twitchapon-anim

colorm.go (3688B)

---

 // Copyright 2014 Hajime Hoshi
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 package ebiten
 
 import (
 	"fmt"
 
 	"image/color"
 
 	"github.com/hajimehoshi/ebiten/v2/internal/affine"
 )
 
 // ColorMDim is a dimension of a ColorM.
 const ColorMDim = affine.ColorMDim
 
 // A ColorM represents a matrix to transform coloring when rendering an image.
 //
 // A ColorM is applied to the straight alpha color
 // while an Image's pixels' format is alpha premultiplied.
 // Before applying a matrix, a color is un-multiplied, and after applying the matrix,
 // the color is multiplied again.
 //
 // The initial value is identity.
 type ColorM struct {
 	impl *affine.ColorM
 
 	_ [0]func() // Marks as non-comparable.
 }
 
 // String returns a string representation of ColorM.
 func (c *ColorM) String() string {
 	b, t := c.impl.UnsafeElements()
 	return fmt.Sprintf("[[%f, %f, %f, %f, %f], [%f, %f, %f, %f, %f], [%f, %f, %f, %f, %f], [%f, %f, %f, %f, %f]]",
 		b[0], b[4], b[8], b[12], t[0],
 		b[1], b[5], b[9], b[13], t[1],
 		b[2], b[6], b[10], b[14], t[2],
 		b[3], b[7], b[11], b[15], t[3])
 }
 
 // Reset resets the ColorM as identity.
 func (c *ColorM) Reset() {
 	c.impl = nil
 }
 
 // Apply pre-multiplies a vector (r, g, b, a, 1) by the matrix
 // where r, g, b, and a are clr's values in straight-alpha format.
 // In other words, Apply calculates ColorM * (r, g, b, a, 1)^T.
 func (c *ColorM) Apply(clr color.Color) color.Color {
 	return c.impl.Apply(clr)
 }
 
 // Concat multiplies a color matrix with the other color matrix.
 // This is same as muptiplying the matrix other and the matrix c in this order.
 func (c *ColorM) Concat(other ColorM) {
 	c.impl = c.impl.Concat(other.impl)
 }
 
 // Scale scales the matrix by (r, g, b, a).
 func (c *ColorM) Scale(r, g, b, a float64) {
 	c.impl = c.impl.Scale(float32(r), float32(g), float32(b), float32(a))
 }
 
 // Translate translates the matrix by (r, g, b, a).
 func (c *ColorM) Translate(r, g, b, a float64) {
 	c.impl = c.impl.Translate(float32(r), float32(g), float32(b), float32(a))
 }
 
 // RotateHue rotates the hue.
 // theta represents rotating angle in radian.
 func (c *ColorM) RotateHue(theta float64) {
 	c.ChangeHSV(theta, 1, 1)
 }
 
 // ChangeHSV changes HSV (Hue-Saturation-Value) values.
 // hueTheta is a radian value to rotate hue.
 // saturationScale is a value to scale saturation.
 // valueScale is a value to scale value (a.k.a. brightness).
 //
 // This conversion uses RGB to/from YCrCb conversion.
 func (c *ColorM) ChangeHSV(hueTheta float64, saturationScale float64, valueScale float64) {
 	c.impl = c.impl.ChangeHSV(hueTheta, float32(saturationScale), float32(valueScale))
 }
 
 // Element returns a value of a matrix at (i, j).
 func (c *ColorM) Element(i, j int) float64 {
 	return float64(c.impl.Element(i, j))
 }
 
 // SetElement sets an element at (i, j).
 func (c *ColorM) SetElement(i, j int, element float64) {
 	c.impl = c.impl.SetElement(i, j, float32(element))
 }
 
 // IsInvertible returns a boolean value indicating
 // whether the matrix c is invertible or not.
 func (c *ColorM) IsInvertible() bool {
 	return c.impl.IsInvertible()
 }
 
 // Invert inverts the matrix.
 // If c is not invertible, Invert panics.
 func (c *ColorM) Invert() {
 	c.impl = c.impl.Invert()
 }