World: replace skybox changer with a PNG skybox image

sv_skyname did not take effect at runtime in this build, so the Skybox card now
replaces the skybox materials' textures with <config dir>/skybox.png.

The PNG is decoded through libpng16's simplified API (dlopen'ed, so no new link
dependency) and uploaded with IMaterialSystem::CreateTextureFromBits as an
RGBA8888 texture. IMaterialVar::SetTextureValue assigns it to $basetexture and
the HDR variants for every material in the SkyBox textures group (all six
faces get the same image).

Original textures are recorded per material/var (texture pointer plus string
fallback) and restored when the feature is off. Records survive level changes
so a reused sky material is still restorable; the override is re-applied to a
new map automatically. The card shows the image path and has a Reload image
button; a missing/unreadable PNG raises an error toast.

1 files changed, 16 insertions, 61 deletions

diff --git a/src/gui.cpp b/src/gui.cpp
index 5fb8fa7..eb53dff 100644
--- a/src/gui.cpp
+++ b/src/gui.cpp
@@ -183,11 +183,10 @@ enum CtrlKind {
   CK_SECTION,
   CK_INFO,
   CK_BUTTON,
-  CK_COLOR,
-  CK_CHOICE
+  CK_COLOR
 };
 
-enum CtrlAction { ACT_NONE = 0, ACT_RELOAD, ACT_RESET };
+enum CtrlAction { ACT_NONE = 0, ACT_RELOAD, ACT_RESET, ACT_SKY_RELOAD };
 
 struct Ctrl {
   int kind;
@@ -196,8 +195,6 @@ struct Ctrl {
   bool *bval; // CK_TOGGLE
   int *ival;  // CK_SLIDER
   int *rgb;   // CK_COLOR: three ints, 0..255
-  const char *const *opts; // CK_CHOICE: option labels
-  int nopts;
   int min, max;
   int action; // CK_BUTTON
   bool zero_unlimited; // slider: value 0 displays as "All"
@@ -256,8 +253,6 @@ static void add_ctrl(int card, int kind, const char *label, const char *desc,
   c.action = action;
   c.zero_unlimited = false;
   c.rgb = nullptr;
-  c.opts = nullptr;
-  c.nopts = 0;
   c.hue = 0.0f;
   c.sat = 0.0f;
   c.val = 1.0f;
@@ -287,19 +282,11 @@ static void add_color(int card, const char *label, const char *desc,
   add_ctrl(card, CK_COLOR, label, desc, 0, 255, nullptr, nullptr, ACT_NONE);
   g_ctrls[i].rgb = rgb;
 }
-static void add_choice(int card, const char *label, const char *desc,
-                       const char *const *opts, int nopts, int *value) {
-  int i = g_nctrl;
-  add_ctrl(card, CK_CHOICE, label, desc, 0, nopts > 0 ? nopts - 1 : 0,
-           nullptr, value, ACT_NONE);
-  g_ctrls[i].opts = opts;
-  g_ctrls[i].nopts = nopts;
-}
 
 static int ctrl_val(const Ctrl &c) {
   if (c.kind == CK_TOGGLE && c.bval)
     return *c.bval ? 1 : 0;
-  if ((c.kind == CK_SLIDER || c.kind == CK_CHOICE) && c.ival)
+  if (c.kind == CK_SLIDER && c.ival)
     return *c.ival;
   return 0;
 }
@@ -307,7 +294,7 @@ static void ctrl_set(Ctrl &c, int v) {
   if (c.kind == CK_TOGGLE && c.bval) {
     *c.bval = v != 0;
     config_save();
-  } else if ((c.kind == CK_SLIDER || c.kind == CK_CHOICE) && c.ival) {
+  } else if (c.kind == CK_SLIDER && c.ival) {
     if (v < c.min) v = c.min;
     if (v > c.max) v = c.max;
     if (*c.ival != v) {
@@ -433,12 +420,17 @@ static void build_cards() {
   add_toggle(fog, "Remove fog",
              "Disable fog entirely instead of recolouring it.", &g_fog_disable);
 
