1 files changed, 32 insertions, 27 deletions

diff --git a/src/world.cpp b/src/world.cpp
index 03b30a8..092df77 100644
--- a/src/world.cpp
+++ b/src/world.cpp
@@ -387,7 +387,7 @@ int paeth(int a, int b, int c) {
 }
 
 bool load_png_rgba(const char *path, std::vector<unsigned char> &pixels,
-                   int &out_w, int &out_h, bool hdr_compensation) {
+                   int &out_w, int &out_h) {
   FILE *f = fopen(path, "rb");
   if (!f) {
     logf("skybox: cannot open %s", path);
@@ -610,24 +610,6 @@ bool load_png_rgba(const char *path, std::vector<unsigned char> &pixels,
     }
   }
 
-  // HDR sky materials use the "sky" shader. It samples the compressed HDR
-  // texture as rgb *= alpha, multiplies by 8, then converts linear->sRGB for
-  // display. Cancel the 8x with alpha = 1/8 and feed linear values so the
-  // final conversion restores the original sRGB image.
-  if (hdr_compensation) {
-    for (size_t i = 0; i + 3 < pixels.size(); i += 4) {
-      float rgb[3];
-      for (int c = 0; c < 3; c++) {
-        float v = (float)pixels[i + (size_t)c] / 255.0f;
-        rgb[c] = (v <= 0.04045f) ? v / 12.92f
-                                 : powf((v + 0.055f) / 1.055f, 2.4f);
-        pixels[i + (size_t)c] = (unsigned char)(rgb[c] * 255.0f + 0.5f);
-      }
-      pixels[i + 3] = 32; // 1/8 * 255
-    }
-    logf("skybox: HDR sky shader, using linear colours with 1/8 alpha");
-  }
-
   out_w = (int)w;
   out_h = (int)h;
   return true;
@@ -692,6 +674,7 @@ SkyRegenerator g_sky_regenerator;
 void *g_sky_tex = nullptr;
 bool g_sky_tex_tried = false;
 bool g_sky_applied = false;
+bool g_sky_compensated = false;
 bool g_sky_reload = false;
 double g_sky_retry_at = 0.0;
 bool g_sky_fail_logged = false;
@@ -729,6 +712,8 @@ void record_orig(const char *material, const char *var, const char *value,
       {material, var, value ? value : "", texture});
 }
 
+bool sky_uses_hdr_shader();
+
 int apply_sky_texture() {
   void *ms = material_system();
   if (!ms || !g_sky_tex)
@@ -741,6 +726,29 @@ int apply_sky_texture() {
   int total = count(ms);
   if (total <= 0 || total > 200000)
     return 0;
+  // HDR sky materials use the "sky"/Sky_HDR_DX9 shader, which treats the
+  // compressed texture as rgb *= alpha, scales by 8, then converts
+  // linear->sRGB. Cancel the 8x with alpha = 1/8 and feed linear values so
+  // the final conversion restores the original sRGB image. Decide this here,
+  // where the materials are definitely loaded, and re-upload if needed.
+  bool hdr = sky_uses_hdr_shader();
+  if (hdr && !g_sky_compensated && !g_sky_pixels.empty()) {
+    for (size_t i = 0; i + 3 < g_sky_pixels.size(); i += 4) {
+      for (int c = 0; c < 3; c++) {
+        float v = (float)g_sky_pixels[i + (size_t)c] / 255.0f;
+        float lin = (v <= 0.04045f) ? v / 12.92f
+                                    : powf((v + 0.055f) / 1.055f, 2.4f);
+        g_sky_pixels[i + (size_t)c] = (unsigned char)(lin * 255.0f + 0.5f);
+      }
+      g_sky_pixels[i + 3] = 32; // 1/8
+    }
+    using SetRegenFn = void (*)(void *, void *);
+    using DownloadFn = void (*)(void *, void *, int);
+    vfunc<SetRegenFn>(g_sky_tex, 12)(g_sky_tex, &g_sky_regenerator);
+    vfunc<DownloadFn>(g_sky_tex, 13)(g_sky_tex, nullptr, 0);
+    g_sky_compensated = true;
+    logf("skybox: HDR sky shader, using linear colours with 1/8 alpha");
+  }
   unsigned short inv = invalid(ms);
   int seen = 0, hits = 0;
   for (unsigned short h = first(ms); h != inv; h = next(ms, h)) {
@@ -892,8 +900,7 @@ void load_sky_texture() {
   std::vector<unsigned char> pixels;
   int w = 0, h = 0;
   const char *path = config_file_cstr("skybox.png");
-  bool hdr = sky_uses_hdr_shader();
-  if (!load_png_rgba(path, pixels, w, h, hdr)) {
+  if (!load_png_rgba(path, pixels, w, h)) {
     if (!g_sky_fail_logged) {
       g_sky_fail_logged = true;
       toastf(TOAST_ERROR, "Skybox image missing or unreadable: %s", path);
@@ -908,12 +915,9 @@ void load_sky_texture() {
   // is called on Download() and again on device restore.
   using CreateProcFn = void *(*)(void *, const char *, const char *, int, int,
                                  int, int);
-  // 0x40 = TEXTUREFLAGS_SRGB: the LDR sky path decodes sRGB from the texture
-  // flags, the HDR path forces sRGB reads off and does its own conversion.
-  int tex_flags = 0x10C /* CLAMPS|CLAMPT|NOMIP */ | (hdr ? 0 : 0x40);
-  g_sky_tex = vfunc<CreateProcFn>(ms, 81)(ms, "hl2hake/skybox",
-                                          GROUP_SKYBOX, w, h, 0 /*RGBA8888*/,
-                                          tex_flags);
+  g_sky_tex = vfunc<CreateProcFn>(ms, 81)(
+      ms, "hl2hake/skybox", GROUP_SKYBOX, w, h, 0 /* RGBA8888 */,
+      0x10C /* CLAMPS|CLAMPT|NOMIP */);
   if (!g_sky_tex) {
     logf("skybox: CreateProceduralTexture failed for %dx%d", w, h);
     return;
@@ -922,6 +926,7 @@ void load_sky_texture() {
   using DownloadFn = void (*)(void *, void *, int);
   vfunc<SetRegenFn>(g_sky_tex, 12)(g_sky_tex, &g_sky_regenerator);
   vfunc<DownloadFn>(g_sky_tex, 13)(g_sky_tex, nullptr, 0);
+  g_sky_compensated = false;
   g_sky_fail_logged = false;
   logf("skybox: image %s (%dx%d) uploaded", path, w, h);
 }