(hi),
    a_hi = SkColorGetA(hi);
 
    // We map component-wise:
    //
    //   r' = lo.r + (hi.r - lo.r) * luma
    //   g' = lo.g + (hi.g - lo.g) * luma
    //   b' = lo.b + (hi.b - lo.b) * luma
    //   a' = lo.a + (hi.a - lo.a) * luma
    //
    // The input luminance is stored in the alpha channel
    // (and RGB are cleared -- see SkLumaColorFilter). Thus:
    const float tint_matrix[] = {
        0, 0, 0, (r_hi - r_lo) / 255.0f, SkIntToScalar(r_lo) / 255.0f,
        0, 0, 0, (g_hi - g_lo) / 255.0f, SkIntToScalar(g_lo) / 255.0f,
        0, 0, 0, (b_hi - b_lo) / 255.0f, SkIntToScalar(b_lo) / 255.0f,
        0, 0, 0, (a_hi - a_lo) / 255.0f, SkIntToScalar(a_lo) / 255.0f,
    };
 
    return SkColorFilters::Matrix(tint_matrix)->makeComposed(SkLumaColorFilter::Make());
}