X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=util.h;h=45fe6ba922b9728c5ac827ddb4b4d63a13a8ad11;hp=627c62934d7ce857ef4bb2263e35c6d1e30d4ec9;hb=f216b7bef5a968c89f6fc78e83cc26a91e504a8a;hpb=d398770154ecc4bc95282dc45656789dd5686309

diff --git a/util.h b/util.h
index 627c629..45fe6ba 100644
--- a/util.h
+++ b/util.h
@@ -3,11 +3,12 @@
 
 // Various utilities.
 
-#include <GL/glew.h>
+#include <epoxy/gl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <Eigen/Core>
 #include <string>
+#include "defs.h"
 
 #define BUFFER_OFFSET(i) ((char *)NULL + (i))
 
@@ -24,6 +25,10 @@ void hsv2rgb_normalized(float h, float s, float v, float *r, float *g, float *b)
 // Dies if the file does not exist.
 std::string read_file(const std::string &filename);
 
+// Reads <base>.<extension>, <base>.130.<extension> or <base>.300es.<extension> and
+// returns its contents, depending on <movit_shader_level>.
+std::string read_version_dependent_file(const std::string &base, const std::string &extension);
+
 // Compile the given GLSL shader (typically a vertex or fragment shader)
 // and return the object number.
 GLuint compile_shader(const std::string &shader_src, GLenum type);
@@ -34,14 +39,44 @@ void print_3x3_matrix(const Eigen::Matrix3d &m);
 // Output a GLSL 3x3 matrix declaration.
 std::string output_glsl_mat3(const std::string &name, const Eigen::Matrix3d &m);
 
+// Output GLSL scalar, 2-length and 3-length vector declarations.
+std::string output_glsl_float(const std::string &name, float x);
+std::string output_glsl_vec2(const std::string &name, float x, float y);
+std::string output_glsl_vec3(const std::string &name, float x, float y, float z);
+
+// Calculate a / b, rounding up. Does not handle overflow correctly.
+unsigned div_round_up(unsigned a, unsigned b);
+
+enum CombineRoundingBehavior {
+	COMBINE_DO_NOT_ROUND = 0,
+	COMBINE_ROUND_TO_FP16 = 1,
+};
+
 // Calculate where to sample, and with what weight, if one wants to use
-// the GPU's bilinear hardware to sample w1 * x[0] + w2 * x[1].
+// the GPU's bilinear hardware to sample w1 * x[pos1] + w2 * x[pos2],
+// where pos1 and pos2 must be normalized coordinates describing neighboring
+// texels in the mipmap level at which you sample. <num_subtexels> is the
+// number of distinct accessible subtexels in the given mipmap level,
+// calculated by num_texels / movit_texel_subpixel_precision. It is a float
+// for performance reasons, even though it is expected to be a whole number.
+// <inv_num_subtexels> is simply its inverse (1/x).
 //
 // Note that since the GPU might have limited precision in its linear
 // interpolation, the effective weights might be different from the ones you
 // asked for. sum_sq_error, if not NULL, will contain the sum of the
 // (estimated) squared errors of the two weights.
-void combine_two_samples(float w1, float w2, float *offset, float *total_weight, float *sum_sq_error);
+//
+// The answer, in "offset", comes as a normalized coordinate,
+// so if e.g. w2 = 0, you have simply offset = pos1. If <rounding_behavior>
+// is COMBINE_ROUND_TO_FP16, the coordinate is assumed to be stored as a
+// rounded fp16 value. This enables more precise calculation of total_weight
+// and sum_sq_error.
+template<class DestFloat>
+void combine_two_samples(float w1, float w2, float pos1, float pos2, float num_subtexels, float inv_num_subtexels,
+                         DestFloat *offset, DestFloat *total_weight, float *sum_sq_error);
+
+// Create a VBO with the given data. Returns the VBO number.
+GLuint generate_vbo(GLint size, GLenum type, GLsizeiptr data_size, const GLvoid *data);
 
 // Create a VBO with the given data, and bind it to the vertex attribute
 // with name <attribute_name>. Returns the VBO number.
@@ -50,12 +85,24 @@ GLuint fill_vertex_attribute(GLuint glsl_program_num, const std::string &attribu
 // Clean up after fill_vertex_attribute().
 void cleanup_vertex_attribute(GLuint glsl_program_num, const std::string &attribute_name, GLuint vbo);
 
+// If v is not already a power of two, return the first higher power of two.
+unsigned next_power_of_two(unsigned v);
+
+// Get a pointer that represents the current OpenGL context, in a cross-platform way.
+// This is not intended for anything but identification (ie., so you can associate
+// different FBOs with different contexts); you should probably not try to cast it
+// back into anything you intend to pass into OpenGL.
+void *get_gl_context_identifier();
+
+// Used in the check_error() macro, below.
+void abort_gl_error(GLenum err, const char *filename, int line) DOES_NOT_RETURN;
+
 }  // namespace movit
 
 #ifdef NDEBUG
 #define check_error()
 #else
-#define check_error() { int err = glGetError(); if (err != GL_NO_ERROR) { printf("GL error 0x%x at %s:%d\n", err, __FILE__, __LINE__); abort(); } }
+#define check_error() { GLenum err = glGetError(); if (err != GL_NO_ERROR) { movit::abort_gl_error(err, __FILE__, __LINE__); } }
 #endif
 
 // CHECK() is like assert(), but retains any side effects no matter the compilation mode.