mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-10 13:07:26 +01:00
126 lines
3.1 KiB
Go
126 lines
3.1 KiB
Go
// 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 affine
|
|
|
|
import (
|
|
"math"
|
|
)
|
|
|
|
// GeoMDim is a dimension of a GeoM.
|
|
const GeoMDim = 3
|
|
|
|
func geoMValueString(values [GeoMDim - 1][GeoMDim]float64) string {
|
|
b := make([]uint8, 0, (GeoMDim-1)*(GeoMDim)*8)
|
|
for i := 0; i < GeoMDim-1; i++ {
|
|
for j := 0; j < GeoMDim; j++ {
|
|
b = append(b, uint64ToBytes(math.Float64bits(values[i][j]))...)
|
|
}
|
|
}
|
|
return string(b)
|
|
}
|
|
|
|
// A GeoM represents a matrix to transform geometry when rendering an image.
|
|
//
|
|
// The initial value is identity.
|
|
type GeoM struct {
|
|
// When values is empty, this matrix is identity.
|
|
values string
|
|
}
|
|
|
|
func (g *GeoM) dim() int {
|
|
return GeoMDim
|
|
}
|
|
|
|
// Element returns a value of a matrix at (i, j).
|
|
func (g *GeoM) Element(i, j int) float64 {
|
|
return element(g.values, GeoMDim, i, j)
|
|
}
|
|
|
|
// SetElement sets an element at (i, j).
|
|
func (g *GeoM) SetElement(i, j int, element float64) {
|
|
g.values = setElement(g.values, GeoMDim, i, j, element)
|
|
}
|
|
|
|
// Concat multiplies a geometry matrix with the other geometry matrix.
|
|
// This is same as muptiplying the matrix other and the matrix g in this order.
|
|
func (g *GeoM) Concat(other GeoM) {
|
|
result := GeoM{}
|
|
mul(&other, g, &result)
|
|
*g = result
|
|
}
|
|
|
|
// Add is deprecated.
|
|
func (g *GeoM) Add(other GeoM) {
|
|
result := GeoM{}
|
|
add(&other, g, &result)
|
|
*g = result
|
|
}
|
|
|
|
// Scale scales the matrix by (x, y).
|
|
func (g *GeoM) Scale(x, y float64) {
|
|
for i := 0; i < GeoMDim; i++ {
|
|
g.SetElement(0, i, g.Element(0, i)*x)
|
|
g.SetElement(1, i, g.Element(1, i)*y)
|
|
}
|
|
}
|
|
|
|
// Translate translates the matrix by (x, y).
|
|
func (g *GeoM) Translate(tx, ty float64) {
|
|
g.SetElement(0, 2, g.Element(0, 2)+tx)
|
|
g.SetElement(1, 2, g.Element(1, 2)+ty)
|
|
}
|
|
|
|
// Rotate rotates the matrix by theta.
|
|
func (g *GeoM) Rotate(theta float64) {
|
|
sin, cos := math.Sincos(theta)
|
|
g.Concat(GeoM{
|
|
values: geoMValueString([GeoMDim - 1][GeoMDim]float64{
|
|
{cos, -sin, 0},
|
|
{sin, cos, 0},
|
|
}),
|
|
})
|
|
}
|
|
|
|
// ScaleGeo is deprecated as of 1.2.0-alpha. Use Scale instead.
|
|
func ScaleGeo(x, y float64) GeoM {
|
|
return GeoM{
|
|
values: geoMValueString([GeoMDim - 1][GeoMDim]float64{
|
|
{x, 0, 0},
|
|
{0, y, 0},
|
|
}),
|
|
}
|
|
}
|
|
|
|
// TranslateGeo is deprecated as of 1.2.0-alpha. Use Translate instead.
|
|
func TranslateGeo(tx, ty float64) GeoM {
|
|
return GeoM{
|
|
values: geoMValueString([GeoMDim - 1][GeoMDim]float64{
|
|
{1, 0, tx},
|
|
{0, 1, ty},
|
|
}),
|
|
}
|
|
}
|
|
|
|
// RotateGeo is deprecated as of 1.2.0-alpha. Use Rotate instead.
|
|
func RotateGeo(theta float64) GeoM {
|
|
sin, cos := math.Sincos(theta)
|
|
return GeoM{
|
|
values: geoMValueString([GeoMDim - 1][GeoMDim]float64{
|
|
{cos, -sin, 0},
|
|
{sin, cos, 0},
|
|
}),
|
|
}
|
|
}
|