118 lines
2.9 KiB
Plaintext
118 lines
2.9 KiB
Plaintext
// Column-major 4x4 float matrix (OpenGL convention)
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// data[col * 4 + row]
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Mat4 :: struct {
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data: [16]f32;
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identity :: () -> Mat4 {
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Mat4.{ data = .[
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1.0, 0.0, 0.0, 0.0,
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0.0, 1.0, 0.0, 0.0,
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0.0, 0.0, 1.0, 0.0,
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0.0, 0.0, 0.0, 1.0
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]};
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}
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zero :: () -> Mat4 {
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Mat4.{ data = .[
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0.0, 0.0, 0.0, 0.0,
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0.0, 0.0, 0.0, 0.0,
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0.0, 0.0, 0.0, 0.0,
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0.0, 0.0, 0.0, 0.0
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]};
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}
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mul :: (self: Mat4, b: Mat4) -> Mat4 {
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r := Mat4.zero();
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col := 0;
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while col < 4 {
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row := 0;
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while row < 4 {
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sum : f32 = 0.0;
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k := 0;
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while k < 4 {
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sum = sum + self.data[k * 4 + row] * b.data[col * 4 + k];
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k += 1;
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}
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r.data[col * 4 + row] = sum;
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row += 1;
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}
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col += 1;
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}
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r;
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}
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translate :: (x: f32, y: f32, z: f32) -> Mat4 {
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m := Mat4.identity();
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m.data[12] = x;
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m.data[13] = y;
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m.data[14] = z;
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m;
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}
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scale :: (x: f32, y: f32, z: f32) -> Mat4 {
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m := Mat4.zero();
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m.data[0] = x;
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m.data[5] = y;
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m.data[10] = z;
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m.data[15] = 1.0;
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m;
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}
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rotate_x :: (angle: f32) -> Mat4 {
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c := cos(angle);
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s := sin(angle);
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m := Mat4.identity();
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m.data[5] = c;
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m.data[6] = s;
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m.data[9] = 0.0 - s;
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m.data[10] = c;
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m;
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}
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rotate_y :: (angle: f32) -> Mat4 {
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c := cos(angle);
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s := sin(angle);
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m := Mat4.identity();
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m.data[0] = c;
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m.data[2] = 0.0 - s;
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m.data[8] = s;
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m.data[10] = c;
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m;
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}
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rotate_z :: (angle: f32) -> Mat4 {
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c := cos(angle);
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s := sin(angle);
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m := Mat4.identity();
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m.data[0] = c;
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m.data[1] = s;
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m.data[4] = 0.0 - s;
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m.data[5] = c;
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m;
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}
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ortho :: (left: f32, right: f32, bottom: f32, top: f32, near: f32, far: f32) -> Mat4 {
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m := Mat4.zero();
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m.data[0] = 2.0 / (right - left);
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m.data[5] = 2.0 / (top - bottom);
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m.data[10] = 0.0 - 2.0 / (far - near);
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m.data[12] = 0.0 - (right + left) / (right - left);
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m.data[13] = 0.0 - (top + bottom) / (top - bottom);
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m.data[14] = 0.0 - (far + near) / (far - near);
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m.data[15] = 1.0;
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m;
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}
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perspective :: (fov: f32, aspect: f32, near: f32, far: f32) -> Mat4 {
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half_tan := sin(fov * 0.5) / cos(fov * 0.5);
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m := Mat4.zero();
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m.data[0] = 1.0 / (aspect * half_tan);
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m.data[5] = 1.0 / half_tan;
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m.data[10] = 0.0 - (far + near) / (far - near);
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m.data[11] = 0.0 - 1.0;
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m.data[14] = 0.0 - 2.0 * far * near / (far - near);
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m;
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}
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}
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