Part 1 of cc/ directory shuffles: base

cc/math_util.h

-// 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_MATH_UTIL_H_
-#define CC_MATH_UTIL_H_
-
-#include <cmath>
-
-#include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
-#include "cc/cc_export.h"
-#include "ui/gfx/point_f.h"
-#include "ui/gfx/point3_f.h"
-#include "ui/gfx/size.h"
-#include "ui/gfx/transform.h"
-
-namespace base {
-class Value;
-}
-
-namespace gfx {
-class QuadF;
-class Rect;
-class RectF;
-class Transform;
-class Vector2dF;
-}
-
-namespace cc {
-
-struct HomogeneousCoordinate {
-    HomogeneousCoordinate(double newX, double newY, double newZ, double newW)
-        : x(newX)
-        , y(newY)
-        , z(newZ)
-        , w(newW)
-    {
-    }
-
-    bool shouldBeClipped() const
-    {
-        return w <= 0;
-    }
-
-    gfx::PointF cartesianPoint2d() const
-    {
-        if (w == 1)
-            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);
-        double invW = 1.0 / w;
-        return gfx::PointF(x * invW, y * invW);
-    }
-
-    gfx::Point3F cartesianPoint3d() const
-    {
-        if (w == 1)
-            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);
-        double invW = 1.0 / w;
-        return gfx::Point3F(x * invW, y * invW, z * invW);
-    }
-
-    double x;
-    double y;
-    double z;
-    double w;
-};
-
-class CC_EXPORT MathUtil {
-public:
-    static const double PI_DOUBLE;
-    static const float PI_FLOAT;
-    static const double EPSILON;
-
-    static double Deg2Rad(double deg)  { return deg * PI_DOUBLE / 180; }
-    static double Rad2Deg(double rad)  { return rad * 180 / PI_DOUBLE; }
-
-    static float Deg2Rad(float deg)  { return deg * PI_FLOAT / 180; }
-    static float Rad2Deg(float rad)  { return rad * 180 / PI_FLOAT; }
-
-    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); }
-
-    // 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 mapClippedRect(const gfx::Transform&, const gfx::Rect&);
-    static gfx::RectF mapClippedRect(const gfx::Transform&, const gfx::RectF&);
-    static gfx::RectF projectClippedRect(const gfx::Transform&, const gfx::RectF&);
-
-    // Returns an array of vertices that represent the clipped polygon. After returning, indexes from
-    // 0 to numVerticesInClippedQuad are valid in the clippedQuad array. Note that
-    // numVerticesInClippedQuad may be zero, which means the entire quad was clipped, and
-    // none of the vertices in the array are valid.
-    static void mapClippedQuad(const gfx::Transform&, const gfx::QuadF& srcQuad, gfx::PointF clippedQuad[8], int& numVerticesInClippedQuad);
-
-    static gfx::RectF computeEnclosingRectOfVertices(gfx::PointF vertices[], int numVertices);
-    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&, const gfx::QuadF&, bool& clipped);
-    static gfx::PointF mapPoint(const gfx::Transform&, const gfx::PointF&, bool& clipped);
-    static gfx::Point3F mapPoint(const gfx::Transform&, const gfx::Point3F&, bool& clipped);
-    static gfx::QuadF projectQuad(const gfx::Transform&, const gfx::QuadF&, bool& clipped);
-    static gfx::PointF projectPoint(const gfx::Transform&, const gfx::PointF&, bool& clipped);
-
-    static gfx::Vector2dF computeTransform2dScaleComponents(const gfx::Transform&, float fallbackValue);
-
-    // Returns the smallest angle between the given two vectors in degrees. Neither vector is
-    // assumed to be normalized.
-    static float smallestAngleBetweenVectors(gfx::Vector2dF, gfx::Vector2dF);
-
-    // Projects the |source| vector onto |destination|. Neither vector is assumed to be normalized.
-    static gfx::Vector2dF projectVector(gfx::Vector2dF source, gfx::Vector2dF destination);
-
-    // Conversion to value.
-    static scoped_ptr<base::Value> asValue(gfx::Size s);
-    static scoped_ptr<base::Value> asValue(gfx::PointF q);
-    static scoped_ptr<base::Value> asValue(gfx::QuadF q);
-
-    // Returns a base::Value representation of the floating point value.
-    // If the value is inf, returns max double/float representation.
-    static scoped_ptr<base::Value> asValueSafely(double value);
-    static scoped_ptr<base::Value> asValueSafely(float value);
-
-};
-
-} // namespace cc
-
-#endif  // CC_MATH_UTIL_H_