gfx/skia/trunk/src/gpu/FlingState.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Sat, 03 Jan 2015 20:18:00 +0100
branch
TOR_BUG_3246
changeset 7
129ffea94266
permissions
-rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

michael@0 1
michael@0 2 /*
michael@0 3 * Copyright 2010 Google Inc.
michael@0 4 *
michael@0 5 * Use of this source code is governed by a BSD-style license that can be
michael@0 6 * found in the LICENSE file.
michael@0 7 */
michael@0 8
michael@0 9
michael@0 10
michael@0 11 #include "FlingState.h"
michael@0 12 #include "SkMatrix.h"
michael@0 13 #include "SkTime.h"
michael@0 14
michael@0 15 #define DISCRETIZE_TRANSLATE_TO_AVOID_FLICKER true
michael@0 16
michael@0 17 static const float MAX_FLING_SPEED = 1500;
michael@0 18
michael@0 19 static float pin_max_fling(float speed) {
michael@0 20 if (speed > MAX_FLING_SPEED) {
michael@0 21 speed = MAX_FLING_SPEED;
michael@0 22 }
michael@0 23 return speed;
michael@0 24 }
michael@0 25
michael@0 26 static double getseconds() {
michael@0 27 return SkTime::GetMSecs() * 0.001;
michael@0 28 }
michael@0 29
michael@0 30 // returns +1 or -1, depending on the sign of x
michael@0 31 // returns +1 if x is zero
michael@0 32 static SkScalar SkScalarSign(SkScalar x) {
michael@0 33 SkScalar sign = SK_Scalar1;
michael@0 34 if (x < 0) {
michael@0 35 sign = -sign;
michael@0 36 }
michael@0 37 return sign;
michael@0 38 }
michael@0 39
michael@0 40 static void unit_axis_align(SkVector* unit) {
michael@0 41 const SkScalar TOLERANCE = SkDoubleToScalar(0.15);
michael@0 42 if (SkScalarAbs(unit->fX) < TOLERANCE) {
michael@0 43 unit->fX = 0;
michael@0 44 unit->fY = SkScalarSign(unit->fY);
michael@0 45 } else if (SkScalarAbs(unit->fY) < TOLERANCE) {
michael@0 46 unit->fX = SkScalarSign(unit->fX);
michael@0 47 unit->fY = 0;
michael@0 48 }
michael@0 49 }
michael@0 50
michael@0 51 void FlingState::reset(float sx, float sy) {
michael@0 52 fActive = true;
michael@0 53 fDirection.set(sx, sy);
michael@0 54 fSpeed0 = SkPoint::Normalize(&fDirection);
michael@0 55 fSpeed0 = pin_max_fling(fSpeed0);
michael@0 56 fTime0 = getseconds();
michael@0 57
michael@0 58 unit_axis_align(&fDirection);
michael@0 59 // printf("---- speed %g dir %g %g\n", fSpeed0, fDirection.fX, fDirection.fY);
michael@0 60 }
michael@0 61
michael@0 62 bool FlingState::evaluateMatrix(SkMatrix* matrix) {
michael@0 63 if (!fActive) {
michael@0 64 return false;
michael@0 65 }
michael@0 66
michael@0 67 const float t = getseconds() - fTime0;
michael@0 68 const float MIN_SPEED = 2;
michael@0 69 const float K0 = 5.0;
michael@0 70 const float K1 = 0.02;
michael@0 71 const float speed = fSpeed0 * (sk_float_exp(- K0 * t) - K1);
michael@0 72 if (speed <= MIN_SPEED) {
michael@0 73 fActive = false;
michael@0 74 return false;
michael@0 75 }
michael@0 76 float dist = (fSpeed0 - speed) / K0;
michael@0 77
michael@0 78 // printf("---- time %g speed %g dist %g\n", t, speed, dist);
michael@0 79 float tx = fDirection.fX * dist;
michael@0 80 float ty = fDirection.fY * dist;
michael@0 81 if (DISCRETIZE_TRANSLATE_TO_AVOID_FLICKER) {
michael@0 82 tx = sk_float_round2int(tx);
michael@0 83 ty = sk_float_round2int(ty);
michael@0 84 }
michael@0 85 matrix->setTranslate(tx, ty);
michael@0 86 // printf("---- evaluate (%g %g)\n", tx, ty);
michael@0 87
michael@0 88 return true;
michael@0 89 }
michael@0 90
michael@0 91 ////////////////////////////////////////
michael@0 92
michael@0 93 GrAnimateFloat::GrAnimateFloat() : fTime0(0) {}
michael@0 94
michael@0 95 void GrAnimateFloat::start(float v0, float v1, float duration) {
michael@0 96 fValue0 = v0;
michael@0 97 fValue1 = v1;
michael@0 98 fDuration = duration;
michael@0 99 if (duration > 0) {
michael@0 100 fTime0 = SkTime::GetMSecs();
michael@0 101 if (!fTime0) {
michael@0 102 fTime0 = 1; // time0 is our sentinel
michael@0 103 }
michael@0 104 } else {
michael@0 105 fTime0 = 0;
michael@0 106 }
michael@0 107 }
michael@0 108
michael@0 109 float GrAnimateFloat::evaluate() {
michael@0 110 if (!fTime0) {
michael@0 111 return fValue1;
michael@0 112 }
michael@0 113
michael@0 114 double elapsed = (SkTime::GetMSecs() - fTime0) * 0.001;
michael@0 115 if (elapsed >= fDuration) {
michael@0 116 fTime0 = 0;
michael@0 117 return fValue1;
michael@0 118 }
michael@0 119
michael@0 120 double t = elapsed / fDuration;
michael@0 121 if (true) {
michael@0 122 t = (3 - 2 * t) * t * t;
michael@0 123 }
michael@0 124 return fValue0 + t * (fValue1 - fValue0);
michael@0 125 }

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