Give multiplayer a compact join card in Quake 4's own style, over a softened map

AGENTS.md

@@ -49,11 +49,12 @@ This file describes project goals, rules, and upstream credits for anyone workin
 - Treat x64 as the baseline architecture for active support while staging additional modern architectures incrementally.
 - Keep credits accurate and add new attributions when incorporating upstream work.
 - Localize all user-facing UI text: never introduce hardcoded display strings in GUIs/UI code when a `#str_*` lookup is possible; add/update language-table entries whenever new text is needed.
+- Follow `docs/dev/ui-visual-design.md` for any menu, panel, or in-game GUI work: build from the shipped Quake 4 interface art, keep the 45-degree frame and button motif, and do not author new interface images.
 - Avoid adding engine-side content files (e.g., custom material scripts) unless absolutely required for compatibility; the goal is to run with the original game assets and only openQ4 binaries (engine + game modules, plus minimal external libs).
 - Any existing custom `q4base/` content is treated as an expedient bootstrap, not a long-term solution. The goal is to remove this reliance by fixing engine compatibility issues rather than shipping replacement assets.
 - For investigations, reference the log file written by `logFileName` (VS Code launch uses `logs/openq4.log`), located under `fs_savepath\<gameDir>\` (e.g. `${workspaceFolder}\\.home\\baseoq4\\logs\\openq4.log`).
 - For runtime validation, use mode-specific launch tasks: use the SP launch task for single-player testing and the MP launch task for multiplayer testing.
-- Keep `ui_autoJoin 1` enabled for multiplayer testing so clients enter gameplay automatically. Use an explicit `+set ui_autoJoin 0` only when the test specifically targets the join menu or initial spectator/join flow; do not rely on omission because the setting is archived.
+- Automated multiplayer profiles (`renderer_gameplay_benchmark.py`, `stock_asset_baseline.py`, the dedicated smokes) keep an explicit `+set ui_autoJoin 1` so clients enter gameplay without menu input. The interactive VS Code MP launch configurations instead pass `+set ui_autoJoin 0`, which is the shipped default and starts at the join screen. Always set the value explicitly; never rely on omission, because the CVar is archived.
 - Do not treat main-menu startup as sufficient validation; enter in-game/map gameplay relevant to the change before concluding tests.
 - For macOS testing/debugging, use the compliant Apple-hardware VM/host workflow in `docs/dev/macos-vm-testing-workflow.md` and `tools/macos/Invoke-openQ4MacOSWorkflow.ps1`. Keep macOS installer/restore-image inventory under `E:\ISO\macos\`. Do not use Windows VMware macOS unlocker/Hackintosh-style setup guides for openQ4 automation.
 - Use `.tmp/` directory in repository for any temporary files required for tasks.

content/baseoq4/pak0/glprogs/rvspecial_medlabs.fs

@@ -1,3 +1,21 @@
+// Composite half of the Raven special-effect blur controller
+// (SPECIAL_EFFECT_BLUR).  Its parameter contract is shared with the native
+// Vulkan pass in src/renderer/Vulkan/shaders/material_depth_aware_blur.frag,
+// so the two backends have to read the controller the same way:
+//
+//   parm 0-3  approachColor; rgb is the colour the blurred scene tints
+//             towards and a is how much of it to apply
+//   parm 4    effect range - the distance past the focus point over which the
+//             image reaches full blur, in the controller's own units
+//   parm 5    focus, normalized 0..1 against parm 7
+//   parm 6    effect strength; 0 means the controller is off, not "blur at
+//             some fixed default"
+//   parm 7    distance scale, already consumed when Depth was written
+//
+// Depth here is linear view distance normalized by parm 7, so the range is
+// converted the same way the Vulkan pass converts it (parm 4 * 0.125) and both
+// ends measure the circle of confusion against the same normalized distance.
+
 uniform sampler2D Depth;
 uniform sampler2D Blur1;
 uniform float effectRange;
@@ -11,14 +29,14 @@ void main() {
 	float depth = texture2D( Depth, uv ).r;
 	vec3 blurredScene = texture2D( Blur1, uv ).rgb;
 
-	float safeRange = max( effectRange, 0.01 );
-	float clearBand = max( 0.015, 1.0 / ( safeRange * 6.0 ) );
-	float blurFactor = smoothstep( clearBand, clearBand * ( 1.5 + safeRange * 0.5 ), abs( depth - focus ) );
-	float tintAmount = clamp( approachPercent, 0.0, 1.0 );
+	float strength = clamp( approachPercent, 0.0, 1.0 );
+	float blurRange = max( effectRange * 0.125, 0.002 );
+	float circleOfConfusion = smoothstep( 0.0, 1.0,
+		clamp( abs( depth - clamp( focus, 0.0, 1.0 ) ) / blurRange, 0.0, 1.0 ) );
+	float blurAmount = circleOfConfusion * strength;
 
-	float variance = sin( ( uv.x + uv.y + scroll ) * 6.28318531 ) * 0.5 + 0.5;
-	vec3 overlayColor = mix( blurredScene, approachColor.rgb, tintAmount * variance );
-	float alpha = blurFactor * clamp( 0.6 + tintAmount * 0.4, 0.0, 1.0 );
+	float tintAmount = blurAmount * clamp( approachColor.a, 0.0, 1.0 ) * 0.04;
+	vec3 overlayColor = mix( blurredScene, approachColor.rgb, tintAmount );
 
-	gl_FragColor = vec4( overlayColor, alpha );
+	gl_FragColor = vec4( overlayColor, blurAmount );
 }