From b57ec635fcb93f6ac2eef9d920da093b1f9c39a7 Mon Sep 17 00:00:00 2001
From: FunkyFr3sh <cc.red.alert.1@googlemail.com>
Date: Fri, 27 Sep 2024 18:11:07 +0200
Subject: [PATCH] fix opengl renderer on older hardware

---
 src/opengl_utils.c | 18 +++++++++++++-----
 src/render_ogl.c   |  2 ++
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/src/opengl_utils.c b/src/opengl_utils.c
index 8222f10..8062fdd 100644
--- a/src/opengl_utils.c
+++ b/src/opengl_utils.c
@@ -231,20 +231,28 @@ void oglu_init()
 
 BOOL oglu_ext_exists(char* ext, HDC hdc)
 {
+    BOOL got_num_extensions = FALSE;
+
     if (glGetIntegerv && glGetStringi)
     {
         GLint n = 0;
         glGetIntegerv(GL_NUM_EXTENSIONS, &n);
 
-        for (GLint i = 0; i < n; i++)
+        if (glGetError() == GL_NO_ERROR)
         {
-            char* glext = (char*)glGetStringi(GL_EXTENSIONS, i);
+            got_num_extensions = TRUE;
 
-            if (glext && strcmp(glext, ext) == 0)
-                return TRUE;
+            for (GLint i = 0; i < n; i++)
+            {
+                char* glext = (char*)glGetStringi(GL_EXTENSIONS, i);
+
+                if (glext && strcmp(glext, ext) == 0)
+                    return TRUE;
+            }
         }
     }
-    else
+
+    if (!got_num_extensions)
     {
         char* glext = (char*)glGetString(GL_EXTENSIONS);
 
diff --git a/src/render_ogl.c b/src/render_ogl.c
index be0793e..efde47f 100644
--- a/src/render_ogl.c
+++ b/src/render_ogl.c
@@ -111,6 +111,8 @@ DWORD WINAPI ogl_render_main(void)
     {
         GL_CHECK(oglu_init());
 
+        g_ogl.got_error = g_ogl.got_error || (err = glGetError()) != GL_NO_ERROR;
+
         BOOL got_swap_ctrl;
         GL_CHECK(got_swap_ctrl = oglu_ext_exists("WGL_EXT_swap_control", g_ogl.hdc));