From c3506b2a52ecab48287043b4488986df18396d89 Mon Sep 17 00:00:00 2001
From: BlackMATov <blackmatov@gmail.com>
Date: Tue, 16 Oct 2018 17:53:24 +0700
Subject: [PATCH] math::make_perspective_XX

---
 headers/enduro2d/math/mat4.hpp        | 77 +++++++++++++++++++++++++--
 untests/sources/untests_math/mat4.cpp |  4 +-
 2 files changed, 75 insertions(+), 6 deletions(-)

diff --git a/headers/enduro2d/math/mat4.hpp b/headers/enduro2d/math/mat4.hpp
index 4d0e8027..fca35d63 100644
--- a/headers/enduro2d/math/mat4.hpp
+++ b/headers/enduro2d/math/mat4.hpp
@@ -458,12 +458,12 @@ namespace e2d { namespace math
     }
 
     //
-    // make_orthogonal_matrix
+    // make_orthogonal_lh_matrix4
     //
 
     template < typename T >
     std::enable_if_t<std::is_floating_point<T>::value, mat4<T>>
-    make_orthogonal_matrix4(T width, T height, T znear, T zfar) {
+    make_orthogonal_lh_matrix4(T width, T height, T znear, T zfar) noexcept {
         E2D_ASSERT(!math::is_near_zero(width, T(0)));
         E2D_ASSERT(!math::is_near_zero(height, T(0)));
         E2D_ASSERT(!math::approximately(znear, zfar, T(0)));
@@ -480,8 +480,77 @@ namespace e2d { namespace math
 
     template < typename T >
     std::enable_if_t<std::is_floating_point<T>::value, mat4<T>>
-    make_orthogonal_matrix4(const vec2<T>& size, T znear, T zfar) {
-        return make_orthogonal_matrix4(size.x, size.y, znear, zfar);
+    make_orthogonal_lh_matrix4(const vec2<T>& size, T znear, T zfar) {
+        return make_orthogonal_lh_matrix4(size.x, size.y, znear, zfar);
+    }
+
+    //
+    // make_orthogonal_rh_matrix4
+    //
+
+    template < typename T >
+    std::enable_if_t<std::is_floating_point<T>::value, mat4<T>>
+    make_orthogonal_rh_matrix4(T width, T height, T znear, T zfar) noexcept {
+        E2D_ASSERT(!math::is_near_zero(width, T(0)));
+        E2D_ASSERT(!math::is_near_zero(height, T(0)));
+        E2D_ASSERT(!math::approximately(znear, zfar, T(0)));
+        const T sx = T(2) / width;
+        const T sy = T(2) / height;
+        const T sz = T(1) / (znear - zfar);
+        const T tz = znear * sz;
+        return {
+            sx,   T(0), T(0), T(0),
+            T(0), sy,   T(0), T(0),
+            T(0), T(0), sz,   T(0),
+            T(0), T(0), tz,   T(1)};
+    }
+
+    template < typename T >
+    std::enable_if_t<std::is_floating_point<T>::value, mat4<T>>
+    make_orthogonal_rh_matrix4(const vec2<T>& size, T znear, T zfar) {
+        return make_orthogonal_rh_matrix4(size.x, size.y, znear, zfar);
+    }
+
+    //
+    // make_perspective_lh_matrix4
+    //
+
+    template < typename T, typename AngleTag >
+    std::enable_if_t<std::is_floating_point<T>::value, mat4<T>>
+    make_perspective_lh_matrix4(const unit<T, AngleTag>& fov, T aspect, T znear, T zfar) noexcept {
+        E2D_ASSERT(!math::is_near_zero(aspect, T(0)));
+        E2D_ASSERT(!math::approximately(znear, zfar, T(0)));
+        E2D_ASSERT(!math::approximately(to_rad(fov), make_rad<T>(0), T(0)));
+        const T sy = T(1) / math::tan(fov * T(0.5));
+        const T sx = sy / aspect;
+        const T sz = zfar / (zfar - znear);
+        const T tz = -znear * zfar / (zfar - znear);
+        return  {
+            sx,   T(0), T(0), T(0),
+            T(0), sy,   T(0), T(0),
+            T(0), T(0), sz,   T(1),
+            T(0), T(0), tz,   T(0)};
+    }
+
+    //
+    // make_perspective_rh_matrix4
+    //
+
+    template < typename T, typename AngleTag >
+    std::enable_if_t<std::is_floating_point<T>::value, mat4<T>>
+    make_perspective_rh_matrix4(const unit<T, AngleTag>& fov, T aspect, T znear, T zfar) noexcept {
+        E2D_ASSERT(!math::is_near_zero(aspect, T(0)));
+        E2D_ASSERT(!math::approximately(znear, zfar, T(0)));
+        E2D_ASSERT(!math::approximately(to_rad(fov), make_rad<T>(0), T(0)));
+        const T sy = T(1) / math::tan(fov * T(0.5));
+        const T sx = sy / aspect;
+        const T sz = zfar / (znear - zfar);
+        const T tz = znear * zfar / (znear - zfar);
+        return  {
+            sx,   T(0), T(0), T(0),
+            T(0), sy,   T(0), T(0),
+            T(0), T(0), sz,   T(-1),
+            T(0), T(0), tz,   T(0)};
     }
 
     //
diff --git a/untests/sources/untests_math/mat4.cpp b/untests/sources/untests_math/mat4.cpp
index 09d374ac..a04eb31e 100644
--- a/untests/sources/untests_math/mat4.cpp
+++ b/untests/sources/untests_math/mat4.cpp
@@ -35,8 +35,8 @@ TEST_CASE("mat4") {
         REQUIRE(math::make_rotation_matrix4(make_rad(1.f),1.f,1.f,1.f) == math::make_rotation_matrix4(make_rad(1.f), v3f::unit()));
         REQUIRE(math::make_rotation_matrix4(make_rad(1.f),v2f(1.f,1.f),1.f) == math::make_rotation_matrix4(make_rad(1.f), v3f::unit()));
 
-        REQUIRE(math::make_orthogonal_matrix4(640.f, 480.f, 0.f, 1.f) == math::make_orthogonal_matrix4(v2f(640,480), 0.f, 1.f));
-        REQUIRE(math::make_orthogonal_matrix4(640.0, 480.0, 0.0, 1.0) == math::make_orthogonal_matrix4(v2d(640,480), 0.0, 1.0));
+        REQUIRE(math::make_orthogonal_lh_matrix4(640.f, 480.f, 0.f, 1.f) == math::make_orthogonal_lh_matrix4(v2f(640,480), 0.f, 1.f));
+        REQUIRE(math::make_orthogonal_lh_matrix4(640.0, 480.0, 0.0, 1.0) == math::make_orthogonal_lh_matrix4(v2d(640,480), 0.0, 1.0));
     }
     {
         REQUIRE(m4f(m4f::identity()) == m4f::identity());