#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.
+// 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.
// 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.
// 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;
+// 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)