texture: fix get_clear_data() return type, make it work with sRGB

panda/src/glstuff/glGraphicsStateGuardian_src.cxx

@@ -12323,20 +12323,20 @@ upload_texture_image(CLP(TextureContext) *gtc, bool needs_reload,
               if (_supports_clear_texture) {
                 // We can do that with the convenient glClearTexImage
                 // function.
-                string clear_data = tex->get_clear_data();
+                vector_uchar clear_data = tex->get_clear_data();
 
                 _glClearTexImage(gtc->_index, n - mipmap_bias, external_format,
-                                 component_type, (void *)clear_data.data());
+                                 component_type, (void *)&clear_data[0]);
                 continue;
               }
             } else {
               if (_supports_clear_buffer) {
                 // For buffer textures we need to clear the underlying
                 // storage.
-                string clear_data = tex->get_clear_data();
+                vector_uchar clear_data = tex->get_clear_data();
 
                 _glClearBufferData(GL_TEXTURE_BUFFER, internal_format, external_format,
-                                   component_type, (const void *)clear_data.data());
+                                   component_type, (const void *)&clear_data[0]);
                 continue;
               }
             }

panda/src/gobj/texture.I

@@ -279,12 +279,12 @@ clear_clear_color() {
  * Returns the raw image data for a single pixel if it were set to the clear
  * color.
  */
-INLINE string Texture::
+INLINE vector_uchar Texture::
 get_clear_data() const {
   CDReader cdata(_cycler);
-  unsigned char data[16];
-  size_t size = do_get_clear_data(cdata, data);
-  return string((char *)data, size);
+  vector_uchar data(16);
+  data.resize(do_get_clear_data(cdata, &data[0]));
+  return data;
 }
 
 /**

panda/src/gobj/texture.cxx

@@ -5584,10 +5584,28 @@ do_get_clear_data(const CData *cdata, unsigned char *into) const {
   nassertr(cdata->_has_clear_color, 0);
   nassertr(cdata->_num_components <= 4, 0);
 
-  // TODO: encode the color into the sRGB color space if used
   switch (cdata->_component_type) {
   case T_unsigned_byte:
-    {
+    if (is_srgb(cdata->_format)) {
+      xel color;
+      xelval alpha;
+      encode_sRGB_uchar(cdata->_clear_color, color, alpha);
+      switch (cdata->_num_components) {
+      case 2:
+        into[1] = (unsigned char)color.g;
+      case 1:
+        into[0] = (unsigned char)color.r;
+        break;
+      case 4:
+        into[3] = (unsigned char)alpha;
+      case 3: // BGR <-> RGB
+        into[0] = (unsigned char)color.b;
+        into[1] = (unsigned char)color.g;
+        into[2] = (unsigned char)color.r;
+        break;
+      }
+      break;
+    } else {
       LColor scaled = cdata->_clear_color.fmin(LColor(1)).fmax(LColor::zero());
       scaled *= 255;
       switch (cdata->_num_components) {

panda/src/gobj/texture.h

@@ -265,7 +265,7 @@ PUBLISHED:
   INLINE LColor get_clear_color() const;
   INLINE void set_clear_color(const LColor &color);
   INLINE void clear_clear_color();
-  INLINE string get_clear_data() const;
+  INLINE vector_uchar get_clear_data() const;
   MAKE_PROPERTY2(clear_color, has_clear_color, get_clear_color,
                               set_clear_color, clear_clear_color);