Add mat4.projectionZO, which is appropriate for WebGPU's normalized device coordinates

Author: toji

src/mat4.js

@@ -1496,6 +1496,8 @@ export function frustum(out, left, right, bottom, top, near, far) {
 
 /**
  * Generates a perspective projection matrix with the given bounds.
+ * The near/far clip planes correspond to a normalized device coordinate Z range of [-1, 1],
+ * which matches WebGL/OpenGL's clip volume.
  * Passing null/undefined/no value for far will generate infinite projection matrix.
  *
  * @param {mat4} out mat4 frustum matrix will be written into
@@ -1505,7 +1507,7 @@ export function frustum(out, left, right, bottom, top, near, far) {
  * @param {number} far Far bound of the frustum, can be null or Infinity
  * @returns {mat4} out
  */
-export function perspective(out, fovy, aspect, near, far) {
+export function perspectiveNO(out, fovy, aspect, near, far) {
   let f = 1.0 / Math.tan(fovy / 2),
     nf;
   out[0] = f / aspect;
@@ -1533,6 +1535,53 @@ export function perspective(out, fovy, aspect, near, far) {
   return out;
 }
 
+/**
+ * Alias for {@link mat4.perspectiveNO}
+ * @function
+ */
+export const perspective = perspectiveNO;
+
+/**
+ * Generates a perspective projection matrix suitable for WebGPU with the given bounds.
+ * The near/far clip planes correspond to a normalized device coordinate Z range of [0, 1],
+ * which matches WebGPU/Vulkan/DirectX/Metal's clip volume.
+ * Passing null/undefined/no value for far will generate infinite projection matrix.
+ *
+ * @param {mat4} out mat4 frustum matrix will be written into
+ * @param {number} fovy Vertical field of view in radians
+ * @param {number} aspect Aspect ratio. typically viewport width/height
+ * @param {number} near Near bound of the frustum
+ * @param {number} far Far bound of the frustum, can be null or Infinity
+ * @returns {mat4} out
+ */
+export function perspectiveZO(out, fovy, aspect, near, far) {
+  let f = 1.0 / Math.tan(fovy / 2),
+    nf;
+  out[0] = f / aspect;
+  out[1] = 0;
+  out[2] = 0;
+  out[3] = 0;
+  out[4] = 0;
+  out[5] = f;
+  out[6] = 0;
+  out[7] = 0;
+  out[8] = 0;
+  out[9] = 0;
+  out[11] = -1;
+  out[12] = 0;
+  out[13] = 0;
+  out[15] = 0;
+  if (far != null && far !== Infinity) {
+    nf = 1 / (near - far);
+    out[10] = far * nf;
+    out[14] = far * near * nf;
+  } else {
+    out[10] = -1;
+    out[14] = -near;
+  }
+  return out;
+}
+
 /**
  * Generates a perspective projection matrix with the given field of view.
  * This is primarily useful for generating projection matrices to be used