X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=init.h;h=e2b7f6636989b8afe38bd2751144c38c4f02c9c7;hp=e0dbe63688fff77225e45e4a162b2ad7cf1003df;hb=5614a34b00bbcfdb3d0f5a7dc1fc4205e7088cdf;hpb=34f5f331bd3b643949ccbb0c3488af2823634d59

diff --git a/init.h b/init.h
index e0dbe63..e2b7f66 100644
--- a/init.h
+++ b/init.h
@@ -1,21 +1,37 @@
 #ifndef _INIT_H
 #define _INIT_H
 
+#include <string>
+
 // Initialize the library; in particular, will query the GPU for information
-// that is needed by various components. (In time, for instance, we will query
-// about extensions here.)
-void init_movit();
+// that is needed by various components. For instance, it verifies that
+// we have all the OpenGL extensions we need.
+//
+// The parameter gives which directory to read .frag files from.
+// This is a temporary hack until we add something more solid.
+// If you call init_movit() twice with different values for data_directory,
+// only the first will count.
+void init_movit(const std::string& data_directory);
 
 // GPU features. These are not intended for end-user use.
 
 // Whether init_movit() has been called.
 extern bool movit_initialized;
 
-// An estimate on the number of different levels the linear texture interpolation
-// of the GPU can deliver. My Intel card seems to be limited to 2^6 levels here,
-// while a modern nVidia card (GTX 550 Ti) seem to use 2^8.
+// An estimate on the smallest values the linear texture interpolation
+// of the GPU can distinguish between, i.e., for a GPU with N-bit
+// texture subpixel precision, this value will be 2^-N.
 //
-// We currently don't bother to test above 2^10.
+// From reading the little specs that exist and through practical tests,
+// the broad picture seems to be that Intel cards have 6-bit precision,
+// nVidia cards have 8-bit, and Radeon cards have 6-bit before R6xx
+// (at least when not using trilinear sampling), but can reach
+// 8-bit precision on R6xx or newer in some (unspecified) cases.
+//
+// We currently don't bother to test for more than 1024 levels.
 extern float movit_texel_subpixel_precision;
 
+// Whether the GPU in use supports GL_EXT_texture_sRGB.
+extern bool movit_srgb_textures_supported;
+
 #endif  // !defined(_INIT_H)