blob: 32e3ad196362a546c597f3908edf945d2db92263 [file] [log] [blame]
// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CC_BASE_MATH_UTIL_H_
#define CC_BASE_MATH_UTIL_H_
#include <algorithm>
#include <cmath>
#include <memory>
#include <vector>
#include "base/logging.h"
#include "cc/base/base_export.h"
#include "ui/gfx/geometry/box_f.h"
#include "ui/gfx/geometry/point3_f.h"
#include "ui/gfx/geometry/point_f.h"
#include "ui/gfx/geometry/scroll_offset.h"
#include "ui/gfx/geometry/size.h"
#include "ui/gfx/transform.h"
namespace base {
class Value;
namespace trace_event {
class TracedValue;
}
} // namespace base
namespace gfx {
class QuadF;
class Rect;
class RectF;
class SizeF;
class Transform;
class Vector2dF;
class Vector2d;
class Vector3dF;
}
namespace cc {
struct HomogeneousCoordinate {
HomogeneousCoordinate(SkMScalar x, SkMScalar y, SkMScalar z, SkMScalar w) {
vec[0] = x;
vec[1] = y;
vec[2] = z;
vec[3] = w;
}
bool ShouldBeClipped() const { return w() <= 0.0; }
gfx::PointF CartesianPoint2d() const {
if (w() == SK_MScalar1)
return gfx::PointF(x(), y());
// For now, because this code is used privately only by MathUtil, it should
// never be called when w == 0, and we do not yet need to handle that case.
DCHECK(w());
SkMScalar inv_w = SK_MScalar1 / w();
return gfx::PointF(x() * inv_w, y() * inv_w);
}
gfx::Point3F CartesianPoint3d() const {
if (w() == SK_MScalar1)
return gfx::Point3F(x(), y(), z());
// For now, because this code is used privately only by MathUtil, it should
// never be called when w == 0, and we do not yet need to handle that case.
DCHECK(w());
SkMScalar inv_w = SK_MScalar1 / w();
return gfx::Point3F(x() * inv_w, y() * inv_w, z() * inv_w);
}
SkMScalar x() const { return vec[0]; }
SkMScalar y() const { return vec[1]; }
SkMScalar z() const { return vec[2]; }
SkMScalar w() const { return vec[3]; }
SkMScalar vec[4];
};
class CC_BASE_EXPORT MathUtil {
public:
static const double kPiDouble;
static const float kPiFloat;
static double Deg2Rad(double deg) { return deg * kPiDouble / 180.0; }
static double Rad2Deg(double rad) { return rad * 180.0 / kPiDouble; }
static float Deg2Rad(float deg) { return deg * kPiFloat / 180.0f; }
static float Rad2Deg(float rad) { return rad * 180.0f / kPiFloat; }
static float Round(float f) {
return (f > 0.f) ? std::floor(f + 0.5f) : std::ceil(f - 0.5f);
}
static double Round(double d) {
return (d > 0.0) ? std::floor(d + 0.5) : std::ceil(d - 0.5);
}
// Returns true if rounded up value does not overflow, false otherwise.
template <typename T>
static bool VerifyRoundup(T n, T mul) {
return mul && (n <= (std::numeric_limits<T>::max() -
(std::numeric_limits<T>::max() % mul)));
}
// Rounds up a given |n| to be a multiple of |mul|, but may overflow.
// Examples:
// - RoundUp(123, 50) returns 150.
// - RoundUp(-123, 50) returns -100.
template <typename T>
static T UncheckedRoundUp(T n, T mul) {
static_assert(std::numeric_limits<T>::is_integer,
"T must be an integer type");
DCHECK(VerifyRoundup(n, mul));
return RoundUpInternal(n, mul);
}
// Similar to UncheckedRoundUp(), but dies with a CRASH() if rounding up a
// given |n| overflows T.
template <typename T>
static T CheckedRoundUp(T n, T mul) {
static_assert(std::numeric_limits<T>::is_integer,
"T must be an integer type");
CHECK(VerifyRoundup(n, mul));
return RoundUpInternal(n, mul);
}
// Returns true if rounded down value does not underflow, false otherwise.
template <typename T>
static bool VerifyRoundDown(T n, T mul) {
return mul && (n >= (std::numeric_limits<T>::min() -
(std::numeric_limits<T>::min() % mul)));
}
// Rounds down a given |n| to be a multiple of |mul|, but may underflow.
// Examples:
// - RoundDown(123, 50) returns 100.
// - RoundDown(-123, 50) returns -150.
template <typename T>
static T UncheckedRoundDown(T n, T mul) {
static_assert(std::numeric_limits<T>::is_integer,
"T must be an integer type");
DCHECK(VerifyRoundDown(n, mul));
return RoundDownInternal(n, mul);
}
// Similar to UncheckedRoundDown(), but dies with a CRASH() if rounding down a
// given |n| underflows T.
template <typename T>
static T CheckedRoundDown(T n, T mul) {
static_assert(std::numeric_limits<T>::is_integer,
"T must be an integer type");
CHECK(VerifyRoundDown(n, mul));
return RoundDownInternal(n, mul);
}
template <typename T> static T ClampToRange(T value, T min, T max) {
return std::min(std::max(value, min), max);
}
// Background: Existing transform code does not do the right thing in
// MapRect / MapQuad / ProjectQuad when there is a perspective projection that
// causes one of the transformed vertices to go to w < 0. In those cases, it
// is necessary to perform clipping in homogeneous coordinates, after applying
// the transform, before dividing-by-w to convert to cartesian coordinates.
