From a56d1718de98561145aedee5a00e942ca0677429 Mon Sep 17 00:00:00 2001
From: Nathaniel MacArthur-Warner <nathanielwarner77@gmail.com>
Date: Wed, 23 Dec 2020 22:38:03 -0800
Subject: [PATCH] Check for and scale down oversize composite orthophotos

---
 simgear/scene/util/OrthophotoManager.cxx | 25 ++++++++++++++++++++++++
 simgear/scene/util/OrthophotoManager.hxx |  3 ++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/simgear/scene/util/OrthophotoManager.cxx b/simgear/scene/util/OrthophotoManager.cxx
index 9dca6ac2..4363349c 100644
--- a/simgear/scene/util/OrthophotoManager.cxx
+++ b/simgear/scene/util/OrthophotoManager.cxx
@@ -18,6 +18,7 @@
 // Boston, MA  02110-1301, USA.
 
 #include "OrthophotoManager.hxx"
+#include "SGSceneFeatures.hxx"
 #include <simgear/debug/debug_types.h>
 
 namespace simgear {
@@ -303,6 +304,30 @@ namespace simgear {
             composite_image->copySubImage(s_offset, t_offset, 0, sub_image);
         }
 
+        int max_texture_size = SGSceneFeatures::instance()->getMaxTextureSize();
+        int new_width = total_width;
+        int new_height = total_height;
+        if (new_width > max_texture_size) {
+            int factor = new_width / max_texture_size;
+            new_width /= factor;
+            new_height /= factor;
+        }
+        if (new_height > max_texture_size) {
+            int factor = new_height / max_texture_size;
+            new_width /= factor;
+            new_height /= factor;
+        }
+        if (total_width != new_width || total_height != new_height) {
+            SG_LOG(SG_OSG, SG_INFO, "Composite orthophoto exceeds the maximum texture size of your GPU. Automatic scaling will be performed.");
+            ImageRef scaled_image;
+            bool success = ImageUtils::resizeImage(composite_image, new_width, new_height, scaled_image);
+            if (success) {
+                composite_image = scaled_image;
+            } else {
+                SG_LOG(SG_OSG, SG_ALERT, "Failed to scale composite orthophoto.");
+            }
+        }
+
         _texture = textureFromImage(composite_image);
     }
 
diff --git a/simgear/scene/util/OrthophotoManager.hxx b/simgear/scene/util/OrthophotoManager.hxx
index ba2cc880..f53730f7 100644
--- a/simgear/scene/util/OrthophotoManager.hxx
+++ b/simgear/scene/util/OrthophotoManager.hxx
@@ -36,6 +36,7 @@
 #include <simgear/math/SGLimits.hxx>
 #include "SGSceneFeatures.hxx"
 #include "OsgSingleton.hxx"
+#include "SGImageUtils.hxx"
 
 namespace simgear {
 
@@ -108,4 +109,4 @@ namespace simgear {
     };
 }
 
-#endif
\ No newline at end of file
+#endif