+  static char sky_label[512];
+  snprintf(sky_label, sizeof(sky_label), "Image: %s",
+           config_file_cstr("skybox.png"));
   int sky = add_card(2, &g_skybox, "Skybox",
-                     "Swap the skybox at runtime through sv_skyname. The "
-                     "map's own sky comes back on level change.",
+                     "Replace the map skybox with a PNG image from the "
+                     "config directory (all six faces).",
                      true);
-  add_choice(sky, "Sky", "Pick a skybox from the HL2 set.", skybox_options(),
-             skybox_option_count(), &g_skybox_choice);
+  add_info(sky, sky_label);
+  add_info(sky, "Edit skybox.png, then Reload image. Off restores the map sky.");
+  add_button(sky, "Reload image", "Re-read the PNG and apply it again.",
+             ACT_SKY_RELOAD);
 
   int spread = add_card(3, &g_spread, "Spread control",
                         "Choose a server shot seed that tightens the cone.",
@@ -855,8 +847,6 @@ static int header_h(const Card &c) {
 static int label_max_w(const Ctrl &c) {
   if (c.kind == CK_SLIDER)
     return S(214.0f);
-  if (c.kind == CK_CHOICE)
-    return card_content_w() - S(16.0f) - S(250.0f);
   return card_content_w() - S(16.0f) - S(110.0f);
 }
 
@@ -1431,25 +1421,6 @@ static void handle_mouse_click() {
           }
           return;
         }
-        if (ct.kind == CK_CHOICE) {
-          int base = label_row_h(ct);
-          Rect box{cr.x + cr.w - S(238.0f),
-                   by + (base - S(24.0f)) / 2, S(222.0f), S(24.0f)};
-          if (box.has(mx, my)) {
-            int v = ctrl_val(ct);
-            if (mx < box.x + S(36.0f))
-              v--;
-            else if (mx >= box.x + box.w - S(36.0f))
-              v++;
-            if (v < 0) v = 0;
-            if (ct.nopts > 0 && v >= ct.nopts) v = ct.nopts - 1;
-            if (v != ctrl_val(ct)) {
-              *ct.ival = v;
-              config_save();
-            }
-          }
-          return;
-        }
         if (ct.kind == CK_BUTTON) {
           int bw = button_w(ct.label);
           Rect b{cr.x + cr.w - S(16.0f) - bw,
@@ -1469,6 +1440,9 @@ static void handle_mouse_click() {
                 g_reset_armed = true;
                 g_reset_armed_at = now;
               }
+            } else if (ct.action == ACT_SKY_RELOAD) {
+              skybox_reload_image();
+              toastf(TOAST_INFO, "Reloading skybox.png");
             }
             return;
           }
@@ -1840,25 +1814,6 @@ static void draw_card(const Rect &clip, int index, int y) {
         outline(sw, picker_open_for(ct) ? C_ACCENT : C_BORDER, &clip);
         if (picker_open_for(ct))
           draw_picker(clip, cr, ct, by);
-      } else if (ct.kind == CK_CHOICE) {
-        int v = ctrl_val(ct);
-        const char *name = (ct.opts && v >= 0 && v < ct.nopts)
-                               ? ct.opts[v]
-                               : "?";
-        Rect box{cr.x + cr.w - S(238.0f),
-                 by + (base_h - S(24.0f)) / 2, S(222.0f), S(24.0f)};
-        fill(box, Col{45, 50, 60, 255}, &clip);
-        outline(box, C_BORDER, &clip);
-        int ty = box.y + (box.h - g_body_h) / 2;
-        text_in(clip, box.x + S(8.0f), ty, "<", g_font_body, g_body_h, 0,
-                C_DIM);
-        text_in(clip, box.x + box.w - S(16.0f), ty, ">", g_font_body, g_body_h,
-                0, C_DIM);
-        int w = text_w(name, g_body_h);
-        int tx = box.x + (box.w - w) / 2;
-        if (tx < box.x + S(24.0f))
-          tx = box.x + S(24.0f);
-        text_in(clip, tx, ty, name, g_font_body, g_body_h, 0, C_TEXT);
       }
     }
     by += rh;