Notepad3/scintilla/src/Geometry.h
2021-07-02 16:48:15 +02:00

312 lines
8.9 KiB
C++

// Scintilla source code edit control
/** @file Geometry.h
** Classes and functions for geometric and colour calculations.
**/
// Copyright 2020 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.
#ifndef GEOMETRY_H
#define GEOMETRY_H
namespace Scintilla::Internal {
typedef double XYPOSITION;
typedef double XYACCUMULATOR;
/**
* A geometric point class.
* Point is similar to the Win32 POINT and GTK+ GdkPoint types.
*/
class Point {
public:
XYPOSITION x;
XYPOSITION y;
constexpr explicit Point(XYPOSITION x_=0, XYPOSITION y_=0) noexcept : x(x_), y(y_) {
}
static constexpr Point FromInts(int x_, int y_) noexcept {
return Point(static_cast<XYPOSITION>(x_), static_cast<XYPOSITION>(y_));
}
constexpr bool operator==(Point other) const noexcept {
return (x == other.x) && (y == other.y);
}
constexpr bool operator!=(Point other) const noexcept {
return (x != other.x) || (y != other.y);
}
constexpr Point operator+(Point other) const noexcept {
return Point(x + other.x, y + other.y);
}
constexpr Point operator-(Point other) const noexcept {
return Point(x - other.x, y - other.y);
}
// Other automatically defined methods (assignment, copy constructor, destructor) are fine
};
/**
* A geometric interval class.
*/
class Interval {
public:
XYPOSITION left;
XYPOSITION right;
constexpr bool operator==(const Interval &other) const noexcept {
return (left == other.left) && (right == other.right);
}
constexpr XYPOSITION Width() const noexcept { return right - left; }
constexpr bool Empty() const noexcept {
return Width() <= 0;
}
constexpr bool Intersects(Interval other) const noexcept {
return (right > other.left) && (left < other.right);
}
};
/**
* A geometric rectangle class.
* PRectangle is similar to Win32 RECT.
* PRectangles contain their top and left sides, but not their right and bottom sides.
*/
class PRectangle {
public:
XYPOSITION left;
XYPOSITION top;
XYPOSITION right;
XYPOSITION bottom;
constexpr explicit PRectangle(XYPOSITION left_=0, XYPOSITION top_=0, XYPOSITION right_=0, XYPOSITION bottom_ = 0) noexcept :
left(left_), top(top_), right(right_), bottom(bottom_) {
}
static constexpr PRectangle FromInts(int left_, int top_, int right_, int bottom_) noexcept {
return PRectangle(static_cast<XYPOSITION>(left_), static_cast<XYPOSITION>(top_),
static_cast<XYPOSITION>(right_), static_cast<XYPOSITION>(bottom_));
}
// Other automatically defined methods (assignment, copy constructor, destructor) are fine
constexpr bool operator==(const PRectangle &rc) const noexcept {
return (rc.left == left) && (rc.right == right) &&
(rc.top == top) && (rc.bottom == bottom);
}
constexpr bool Contains(Point pt) const noexcept {
return (pt.x >= left) && (pt.x <= right) &&
(pt.y >= top) && (pt.y <= bottom);
}
constexpr bool ContainsWholePixel(Point pt) const noexcept {
// Does the rectangle contain all of the pixel to left/below the point
return (pt.x >= left) && ((pt.x+1) <= right) &&
(pt.y >= top) && ((pt.y+1) <= bottom);
}
constexpr bool Contains(PRectangle rc) const noexcept {
return (rc.left >= left) && (rc.right <= right) &&
(rc.top >= top) && (rc.bottom <= bottom);
}
constexpr bool Intersects(PRectangle other) const noexcept {
return (right > other.left) && (left < other.right) &&
(bottom > other.top) && (top < other.bottom);
}
void Move(XYPOSITION xDelta, XYPOSITION yDelta) noexcept {
left += xDelta;
top += yDelta;
right += xDelta;
bottom += yDelta;
}
constexpr PRectangle Inset(XYPOSITION delta) const noexcept {
return PRectangle(left + delta, top + delta, right - delta, bottom - delta);
}
constexpr PRectangle Inset(Point delta) const noexcept {
return PRectangle(left + delta.x, top + delta.y, right - delta.x, bottom - delta.y);
}
constexpr Point Centre() const noexcept {
return Point((left + right) / 2, (top + bottom) / 2);
}
constexpr XYPOSITION Width() const noexcept { return right - left; }
constexpr XYPOSITION Height() const noexcept { return bottom - top; }
constexpr bool Empty() const noexcept {
return (Height() <= 0) || (Width() <= 0);
}
};
enum class Edge { left, top, bottom, right };
PRectangle Clamp(PRectangle rc, Edge edge, XYPOSITION position) noexcept;
PRectangle Side(PRectangle rc, Edge edge, XYPOSITION size) noexcept;
Interval Intersection(Interval a, Interval b) noexcept;
PRectangle Intersection(PRectangle rc, Interval horizontalBounds) noexcept;
Interval HorizontalBounds(PRectangle rc) noexcept;
XYPOSITION PixelAlign(XYPOSITION xy, int pixelDivisions) noexcept;
XYPOSITION PixelAlignFloor(XYPOSITION xy, int pixelDivisions) noexcept;
Point PixelAlign(const Point &pt, int pixelDivisions) noexcept;
PRectangle PixelAlign(const PRectangle &rc, int pixelDivisions) noexcept;
PRectangle PixelAlignOutside(const PRectangle &rc, int pixelDivisions) noexcept;
/**
* Holds an RGBA colour with 8 bits for each component.