//
// These functions return the axis-aligned rect that encloses the correctly
// clipped, transformed polygon.
static gfx::Rect MapEnclosingClippedRect(const gfx::Transform& transform,
const gfx::Rect& rect);
static gfx::RectF MapClippedRect(const gfx::Transform& transform,
const gfx::RectF& rect);
static gfx::Rect ProjectEnclosingClippedRect(const gfx::Transform& transform,
const gfx::Rect& rect);
static gfx::RectF ProjectClippedRect(const gfx::Transform& transform,
const gfx::RectF& rect);
// This function is only valid when the transform preserves 2d axis
// alignment and the resulting rect will not be clipped.
static gfx::Rect MapEnclosedRectWith2dAxisAlignedTransform(
const gfx::Transform& transform,
const gfx::Rect& rect);
// Returns an array of vertices that represent the clipped polygon. After
// returning, indexes from 0 to num_vertices_in_clipped_quad are valid in the
// clipped_quad array. Note that num_vertices_in_clipped_quad may be zero,
// which means the entire quad was clipped, and none of the vertices in the
// array are valid.
static bool MapClippedQuad3d(const gfx::Transform& transform,
const gfx::QuadF& src_quad,
gfx::Point3F clipped_quad[6],
int* num_vertices_in_clipped_quad);
static gfx::RectF ComputeEnclosingRectOfVertices(const gfx::PointF vertices[],
int num_vertices);
static gfx::RectF ComputeEnclosingClippedRect(
const HomogeneousCoordinate& h1,
const HomogeneousCoordinate& h2,
const HomogeneousCoordinate& h3,
const HomogeneousCoordinate& h4);
// NOTE: These functions do not do correct clipping against w = 0 plane, but
// they correctly detect the clipped condition via the boolean clipped.
static gfx::QuadF MapQuad(const gfx::Transform& transform,
const gfx::QuadF& quad,
bool* clipped);
static gfx::PointF MapPoint(const gfx::Transform& transform,
const gfx::PointF& point,
bool* clipped);
static gfx::PointF ProjectPoint(const gfx::Transform& transform,
const gfx::PointF& point,
bool* clipped);
// Identical to the above function, but coerces the homogeneous coordinate to
// a 3d rather than a 2d point.
static gfx::Point3F ProjectPoint3D(const gfx::Transform& transform,
const gfx::PointF& point,
bool* clipped);
static gfx::Vector2dF ComputeTransform2dScaleComponents(const gfx::Transform&,
float fallbackValue);
// Makes a rect that has the same relationship to input_outer_rect as
// scale_inner_rect has to scale_outer_rect. scale_inner_rect should be
// contained within scale_outer_rect, and likewise the rectangle that is
// returned will be within input_outer_rect at a similar relative, scaled
// position.
static gfx::RectF ScaleRectProportional(const gfx::RectF& input_outer_rect,
const gfx::RectF& scale_outer_rect,
const gfx::RectF& scale_inner_rect);
// Returns the smallest angle between the given two vectors in degrees.
// Neither vector is assumed to be normalized.
static float SmallestAngleBetweenVectors(const gfx::Vector2dF& v1,
const gfx::Vector2dF& v2);
// Projects the |source| vector onto |destination|. Neither vector is assumed
// to be normalized.
static gfx::Vector2dF ProjectVector(const gfx::Vector2dF& source,
const gfx::Vector2dF& destination);
// Conversion to value.
static std::unique_ptr<base::Value> AsValue(const gfx::Size& s);
static std::unique_ptr<base::Value> AsValue(const gfx::Rect& r);
static bool FromValue(const base::Value*, gfx::Rect* out_rect);
static std::unique_ptr<base::Value> AsValue(const gfx::PointF& q);
static void AddToTracedValue(const char* name,
const gfx::Size& s,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::SizeF& s,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::Rect& r,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::Point& q,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::PointF& q,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::Point3F&,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::Vector2d& v,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::Vector2dF& v,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::ScrollOffset& v,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::QuadF& q,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::RectF& rect,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::Transform& transform,
base::trace_event::TracedValue* res);
static void AddToTracedValue(const char* name,
const gfx::BoxF& box,
base::trace_event::TracedValue* res);
// Returns a base::Value representation of the floating point value.
// If the value is inf, returns max double/float representation.
static double AsDoubleSafely(double value);
static float AsFloatSafely(float value);
// Returns vector that x axis (1,0,0) transforms to under given transform.
static gfx::Vector3dF GetXAxis(const gfx::Transform& transform);
// Returns vector that y axis (0,1,0) transforms to under given transform.
static gfx::Vector3dF GetYAxis(const gfx::Transform& transform);
static bool IsFloatNearlyTheSame(float left, float right);
static bool IsNearlyTheSameForTesting(const gfx::PointF& l,
const gfx::PointF& r);
static bool IsNearlyTheSameForTesting(const gfx::Point3F& l,
const gfx::Point3F& r);
private:
template <typename T>
static T RoundUpInternal(T n, T mul) {
return (n > 0) ? ((n + mul - 1) / mul) * mul : (n / mul) * mul;
}
template <typename T>
static T RoundDownInternal(T n, T mul) {
return (n > 0) ? (n / mul) * mul : (n == 0) ? 0
: ((n - mul + 1) / mul) * mul;
}
};
class CC_BASE_EXPORT ScopedSubnormalFloatDisabler {
public:
ScopedSubnormalFloatDisabler();
~ScopedSubnormalFloatDisabler();
private:
#ifdef __SSE__
unsigned int orig_state_;
#endif
DISALLOW_COPY_AND_ASSIGN(ScopedSubnormalFloatDisabler);
};
} // namespace cc
#endif // CC_BASE_MATH_UTIL_H_