X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=init.h;h=3ecc29b6270242c4fb43390c75bc15de3fd646c5;hp=7cee8587758331566d1b5b7e57db20e6f25aa2ab;hb=6f1efa8348a90a393187c12d70fd10d81bbd2c99;hpb=49ef2523611e215b327cd26f7bf698d1516edd46

diff --git a/init.h b/init.h
index 7cee858..3ecc29b 100644
--- a/init.h
+++ b/init.h
@@ -1,8 +1,11 @@
-#ifndef _INIT_H
-#define _INIT_H
+#ifndef _MOVIT_INIT_H
+#define _MOVIT_INIT_H
 
+#include "defs.h"
 #include <string>
 
+namespace movit {
+
 enum MovitDebugLevel {
 	MOVIT_DEBUG_OFF = 0,
 	MOVIT_DEBUG_ON = 1,
@@ -10,7 +13,8 @@ enum MovitDebugLevel {
 
 // Initialize the library; in particular, will query the GPU for information
 // that is needed by various components. For instance, it verifies that
-// we have all the OpenGL extensions we need.
+// we have all the OpenGL extensions we need. Returns true if initialization
+// succeeded.
 //
 // The first parameter gives which directory to read .frag files from.
 // This is a temporary hack until we add something more solid.
@@ -20,8 +24,8 @@ enum MovitDebugLevel {
 // generated shaders to the current directory.
 //
 // If you call init_movit() twice with different parameters,
-// only the first will count.
-void init_movit(const std::string& data_directory, MovitDebugLevel debug_level);
+// only the first will count, and the second will always return true.
+bool init_movit(const std::string& data_directory, MovitDebugLevel debug_level) MUST_CHECK_RESULT;
 
 // GPU features. These are not intended for end-user use.
 
@@ -44,7 +48,37 @@ extern MovitDebugLevel movit_debug_level;
 // We currently don't bother to test for more than 1024 levels.
 extern float movit_texel_subpixel_precision;
 
+// Some GPUs use very inaccurate fixed-function circuits for rounding
+// floating-point values to 8-bit outputs, leading to absurdities like
+// the roundoff point between 128 and 129 being 128.62 instead of 128.6.
+// We test, for every integer, x+0.48 and x+0.52 and check that they
+// round the right way (giving some leeway, but not a lot); the number
+// of errors are stored here.
+//
+// If this value is above 0, the extension GL_EXT_gpu_shader4 is available
+// (giving round()) and you have enabled dithering, we will round off
+// explicitly at the very end of the shader.
+//
+// Note: I don't know of any cards that round off wrong (well, outside
+// our tolerance) and do not have this extension.
+extern int movit_num_wrongly_rounded;
+extern bool movit_shader_rounding_supported;
+
 // Whether the GPU in use supports GL_EXT_texture_sRGB.
 extern bool movit_srgb_textures_supported;
 
-#endif  // !defined(_INIT_H)
+// Whether the OpenGL driver (or GPU) in use supports GL_ARB_timer_query.
+extern bool movit_timer_queries_supported;
+
+// What shader model we are compiling for. This only affects the choice
+// of a few files (like header.frag); most of the shaders are the same.
+enum MovitShaderModel {
+	MOVIT_GLSL_110,
+	MOVIT_GLSL_130,
+	MOVIT_ESSL_300
+};
+extern MovitShaderModel movit_shader_model;
+
+}  // namespace movit
+
+#endif  // !defined(_MOVIT_INIT_H)