Skybox image: fix HDR sky binding; clip checkbox/arrow drawing

The HDR sky materials use the "sky" shader with $hdrcompressedtexture (DXT5).
Assigning an RGBA8 procedural texture there sampled as compressed data and
rendered black. Point $hdrbasetexture at the image, undefine
$hdrcompressedtexture (and its 0/1/2 variants) so the shader falls back, and
call IMaterial::Refresh (37) because the sky shader binds textures in
SHADER_INIT, which is otherwise cached.

GUI: draw_checkbox and the card expand chevron ignored the content clip, so
cards scrolled out of view leaked header widgets outside the window.

Log the first regenerator call (size/pitch/first pixel) for diagnosis.

1 files changed, 35 insertions, 8 deletions

diff --git a/src/world.cpp b/src/world.cpp
index 621e5f7..aaee058 100644
--- a/src/world.cpp
+++ b/src/world.cpp
@@ -587,6 +587,13 @@ public:
       return;
     int pitch = vfunc<PitchFn>(vtf, 19)(vtf, 0);   // RowSizeInBytes(0)
     unsigned char *dst = vfunc<DataFn>(vtf, 39)(vtf, 0, 0, 0); // ImageData
+    static bool logged_regen = false;
+    if (!logged_regen) {
+      logged_regen = true;
+      logf("skybox: regenerator %dx%d pitch=%d dst=%p first=%02x%02x%02x%02x",
+           w, h, pitch, dst, g_sky_pixels[0], g_sky_pixels[1],
+           g_sky_pixels[2], g_sky_pixels[3]);
+    }
     if (!dst || pitch <= 0)
       return;
     int rows = h < g_sky_px_h ? h : g_sky_px_h;
@@ -675,24 +682,44 @@ int apply_sky_texture() {
     using SetTexFn = void (*)(void *, void *);
     auto find_var = vfunc<FindVarFn>(mat, 11); // IMaterial::FindVar
 
-    static const char *vars[] = {"$basetexture", "$hdrbasetexture",
-                                 "$hdrcompressedtexture", nullptr};
-    for (int vi = 0; vars[vi]; vi++) {
+    using GetTexFn = void *(*)(void *);
+    using IsDefFn = bool (*)(void *);
+    using UndefFn = void (*)(void *);
+    static const char *tex_vars[] = {"$basetexture", "$hdrbasetexture",
+                                     nullptr};
+    for (int vi = 0; tex_vars[vi]; vi++) {
       bool found = false;
-      void *var = find_var(mat, vars[vi], &found, false);
+      void *var = find_var(mat, tex_vars[vi], &found, false);
       if (!found || !var)
         continue;
-      using GetTexFn = void *(*)(void *);
       auto vget = vfunc<GetStrFn>(var, 6);      // GetStringValue
       auto vgettex = vfunc<GetTexFn>(var, 0);   // GetTextureValue
       auto vset = vfunc<SetTexFn>(var, 14);     // SetTextureValue
-      const char *orig = vget(var);
-      void *orig_tex = vgettex(var);
-      record_orig(name, vars[vi], orig, orig_tex);
+      record_orig(name, tex_vars[vi], vget(var), vgettex(var));
       vset(var, g_sky_tex);
       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
+    }
+    // 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;
 }