*/
constexpr const float componentMaximum = 255.0f;
class ColourRGBA {
int co;
constexpr static unsigned int Mixed(unsigned char a, unsigned char b, double proportion) noexcept {
return static_cast<unsigned int>(a + proportion * (b - a));
}
public:
constexpr explicit ColourRGBA(int co_ = 0) noexcept : co(co_) {
}
constexpr ColourRGBA(unsigned int red, unsigned int green, unsigned int blue, unsigned int alpha=0xff) noexcept :
ColourRGBA(red | (green << 8) | (blue << 16) | (alpha << 24)) {
}
constexpr ColourRGBA(ColourRGBA cd, unsigned int alpha) noexcept :
ColourRGBA(cd.OpaqueRGB() | (alpha << 24)) {
}
static constexpr ColourRGBA FromRGB(int co_) noexcept {
return ColourRGBA(co_ | (0xffu << 24));
}
static constexpr ColourRGBA FromIpRGB(intptr_t co_) noexcept {
return ColourRGBA(static_cast<int>(co_) | (0xffu << 24));
}
constexpr ColourRGBA WithoutAlpha() const noexcept {
return ColourRGBA(co & 0xffffff);
}
constexpr ColourRGBA Opaque() const noexcept {
return ColourRGBA(co | (0xffu << 24));
}
constexpr int AsInteger() const noexcept {
return co;
}
constexpr int OpaqueRGB() const noexcept {
return co & 0xffffff;
}
// Red, green and blue values as bytes 0..255
constexpr unsigned char GetRed() const noexcept {
return co & 0xff;
}
constexpr unsigned char GetGreen() const noexcept {
return (co >> 8) & 0xff;
}
constexpr unsigned char GetBlue() const noexcept {
return (co >> 16) & 0xff;
}
constexpr unsigned char GetAlpha() const noexcept {
return (co >> 24) & 0xff;
}
// Red, green, blue, and alpha values as float 0..1.0
constexpr float GetRedComponent() const noexcept {
return GetRed() / componentMaximum;
}
constexpr float GetGreenComponent() const noexcept {
return GetGreen() / componentMaximum;
}
constexpr float GetBlueComponent() const noexcept {
return GetBlue() / componentMaximum;
}
constexpr float GetAlphaComponent() const noexcept {
return GetAlpha() / componentMaximum;
}
constexpr bool operator==(const ColourRGBA &other) const noexcept {
return co == other.co;
}
constexpr bool IsOpaque() const noexcept {
return GetAlpha() == 0xff;
}
constexpr ColourRGBA MixedWith(ColourRGBA other) const noexcept {
const unsigned int red = (GetRed() + other.GetRed()) / 2;
const unsigned int green = (GetGreen() + other.GetGreen()) / 2;
const unsigned int blue = (GetBlue() + other.GetBlue()) / 2;
const unsigned int alpha = (GetAlpha() + other.GetAlpha()) / 2;
return ColourRGBA(red, green, blue, alpha);
}
constexpr ColourRGBA MixedWith(ColourRGBA other, double proportion) const noexcept {
return ColourRGBA(
Mixed(GetRed(), other.GetRed(), proportion),
Mixed(GetGreen(), other.GetGreen(), proportion),
Mixed(GetBlue(), other.GetBlue(), proportion),
Mixed(GetAlpha(), other.GetAlpha(), proportion));
}
};
/**
* Holds an RGBA colour and stroke width to stroke a shape.
*/
class Stroke {
public:
ColourRGBA colour;
XYPOSITION width;
constexpr Stroke(ColourRGBA colour_, XYPOSITION width_=1.0) noexcept :
colour(colour_), width(width_) {
}
constexpr float WidthF() const noexcept {
return static_cast<float>(width);
}
};
/**
* Holds an RGBA colour to fill a shape.
*/
class Fill {
public:
ColourRGBA colour;
constexpr Fill(ColourRGBA colour_) noexcept :
colour(colour_) {
}
};
/**
* Holds a pair of RGBA colours and stroke width to fill and stroke a shape.
*/
class FillStroke {
public:
Fill fill;
Stroke stroke;
constexpr FillStroke(ColourRGBA colourFill_, ColourRGBA colourStroke_, XYPOSITION widthStroke_=1.0) noexcept :
fill(colourFill_), stroke(colourStroke_, widthStroke_) {
}
constexpr FillStroke(ColourRGBA colourBoth, XYPOSITION widthStroke_=1.0) noexcept :
fill(colourBoth), stroke(colourBoth, widthStroke_) {
}
};
/**
* Holds an element of a gradient with an RGBA colour and a relative position.
*/
class ColourStop {
public:
XYPOSITION position;
ColourRGBA colour;
constexpr ColourStop(XYPOSITION position_, ColourRGBA colour_) noexcept :
position(position_), colour(colour_) {
}
};
}
#endif