Chams: style flags on the resident debug material

The base game only has debug/debugtranslucentsinglecolor resident, so the
other debug VMTs silently fell back to it and every style looked flat. Use that
material for every style and apply material flags instead: FLAT, WIREFRAME,
ADDITIVE, and FLAT|SELFILLUM for fullbright; white forces the colour. Flags are
cleared after the draw.

2 files changed, 43 insertions, 31 deletions

diff --git a/CONTEXT.md b/CONTEXT.md
index ce79800..72559ac 100644
--- a/CONTEXT.md
+++ b/CONTEXT.md
@@ -296,20 +296,17 @@ vocabulary / decisions.
   vars (IMaterialVar slot 11, SetVecValue 3-float slot 11), because some forced
   materials ignore ColorModulate. The shared material's flag and colour are
   restored to (false, white) after the draw.
-- Material lookup walks the `IMaterialSystem` list (`world_find_material`), with
-  `FindMaterial` (slot 71) as the fallback. The **exact requested style** is
-  tried first (resident, then loaded on demand), and only if that fails does it
-  fall back to `debug/debugtranslucentsinglecolor`/debugwhite/vgui white.
-  Styles: 0 Flat (`models/debug/debugwhite`), 1 Wireframe
-  (`debug/debugwireframe`), 2 Additive (`debug/additivevertexcolorvertexalpha`),
-  3 Solid (`debug/debugtranslucentsinglecolor`), 4 White
-  (`debug/debugtranslucentvertexcolor`), 5 Fullbright
-  (`debug/debugmrmfullbright2`). The chosen material name is logged.
+- The base game does not have the other debug VMTs resident and `FindMaterial`
+  does not make them available reliably, so all styles use the resident
+  `debug/debugtranslucentsinglecolor` and differ by material flags:
+  0 Flat (`FLAT`), 1 Wireframe (`WIREFRAME`), 2 Additive (`ADDITIVE`),
+  3 Solid (none), 4 White (colour forced to white), 5 Fullbright
+  (`FLAT|SELFILLUM`). Flags are reset after the draw.
 - `Viewmodel (hands/weapon)` applies the override to entities whose class
   contains `viewmodel` or whose model path is `.../v_...`. Viewmodels always
-  use the model-safe solid material (`debug/debugtranslucentsinglecolor`);
-  VGUI/white materials do not draw skinned models and made the hands/weapon
-  disappear. Only the normal-depth pass is used.
+  use the solid style (no style flags) with the selected colour; VGUI/white
+  materials do not draw skinned models and made the hands/weapon disappear.
+  Only the normal-depth pass is used.
 - Feature is off by default; `[chams] active/bind/walls/viewmodel/material/r/g/b`,
   with Through walls, Viewmodel, a Material dropdown and colour in the Visuals
   card.
diff --git a/src/studio.cpp b/src/studio.cpp
index f67936c..1ca8ad7 100644
--- a/src/studio.cpp
+++ b/src/studio.cpp
@@ -200,14 +200,11 @@ void *g_chams_mat = nullptr;
 int g_chams_mat_idx = -1;
 
 const char *chams_material_name(int idx) {
-  switch (idx) {
-  case 1: return "debug/debugwireframe";
-  case 2: return "debug/additivevertexcolorvertexalpha";
-  case 3: return "debug/debugtranslucentsinglecolor";
-  case 4: return "debug/debugtranslucentvertexcolor";
-  case 5: return "debug/debugmrmfullbright2";
-  default: return "models/debug/debugwhite";
-  }
+  (void)idx;
+  // Only this debug material is reliably resident in the base game; the other
+  // debug VMTs are not loaded and FindMaterial does not make them available.
+  // Visual styles are applied as material flags instead.
+  return "debug/debugtranslucentsinglecolor";
 }
 
 void *chams_material() {
@@ -248,12 +245,29 @@ void chams_color(void *mat, float r, float g, float b) {
   vfunc<ColorFn>(mat, 28)(mat, r, g, b);
 }
 
-void chams_apply(void *mat, bool ignorez) {
+void chams_apply(void *mat, bool ignorez, int style, bool force_white) {
+  using FlagFn = void (*)(void *, int, bool);
+  float r = force_white ? 1.0f : (float)g_chams_rgb[0] / 255.0f;
+  float g = force_white ? 1.0f : (float)g_chams_rgb[1] / 255.0f;
+  float b = force_white ? 1.0f : (float)g_chams_rgb[2] / 255.0f;
+  chams_color(mat, r, g, b);
+  // 0 Flat, 1 Wireframe, 2 Additive, 3 Solid, 4 White, 5 Fullbright.
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 15 /* IGNOREZ */, ignorez);
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 28 /* WIREFRAME */, style == 1);
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 7 /* ADDITIVE */, style == 2);
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 12 /* FLAT */,
+                         style == 0 || style == 5);
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 6 /* SELFILLUM */, style == 5);
+}
+
+void chams_reset(void *mat) {
   using FlagFn = void (*)(void *, int, bool);
-  chams_color(mat, (float)g_chams_rgb[0] / 255.0f,
-              (float)g_chams_rgb[1] / 255.0f,
-              (float)g_chams_rgb[2] / 255.0f);
-  vfunc<FlagFn>(mat, 29)(mat, 1 << 15 /* MATERIAL_VAR_IGNOREZ */, ignorez);
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 15, false);
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 28, false);
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 7, false);
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 12, false);
+  vfunc<FlagFn>(mat, 29)(mat, 1 << 6, false);
+  chams_color(mat, 1.0f, 1.0f, 1.0f);
 }
 
 void hkdModelExecute(void *self, const void *state, const void *info,
@@ -269,19 +283,20 @@ void hkdModelExecute(void *self, const void *state, const void *info,
       if (is_npc || is_vm) {
         void *mat = is_vm ? viewmodel_material() : chams_material();
         if (mat) {
+          int style = is_vm ? 3 : g_chams_mat_index;
+          if (style < 0) style = 0;
+          if (style > 5) style = 5;
+          bool white = !is_vm && style == 4;
           if (g_chams_walls && !is_vm) {
-            chams_apply(mat, true);
+            chams_apply(mat, true, style, white);
             g_force_override(self, mat, 0 /* OVERRIDE_NORMAL */);
             g_orig_model_exec(self, state, info, bone);
           }
-          chams_apply(mat, false);
+          chams_apply(mat, false, style, white);
           g_force_override(self, mat, 0);
           g_orig_model_exec(self, state, info, bone);
           g_force_override(self, nullptr, 0);
-          // debugwhite is shared: restore colour and depth behaviour.
-          using FlagFn = void (*)(void *, int, bool);
-          vfunc<FlagFn>(mat, 29)(mat, 1 << 15, false);
-          chams_color(mat, 1.0f, 1.0f, 1.0f);
+          chams_reset(mat);
           return;
         }
       }