| // 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 <limits> |
| #include <memory> |
| #include <vector> |
| |
| #include "base/check.h" |
| #include "base/cxx17_backports.h" |
| #include "build/build_config.h" |
| #include "cc/base/base_export.h" |
| #include "third_party/skia/include/core/SkM44.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/rounded_corners_f.h" |
| #include "ui/gfx/geometry/size.h" |
| #include "ui/gfx/geometry/transform.h" |
| #include "ui/gfx/geometry/vector2d_f.h" |
| |
| namespace base { |
| class Value; |
| namespace trace_event { |
| class TracedValue; |
| } |
| } // namespace base |
| |
| namespace gfx { |
| class QuadF; |
| class Rect; |
| class RectF; |
| class RRectF; |
| class SizeF; |
| class Transform; |
| class Vector2dF; |
| class Vector2d; |
| class Vector3dF; |
| class LinearGradient; |
| } // namespace gfx |
| |
| namespace cc { |
| |
| struct HomogeneousCoordinate { |
| // This needs to be big enough that it does not incorrectly clip the projected |
| // coordinate. For local to device projection, this must be bigger than the |
| // expected size of a display. For inverse projection, this is hopefully |
| // larger than the required local layer size of page content. If it is made |
| // too big then bounding box calculations based on projected coordinates can |
| // lose precision and lead to incorrect page rendering. |
| static constexpr float kInfiniteCoordinate = 1000000.0f; |
| |
| HomogeneousCoordinate(SkScalar x, SkScalar y, SkScalar z, SkScalar 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_Scalar1) |
| 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()); |
| SkScalar inv_w = SK_Scalar1 / w(); |
| // However, w may be close to 0 and we lose precision on our geometry |
| // calculations if we allow scaling to extremely large values. |
| return gfx::PointF(base::clamp(x() * inv_w, -kInfiniteCoordinate, |
| float{kInfiniteCoordinate}), |
| base::clamp(y() * inv_w, -kInfiniteCoordinate, |
| float{kInfiniteCoordinate})); |
| } |
| |
| gfx::Point3F CartesianPoint3d() const { |
| if (w() == SK_Scalar1) |
| 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()); |
| SkScalar inv_w = SK_Scalar1 / w(); |
| // However, w may be close to 0 and we lose precision on our geometry |
| // calculations if we allow scaling to extremely large values. |
| return gfx::Point3F(base::clamp(x() * inv_w, -kInfiniteCoordinate, |
| float{kInfiniteCoordinate}), |
| base::clamp(y() * inv_w, -kInfiniteCoordinate, |
| float{kInfiniteCoordinate}), |
| base::clamp(z() * inv_w, -kInfiniteCoordinate, |
| float{kInfiniteCoordinate})); |
| } |
| |
| gfx::Point3F CartesianPoint3dUnclamped() const { |
| if (w() == SK_Scalar1) |
| 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()); |
| SkScalar inv_w = SK_Scalar1 / w(); |
| // However, w may be close to 0 and we lose precision on our geometry |
| // calculations if we allow scaling to extremely large values. |
| return gfx::Point3F(x() * inv_w, y() * inv_w, z() * inv_w); |
| } |
| |
| SkScalar x() const { return vec[0]; } |
| SkScalar y() const { return vec[1]; } |
| SkScalar z() const { return vec[2]; } |
| SkScalar w() const { return vec[3]; } |
| |
| SkScalar vec[4]; |
| }; |
| |
| class CC_BASE_EXPORT MathUtil { |
| public: |
| // 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"); |
| 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"); |
| 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 bool IsWithinEpsilon(T a, T b) { |
| return std::abs(a - b) < std::numeric_limits<T>::epsilon(); |
| } |
| |
| // 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::Rect MapEnclosingClippedRectIgnoringError( |
| const gfx::Transform& transform, |
| const gfx::Rect& rect, |
| float ignore_error); |
| 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); |
| |
| // Map device space quad to local space. Device_transform has no 3d |
| // component since it was flattened, so we don't need to project. We should |
| // have already checked that the transform was invertible before this call. |
| static gfx::QuadF InverseMapQuadToLocalSpace( |
| const gfx::Transform& device_transform, |
| const gfx::QuadF& device_quad); |
| |
| // 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); |
| |
| // 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); |
| |
| static bool FromValue(const base::Value*, gfx::Rect* out_rect); |
| |
| 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::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); |
| static void AddToTracedValue(const char* name, |
| const gfx::RRectF& rect, |
| base::trace_event::TracedValue* res); |
| static void AddCornerRadiiToTracedValue(const char* name, |
| const gfx::RRectF& rect, |
| base::trace_event::TracedValue* res); |
| static void AddToTracedValue(const char* name, |
| const gfx::LinearGradient& gradient, |
| 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); |
| |
| // Helper functions for migration from SkMatrix->SkM44. It may make sense to |
| // move these to skia itself at some point. |
| static bool SkM44HasPerspective(const SkM44& m); |
| static bool SkM44Is2D(const SkM44& m); |
| static bool SkM44Preserves2DAxisAlignment(const SkM44& m); |
| |
| 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(const ScopedSubnormalFloatDisabler&) = delete; |
| ~ScopedSubnormalFloatDisabler(); |
| |
| ScopedSubnormalFloatDisabler& operator=(const ScopedSubnormalFloatDisabler&) = |
| delete; |
| |
| #if defined(ARCH_CPU_X86_FAMILY) |
| private: |
| unsigned int orig_state_; |
| #endif |
| }; |
| |
| } // namespace cc |
| |
| #endif // CC_BASE_MATH_UTIL_H_ |