Skybox image: drop Refresh/SetUndefined (crash after apply)

The last crash happened after "applied", in materialsystem while the renderer
walked a shader-parameter list that contained a null vtable entry. That points
at the Refresh()/SetUndefined experiment: undefining $hdrcompressedtexture
while the sky shader's static combo still expected it (and rebuilding state
mid-level) left a broken material.

Set the texture on $basetexture/$hdrbasetexture/$hdrcompressedtexture (and the
0/1/2 variants) and do neither SetUndefined nor Refresh: the visible-path
material binds its base texture dynamically, which is what made the earlier
black sky (empty 798x798 VTF) appear black at all. Log the first sky
material's shader name so we know whether this map uses the LDR (UnlitGeneric)
or HDR (sky) path.

1 files changed, 11 insertions, 22 deletions

diff --git a/src/world.cpp b/src/world.cpp
index 1228c7a..eac31d9 100644
--- a/src/world.cpp
+++ b/src/world.cpp
@@ -741,10 +741,12 @@ int apply_sky_texture() {
     auto find_var = vfunc<FindVarFn>(mat, 11); // IMaterial::FindVar
 
     using GetTexFn = void *(*)(void *);
-    using IsDefFn = bool (*)(void *);
-    using UndefFn = void (*)(void *);
+    using ShaderFn = const char *(*)(void *);
     static const char *tex_vars[] = {"$basetexture", "$hdrbasetexture",
-                                     nullptr};
+                                     "$hdrcompressedtexture",
+                                     "$hdrcompressedtexture0",
+                                     "$hdrcompressedtexture1",
+                                     "$hdrcompressedtexture2", nullptr};
     for (int vi = 0; tex_vars[vi]; vi++) {
       bool found = false;
       void *var = find_var(mat, tex_vars[vi], &found, false);
@@ -758,26 +760,13 @@ int apply_sky_texture() {
       if (vi == 0)
         hits++;
     }
-    // The HDR sky shader samples $hdrcompressedtexture (DXT5) when defined,
-    // which cannot hold our RGBA texture. Undefine it so the shader falls back
-    // to $hdrbasetexture, which now points at our image.
-    static const char *undef_vars[] = {
-        "$hdrcompressedtexture", "$hdrcompressedtexture0",
-        "$hdrcompressedtexture1", "$hdrcompressedtexture2", nullptr};
-    for (int vi = 0; undef_vars[vi]; vi++) {
-      bool found = false;
-      void *var = find_var(mat, undef_vars[vi], &found, false);
-      if (!found || !var)
-        continue;
-      if (!vfunc<IsDefFn>(var, 17)(var))
-        continue;
-      record_orig(name, undef_vars[vi], vfunc<GetStrFn>(var, 6)(var),
-                  vfunc<GetTexFn>(var, 0)(var));
-      vfunc<UndefFn>(var, 18)(var); // SetUndefined
+    static bool logged_shader = false;
+    if (!logged_shader) {
+      logged_shader = true;
+      const char *shader = vfunc<ShaderFn>(mat, 49)(mat); // GetShaderName
+      logf("skybox: first sky material \"%s\" shader \"%s\"", name,
+           shader ? shader : "?");
     }
-    // The sky shader binds its texture in SHADER_INIT, so changing the vars is
-    // not enough: rebuild the material's shader state.
-    vfunc<void (*)(void *)>(mat, 37)(mat); // IMaterial::Refresh
   }
   return hits;
 }