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kooparse merged 3 commits into from
Jul 28, 2026
Merged

Separate -1 to 1 and 0 to 1 versions of perspective matrices #78

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73d6575
Separate -1 to 1 and 0 to 1 versions of perspective matrices
Nairou Jul 19, 2026
c40617a
Update README
Nairou Jul 20, 2026
36222ef
Merge branch 'main' into perspective
kooparse Jul 28, 2026
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109 changes: 56 additions & 53 deletions README.md
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Expand Up @@ -34,29 +34,30 @@ pub fn main () void {

### Aliases

| Type | Description |
| ------------ | ---------------------------------------- |
| Vec2 | Two dimensional vector for `f32` |
| Vec2_f64 | Two dimensional vector for `f64` |
| Vec2_i32 | Two dimensional vector for `i32` |
| Vec2_usize | Two dimensional vector for `usize` |
| Vec3 | Three dimensional vector for `f32` |
| Vec3_f64 | Three dimensional vector for `f64` |
| Vec3_i32 | Three dimensional vector for `i32` |
| Vec3_usize | Three dimensional vector for `usize` |
| Vec4 | Four dimensional vector for `f32` |
| Vec4_f64 | Four dimensional vector for `f64` |
| Vec4_i32 | Four dimensional vector for `i32` |
| Vec4_usize | Four dimensional vector for `usize` |
| Mat3 | 3x3 matrix for `f32` |
| Mat3_f64 | 3x3 matrix for `f64` |
| Mat4 | 4x4 matrix for `f32` |
| Mat4_f64 | 4x4 matrix for `f64` |
| Quat | Quaternion for `f32` |
| Quat_f64 | Quaternion for `f64` |
| perspective | Perspective function for `f32` 4x4 mat4 |
| orthographic | Orthographic function for `f32` 4x4 mat4 |
| lookAt | LookAt function for `f32` 4x4 mat4 |
| Type | Description |
| -------------------- | --------------------------------------------------------------------- |
| Vec2 | Two dimensional vector for `f32` |
| Vec2_f64 | Two dimensional vector for `f64` |
| Vec2_i32 | Two dimensional vector for `i32` |
| Vec2_usize | Two dimensional vector for `usize` |
| Vec3 | Three dimensional vector for `f32` |
| Vec3_f64 | Three dimensional vector for `f64` |
| Vec3_i32 | Three dimensional vector for `i32` |
| Vec3_usize | Three dimensional vector for `usize` |
| Vec4 | Four dimensional vector for `f32` |
| Vec4_f64 | Four dimensional vector for `f64` |
| Vec4_i32 | Four dimensional vector for `i32` |
| Vec4_usize | Four dimensional vector for `usize` |
| Mat3 | 3x3 matrix for `f32` |
| Mat3_f64 | 3x3 matrix for `f64` |
| Mat4 | 4x4 matrix for `f32` |
| Mat4_f64 | 4x4 matrix for `f64` |
| Quat | Quaternion for `f32` |
| Quat_f64 | Quaternion for `f64` |
| perspective | Perspective function for `f32` 4x4 mat4 with -1 to 1 depth |
| perspectiveReversedZ | Reversed-Z perspective function for `f32` 4x4 mat4 with -1 to 1 depth |
| orthographic | Orthographic function for `f32` 4x4 mat4 |
| lookAt | LookAt function for `f32` 4x4 mat4 |

### Vectors

Expand Down Expand Up @@ -105,36 +106,38 @@ pub fn main () void {

Note: All matrices are column-major.

| Methods | Description |
| -------------------- | ------------------------------------------------------------------------------------- |
| identity | Construct an identity matrix |
| set | Set all matrix values to given value |
| fromSlice | Construct new matrix from given slice of data |
| getSlice | Return the inner data as a slice |
| transpose | Return the transpose matrix |
| negate | Scale all components by -1 |
| cast | Cast a type to another type |
| eql | Return `true` if two matrices are equals |
| mulByVec4 | Multiply a given vec4 by matrix (only for mat4) |
| fromTranslate | Construct a translation matrix |
| translate | Construct a translation from the given matrix according to given axis (vec3) |
| fromRotation | Construct a rotation matrix |
| fromEulerAngles | Construct a rotation matrix from pitch/yaw/roll in degrees (X _ Y _ Z) |
| rotate | Construct a rotation from the given matrix according to given axis (vec3) |
| fromScale | Construct a scale matrix |
| scale | Construct a scale from the given matrix according to given axis (vec3) |
| extractTranslation | Return a vector with proper translation |
| orthoNormalize | Ortho normalize the given matrix. |
| extractEulerAngles | Return a vector with Euler angles in degrees (pitch/yaw/roll) |
| extractScale | Return a vector with proper scale |
| perspective | Construct a perspective matrix from given fovy, aspect ratio, near/far inputs |
| perspectiveReversedZ | Construct a perspective matrix with reverse Z and infinite far plane. |
| orthographic | Construct an orthographic matrix from given left, right, bottom, top, near/far inputs |
| lookAt | Construct a right-handed lookAt matrix from given position (eye) and target |
| mul | Multiply two matrices |
| inv | Inverse the given matrix |
| recompose | Return mat4 matrix from given `translation`, `rotation` and `scale` components |
| decompose | Return components `translation`, `rotation` and `scale` from given 4x4 matrix. |
| Methods | Description |
| ------------------------------- | ------------------------------------------------------------------------------------------------------- |
| identity | Construct an identity matrix |
| set | Set all matrix values to given value |
| fromSlice | Construct new matrix from given slice of data |
| getSlice | Return the inner data as a slice |
| transpose | Return the transpose matrix |
| negate | Scale all components by -1 |
| cast | Cast a type to another type |
| eql | Return `true` if two matrices are equals |
| mulByVec4 | Multiply a given vec4 by matrix (only for mat4) |
| fromTranslate | Construct a translation matrix |
| translate | Construct a translation from the given matrix according to given axis (vec3) |
| fromRotation | Construct a rotation matrix |
| fromEulerAngles | Construct a rotation matrix from pitch/yaw/roll in degrees (X _ Y _ Z) |
| rotate | Construct a rotation from the given matrix according to given axis (vec3) |
| fromScale | Construct a scale matrix |
| scale | Construct a scale from the given matrix according to given axis (vec3) |
| extractTranslation | Return a vector with proper translation |
| orthoNormalize | Ortho normalize the given matrix. |
| extractEulerAngles | Return a vector with Euler angles in degrees (pitch/yaw/roll) |
| extractScale | Return a vector with proper scale |
| perspectiveNegativeOne | Construct a perspective matrix from given fovy, aspect ratio, near/far inputs, with -1 to 1 depth range |
| perspectiveZeroOne | Construct a perspective matrix from given fovy, aspect ratio, near/far inputs, with 0 to 1 depth range |
| perspectiveReversedZNegativeOne | Construct a perspective matrix with reverse Z and infinite far plane, with -1 to 1 depth range |
| perspectiveReversedZZeroOne | Construct a perspective matrix with reverse Z and infinite far plane, with 0 to 1 depth range |
| orthographic | Construct an orthographic matrix from given left, right, bottom, top, near/far inputs |
| lookAt | Construct a right-handed lookAt matrix from given position (eye) and target |
| mul | Multiply two matrices |
| inv | Inverse the given matrix |
| recompose | Return mat4 matrix from given `translation`, `rotation` and `scale` components |
| decompose | Return components `translation`, `rotation` and `scale` from given 4x4 matrix. |

