Changeset 10043 for ps

Timestamp:

08/20/11 19:56:12 (13 years ago)

Author:

Jan Wassenberg

Message:

feature request by philip: instead of refusing to load textures larger than the OpenGL limit, ensure they have mipmaps (unless it's s3tc, which would be too expensive to recompress) and skip levels until it fits

File:

• ps/trunk/source/lib/res/graphics/ogl_tex.cpp (modified) (6 diffs)

ps/trunk/source/lib/res/graphics/ogl_tex.cpp

@@ -78 +78 @@
 
 
-static bool filter_uses_mipmaps(GLint filter)
-{
+static bool are_mipmaps_needed(size_t width, size_t height, GLint filter)
+{
+    // can't upload the entire texture; we're going to skip some
+    // levels until it no longer exceeds the OpenGL dimension limit.
+    if((GLint)width > ogl_max_tex_size || (GLint)height > ogl_max_tex_size)
+        return true;
+
     switch(filter)
     {
@@ -467 +472 @@
         if(w == 0 || h == 0)
             WARN_RETURN(ERR::_11);
-        // .. greater than max supported tex dimension.
-        //    no-op if ogl_Init not yet called
-        if(w > (size_t)ogl_max_tex_size || h > (size_t)ogl_max_tex_size)
-            WARN_RETURN(ERR::_12);
         // .. not power-of-2.
         //    note: we can't work around this because both NV_texture_rectangle
@@ -477 +478 @@
         if(!is_pow2(w) || !is_pow2(h))
             WARN_RETURN(ERR::_13);
+
+        // no longer verify dimensions are less than ogl_max_tex_size,
+        // because we just use the higher mip levels in that case.
     }
 
@@ -755 +759 @@
     // decisions:
     // .. does filter call for uploading mipmaps?
-    const bool need_mipmaps = filter_uses_mipmaps(filter);
+    const bool need_mipmaps = are_mipmaps_needed(t->w, t->h, filter);
     // .. does the image data include mipmaps? (stored as separate
     //    images after the regular texels)
@@ -799 +803 @@
     if(*plevels_to_skip == 0)
     {
+        // if OpenGL's texture dimension limit is too small, use the
+        // higher mipmap levels. NB: the minimum guaranteed size is
+        // far too low, and menu background textures may be large.
+        GLint w = (GLint)t->w, h = (GLint)t->h;
+        while(w > ogl_max_tex_size || h > ogl_max_tex_size)
+        {
+            (*plevels_to_skip)++;
+            w /= 2; h /= 2; // doesn't matter if either dimension drops to 0
+        }
+
         // this saves texture memory by skipping some of the lower
         // (high-resolution) mip levels.
@@ -805 +819 @@
         // require uploading unused levels, which is wasteful.
         // .. can be expanded to reduce to 1/4, 1/8 by encoding factor in q_flags.
-        const size_t reduce = (q_flags & OGL_TEX_HALF_RES)? 2 : 1;
-        *plevels_to_skip = (int)ceil_log2(reduce);
+        if(q_flags & OGL_TEX_HALF_RES)
+            (*plevels_to_skip)++;
     }