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Add perspective func+fix LookAt

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bloeys
2021-11-09 09:55:24 +04:00
parent d1a4f5ba7c
commit 175d05420c
1 changed files with 14 additions and 1 deletions
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15
gglm/transform.go
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@ -2,6 +2,7 @@ package gglm
import ( import (
"fmt" "fmt"
"math"
) )
var _ Mat = &TrMat{} var _ Mat = &TrMat{}
@ -110,12 +111,24 @@ func LookAt(pos, targetPos, worldUp *Vec3) *TrMat {
{right.Data[0], up.Data[0], forward.Data[0], 0}, {right.Data[0], up.Data[0], forward.Data[0], 0},
{right.Data[1], up.Data[1], forward.Data[1], 0}, {right.Data[1], up.Data[1], forward.Data[1], 0},
{right.Data[2], up.Data[2], forward.Data[2], 0}, {right.Data[2], up.Data[2], forward.Data[2], 0},
{-DotVec3(pos, right), -DotVec3(pos, up), -DotVec3(pos, forward), 1}, {-DotVec3(pos, right), -DotVec3(pos, up), DotVec3(pos, forward), 1},
}, },
}, },
} }
} }
func Perspective(fov, aspectRatio, nearClip, farClip float32) *Mat4 {
halfFovTan := float32(math.Tan(float64(fov * 0.5)))
return &Mat4{
Data: [4][4]float32{
{1 / (aspectRatio * halfFovTan), 0, 0, 0},
{0, 1 / halfFovTan, 0, 0},
{0, 0, -(nearClip + farClip) / (farClip - nearClip), -1},
{0, 0, -(2 * farClip * nearClip) / (farClip - nearClip), 0},
},
}
}
func NewTrMatId() *TrMat { func NewTrMatId() *TrMat {
return &TrMat{ return &TrMat{
Mat4: *NewMat4Id(), Mat4: *NewMat4Id(),