Add function glm_perspective_lh_zo

This commit adds the function `glm_perspective_lh_zo`, modelled on the
implementation of glm_perspective, but amended to provide a left-hand
coordinate system expected by DirectX, Metal and Vulkan (per the GLM
project's `glm/detail/setup.hpp`). It uses a clip-space of zero-to-one.

The function is tested against a longhand version of the algorithm it
seeks to implement as well as against the output of the GLM project's
`glm::perspectiveLH_ZO` function. This commit adds a new subdirectory
`test/glm_cmp` which contains a basic CMake file and `main.cpp`. An
interested user should link or copy or clone the GLM project into this
directory. The `main` function can be used to print the reference data
used so others can verify behaviour in the future, or add new literal
reference values.

include/cglm/cam.h

@@ -248,6 +248,39 @@ glm_perspective(float fovy, float aspect, float nearZ, float farZ, mat4 dest) {
   dest[3][2] = 2.0f * nearZ * farZ * fn;
 }
 
+/*!
+ * @brief set up perspective projection matrix with a left-hand coordinate
+ * system (suitable for DirectX, Metal and Vulkan) and a clip-space with
+ * depth values from zero to one.
+ *
+ * @param[in]  fovy    field of view angle
+ * @param[in]  aspect  aspect ratio ( width / height )
+ * @param[in]  nearVal near clipping plane
+ * @param[in]  farVal  far clipping planes
+ * @param[out] dest    result matrix
+ */
+CGLM_INLINE
+void
+glm_perspective_lh_zo(float fovy,
+                      float aspect,
+                      float nearVal,
+                      float farVal,
+                      mat4  dest) {
+  /* Impl follows glm::perspectiveLH_ZO in glm/ext/matrix_clip_space.inl */
+  float f, fn;
+
+  glm_mat4_zero(dest);
+
+  f  = 1.0f / tanf(fovy * 0.5f);
+  fn = 1.0f / (farVal - nearVal);
+
+  dest[0][0] = f / aspect;
+  dest[1][1] = f;
+  dest[2][2] = farVal * fn;
+  dest[2][3] = 1.0f;
+  dest[3][2] = -(farVal * nearVal * fn);
+}
+
 /*!
  * @brief extend perspective projection matrix's far distance
  *