From ae4d8ec41aa916d6edffd5b42a6dd27d4633b94e Mon Sep 17 00:00:00 2001
From: exochron <exochron@freenet.de>
Date: Mon, 16 Oct 2023 19:25:37 +0200
Subject: [PATCH] fix(ui): fix LUA error of OrbitCamera [cf#97]

---
 UI/BlizzFixes.lua | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/UI/BlizzFixes.lua b/UI/BlizzFixes.lua
index dd4bee6..7bd6729 100644
--- a/UI/BlizzFixes.lua
+++ b/UI/BlizzFixes.lua
@@ -12,6 +12,41 @@ local function fixInitialRiderBlend()
     end
 end
 
+-- Rotating the display camera wildly extends the internal vector further and further.
+-- At some point on very high/low values the UI bugs with an error. (https://legacy.curseforge.com/wow/addons/mount-journal-enhanced/issues/97)
+-- Although that might only happen with an unlocked Y-rotation/pitch.
+-- Also, when resetting the camera the whole rotation gets reverted. That looks a bit funny.
+--
+-- To fix both we keep the rotation values within a fixed boundary of -2*PI and 2*PI. That prevents the LUA error and
+-- keeps the reset rotation short.
+local function keepCameraValuesInBound()
+    local two_pi = 2 * math.pi
+    local keepValueInBound = function(self, newValue, index, interpolatedIndex)
+        if newValue < -two_pi then
+            self[index] = newValue + two_pi
+            if nil ~= self[interpolatedIndex] then
+                self[interpolatedIndex] = self[interpolatedIndex] + two_pi
+            end
+        elseif newValue > two_pi then
+            self[index] = newValue - two_pi
+            if nil ~= self[interpolatedIndex] then
+                self[interpolatedIndex] = self[interpolatedIndex] - two_pi
+            end
+        end
+    end
+
+    -- horizontal rotation
+    hooksecurefunc(MountJournal.MountDisplay.ModelScene.activeCamera, "SetYaw", function(self, yaw)
+        keepValueInBound(self, yaw, "yaw", "interpolatedYaw")
+    end)
+    -- vertical rotation
+    hooksecurefunc(MountJournal.MountDisplay.ModelScene.activeCamera, "SetPitch", function(self, pitch)
+        keepValueInBound(self, pitch, "pitch", "interpolatedPitch")
+    end)
+    -- same could be done with roll. but that's not necessary for the mount display.
+end
+
 ADDON.Events:RegisterCallback("loadUI", function()
     fixInitialRiderBlend()
+    keepCameraValuesInBound()
 end, "blizz plz fix")
\ No newline at end of file