X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=init.h;h=628915d6a68882722847d0beb0c60e7ad80b024d;hp=9c371e0316b4b6987a4a2e70ab995127d399e9d2;hb=47b4160062cdaa53b7d49d7f99ce2c686f02cff8;hpb=c8c1721179a81ac5384fab773e59be544b57128b

diff --git a/init.h b/init.h
index 9c371e0..628915d 100644
--- a/init.h
+++ b/init.h
@@ -1,16 +1,40 @@
-#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,
+};
 
 // 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.
-void init_movit();
+// 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.
+//
+// The second parameter specifies whether debugging is on or off.
+// If it is on, Movit will write intermediate graphs and the final
+// generated shaders to the current directory.
+//
+// If you call init_movit() twice with different parameters,
+// 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.
 
 // Whether init_movit() has been called.
 extern bool movit_initialized;
 
+// The current debug level.
+extern MovitDebugLevel movit_debug_level;
+
 // 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.
@@ -24,7 +48,34 @@ extern bool movit_initialized;
 // 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)
+// 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)