blob: fd9855f8bbbfa4fdc43cc4c028bf9e676bbe119b [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 #include #include #include "base/logging.h" #include "build/build_config.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: // Returns true if rounded up value does not overflow, false otherwise. template static bool VerifyRoundup(T n, T mul) { return mul && (n <= (std::numeric_limits::max() - (std::numeric_limits::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 static T UncheckedRoundUp(T n, T mul) { static_assert(std::numeric_limits::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 static T CheckedRoundUp(T n, T mul) { static_assert(std::numeric_limits::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 static bool VerifyRoundDown(T n, T mul) { return mul && (n >= (std::numeric_limits::min() - (std::numeric_limits::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 static T UncheckedRoundDown(T n, T mul) { static_assert(std::numeric_limits::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 static T CheckedRoundDown(T n, T mul) { static_assert(std::numeric_limits::is_integer, "T must be an integer type"); CHECK(VerifyRoundDown(n, mul)); return RoundDownInternal(n, mul); } template static bool IsWithinEpsilon(T a, T b) { return std::abs(a - b) < std::numeric_limits::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::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); static gfx::Vector2dF ComputeTransform2dScaleComponents(const gfx::Transform&, float fallbackValue); // Returns an approximate max scale value of the transform even if it has // perspective. Prefer to use ComputeTransform2dScaleComponents if there is no // perspective, since it can produce more accurate results. static float ComputeApproximateMaxScale(const gfx::Transform& transform); // 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 AsValue(const gfx::Size& s); static std::unique_ptr AsValue(const gfx::Rect& r); static bool FromValue(const base::Value*, gfx::Rect* out_rect); static std::unique_ptr 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 static T RoundUpInternal(T n, T mul) { return (n > 0) ? ((n + mul - 1) / mul) * mul : (n / mul) * mul; } template 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: #if defined(ARCH_CPU_X86_FAMILY) unsigned int orig_state_; #endif DISALLOW_COPY_AND_ASSIGN(ScopedSubnormalFloatDisabler); }; } // namespace cc #endif // CC_BASE_MATH_UTIL_H_