From a0b8275e9cce1ec2f6c78e93f21d2462807c5a70 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Thu, 4 Sep 2025 06:04:01 -0700
Subject: [PATCH] Fixed the perspective matrix calculation (thanks
 @KonkolyTamas!)

Fixes https://github.com/libsdl-org/SDL/issues/13867

(cherry picked from commit ea1a769322a28190423d74b7188161f4484a1a22)
---
 test/testgles2.c             | 2 +-
 test/testgpu_spinning_cube.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/testgles2.c b/test/testgles2.c
index 1184eab7cb..5fad872a57 100644
--- a/test/testgles2.c
+++ b/test/testgles2.c
@@ -179,7 +179,7 @@ perspective_matrix(float fovy, float aspect, float znear, float zfar, float *r)
     int i;
     float f;
 
-    f = 1.0f / SDL_tanf(fovy * 0.5f);
+    f = 1.0f / SDL_tanf((fovy / 180.0f) * SDL_PI_F * 0.5f);
 
     for (i = 0; i < 16; i++) {
         r[i] = 0.0;
diff --git a/test/testgpu_spinning_cube.c b/test/testgpu_spinning_cube.c
index 0eeb034fbb..7ec4aeec00 100644
--- a/test/testgpu_spinning_cube.c
+++ b/test/testgpu_spinning_cube.c
@@ -133,7 +133,7 @@ perspective_matrix(float fovy, float aspect, float znear, float zfar, float *r)
     int i;
     float f;
 
-    f = 1.0f/SDL_tanf(fovy * 0.5f);
+    f = 1.0f/SDL_tanf((fovy / 180.0f) * SDL_PI_F  * 0.5f);
 
     for (i = 0; i < 16; i++) {
         r[i] = 0.0;