### Quaternions

Expand Down
46 changes: 42 additions & 4 deletions src/mat4.zig
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Expand Up @@ -264,10 +264,14 @@ pub fn Mat4x4(comptime T: type) type {
return Vector3.new(scale_x.length(), scale_y.length(), scale_z.length());
}

/// Construct a perspective 4x4 matrix.
// Use depth -1 to 1 for perspective matrix by default, to match OpenGL defaults
pub const perspective = perspectiveNegativeOne;
pub const perspectiveReversedZ = perspectiveReversedZNegativeOne;

/// Construct a perspective 4x4 matrix, with a depth from -1 to 1.
/// Note: Field of view is given in degrees.
/// Also for more details https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/gluPerspective.xml.
pub fn perspective(fovy_in_degrees: T, aspect_ratio: T, z_near: T, z_far: T) Self {
pub fn perspectiveNegativeOne(fovy_in_degrees: T, aspect_ratio: T, z_near: T, z_far: T) Self {
const f = 1 / @tan(root.toRadians(fovy_in_degrees) * 0.5);
const nf = 1 / (z_near - z_far);

Expand All @@ -281,11 +285,45 @@ pub fn Mat4x4(comptime T: type) type {
};
}

/// Construct a perspective 4x4 matrix with reverse Z and infinite far plane.
/// Construct a perspective 4x4 matrix, with a depth from 0 to 1.
/// Note: Field of view is given in degrees.
/// Also for more details https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/gluPerspective.xml.
pub fn perspectiveZeroOne(fovy_in_degrees: T, aspect_ratio: T, z_near: T, z_far: T) Self {
const f = 1 / @tan(root.toRadians(fovy_in_degrees) * 0.5);
const nf = 1 / (z_near - z_far);

return .{
.data = .{
.{ f / aspect_ratio, 0, 0, 0 },
.{ 0, f, 0, 0 },
.{ 0, 0, z_far * nf, -1 },
.{ 0, 0, z_near * z_far * nf, 0 },
},
};
}

/// Construct a perspective 4x4 matrix with reverse Z and infinite far plane, with a depth from -1 to 1.
/// Note: Field of view is given in degrees.
/// Also for more details https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/gluPerspective.xml.
/// For Reversed-Z details https://nlguillemot.wordpress.com/2016/12/07/reversed-z-in-opengl/
pub fn perspectiveReversedZNegativeOne(fovy_in_degrees: T, aspect_ratio: T, z_near: T) Self {
const f = 1 / @tan(root.toRadians(fovy_in_degrees) * 0.5);

return .{
.data = .{
.{ f / aspect_ratio, 0, 0, 0 },
.{ 0, f, 0, 0 },
.{ 0, 0, 1, -1 },
.{ 0, 0, 2 * z_near, 0 },
},
};
}

/// Construct a perspective 4x4 matrix with reverse Z and infinite far plane, with a depth from 0 to 1.
/// Note: Field of view is given in degrees.
/// Also for more details https://www.khronos.org/registry/OpenGL-Refpages/gl2.1/xhtml/gluPerspective.xml.
/// For Reversed-Z details https://nlguillemot.wordpress.com/2016/12/07/reversed-z-in-opengl/
pub fn perspectiveReversedZ(fovy_in_degrees: T, aspect_ratio: T, z_near: T) Self {
pub fn perspectiveReversedZZeroOne(fovy_in_degrees: T, aspect_ratio: T, z_near: T) Self {
const f = 1 / @tan(root.toRadians(fovy_in_degrees) * 0.5);

return .{
Expand Down
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