X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=util.h;h=f57af77691befa0afa80bb943f7d11a6e54aeadd;hp=5c15c9f789fceda67e764002413d053911524806;hb=d88ed3150376693000665b9016c0350d5d90e9e1;hpb=5b6ab865efa692b25590f302c111b30680fbacdd

diff --git a/util.h b/util.h
index 5c15c9f..f57af77 100644
--- a/util.h
+++ b/util.h
@@ -24,6 +24,10 @@ 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);
@@ -34,17 +38,37 @@ 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 2-length and 3-length vector declarations.
+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
+// pixels in the mipmap level at which you sample, and the total number of
+// pixels (in given mipmap level) is <size>.
 //
 // 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, unsigned size,
+                         DestFloat *offset, DestFloat *total_weight, float *sum_sq_error);
 
 // Create a VBO with the given data, and bind it to the vertex attribute
 // with name <attribute_name>. Returns the VBO number.
@@ -53,6 +77,15 @@ 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();
+
 }  // namespace movit
 
 #ifdef NDEBUG