From b61422541ba30169dc487bf8823adb08e40b4e61 Mon Sep 17 00:00:00 2001
From: bones_was_here <bones_was_here@xa.org.au>
Date: Tue, 12 Oct 2021 17:37:07 +1000
Subject: [PATCH] strafehud: fix and refactor jumpheight feature

The height displayed was always too small, as one or two frames
of each jump were not included (especially the first frame,
when z velocity is greatest).

It now shows the exact height predicted by the formula in physicsX.cfg
and should be correct for all physics configurations.

Also, simplified the logic and removed 6 globals.
---
 qcsrc/client/hud/panel/strafehud.qc | 63 ++++++++---------------------
 1 file changed, 17 insertions(+), 46 deletions(-)

diff --git a/qcsrc/client/hud/panel/strafehud.qc b/qcsrc/client/hud/panel/strafehud.qc
index 2f0df0821..5ddc30d23 100644
--- a/qcsrc/client/hud/panel/strafehud.qc
+++ b/qcsrc/client/hud/panel/strafehud.qc
@@ -37,12 +37,6 @@ bool state_fwd_prev = true;
 float state_fwd_time = 0;
 float starttime = 0;
 float startspeed = -1;
-float jumptime = 0;
-float jumpheight = -1;
-float jumpheight_persistent = -1;
-float jumpheight_prev = 0;
-float jumpspeed_prev = 0;
-bool  jumprestart = true;
 
 // provide basic panel cvars to old clients
 // TODO remove them after a future release (0.8.2+)
@@ -655,58 +649,35 @@ void HUD_StrafeHUD()
             startspeed = -1;
         }
 
-        // experimental: show height achieved by a single jump (doesn't work in low gravity and may not be 100% accurate)
-        if(autocvar_hud_panel_strafehud_jumpheight_fade > 0)
+        // show height achieved by a single jump
+        if(autocvar_hud_panel_strafehud_jumpheight_fade > 0 && autocvar_hud_panel_strafehud_jumpheight_size > 0)
         {
-            float text_alpha = 0;
-            float jumpheight_min = max(autocvar_hud_panel_strafehud_jumpheight_min, 0);
-            float jumpheight_current = strafeplayer.origin.z;
-            float jumpspeed_current = strafeplayer.velocity.z;
-            if(jumpspeed_prev <= jumpspeed_current || jumpheight_prev > jumpheight_current || IS_ONGROUND(strafeplayer) || swimming || IS_DEAD(strafeplayer) || spectating)
+            static float height_min = 0, height_max = 0; // ground and peak of jump z coordinates
+            static float jumpheight = 0, jumptime = 0;   // displayed value and timestamp for fade out
+
+            // tries to catch kill and spectate but those are not reliable, should just hook to kill/spectate/teleport and reset jump height there
+            if((strafeplayer.velocity.z <= 0 && height_max >= strafeplayer.origin.z) || IS_ONGROUND(strafeplayer) || swimming || IS_DEAD(strafeplayer) || spectating)
             {
-                // tries to catch kill and spectate but those are not reliable, should just hook to kill/spectate/teleport and reset jump height there
-                jumprestart = true;
+                height_min = height_max = strafeplayer.origin.z;
             }
-            else
+            else if(strafeplayer.origin.z > height_max)
             {
-                if(jumpheight < 0 || jumprestart)
-                {
-                    jumprestart = false;
-                    jumpheight = 0;
-                }
-                else
-                {
-                    jumpheight += jumpheight_current - jumpheight_prev;
-                }
-                if((jumpheight * length_conversion_factor) > jumpheight_min && jumpheight > jumpheight_persistent)
-                {
+                height_max = strafeplayer.origin.z;
+                jumpheight = (height_max - height_min) * length_conversion_factor;
+
+                if(jumpheight > max(autocvar_hud_panel_strafehud_jumpheight_min, 0))
                     jumptime = time;
-                    jumpheight_persistent = jumpheight;
-                }
-            }
-            jumpheight_prev = jumpheight_current;
-            jumpspeed_prev = jumpspeed_current;
-            if(jumpheight_persistent > 0)
-            {
-                text_alpha = cos(((time - jumptime) / autocvar_hud_panel_strafehud_jumpheight_fade) * 90 * DEG2RAD); // fade non-linear like the physics panel does
-                if((time - jumptime) > autocvar_hud_panel_strafehud_jumpheight_fade)
-                {
-                    jumpheight_persistent = -1;
-                }
             }
-            if(jumpheight_persistent > 0 && text_alpha > 0 && autocvar_hud_panel_strafehud_jumpheight_size > 0)
+
+            if((time - jumptime) <= autocvar_hud_panel_strafehud_jumpheight_fade)
             {
+                float text_alpha = cos(((time - jumptime) / autocvar_hud_panel_strafehud_jumpheight_fade) * 90 * DEG2RAD); // fade non-linear like the physics panel does
                 vector jumpheight_size = panel_size;
                 jumpheight_size.y = panel_size.y * min(autocvar_hud_panel_strafehud_jumpheight_size, 5);
                 string length_unit = GetLengthUnit(autocvar_hud_panel_strafehud_unit);
-                drawstring_aspect(panel_pos - eY * jumpheight_size.y, strcat(ftos_decimals(jumpheight_persistent * length_conversion_factor, length_decimals), autocvar_hud_panel_strafehud_unit_show ? length_unit : ""), jumpheight_size, autocvar_hud_panel_strafehud_jumpheight_color, text_alpha * panel_fg_alpha, DRAWFLAG_NORMAL);
+                drawstring_aspect(panel_pos - eY * jumpheight_size.y, strcat(ftos_decimals(jumpheight, length_decimals), autocvar_hud_panel_strafehud_unit_show ? length_unit : ""), jumpheight_size, autocvar_hud_panel_strafehud_jumpheight_color, text_alpha * panel_fg_alpha, DRAWFLAG_NORMAL);
             }
         }
-        else
-        {
-            jumpheight_prev = jumpspeed_prev = 0;
-            jumpheight = jumpheight_persistent = -1;
-        }
         draw_endBoldFont();
 
         if(speed < (maxspeed + antiflicker_speed) && !immobile)
-- 
2.39.2