// 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.
+// 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 where to sample, and with what weight, if one wants to use
// 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>.
+// 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
// 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,
+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.
GLuint fill_vertex_attribute(GLuint glsl_program_num, const std::string &attribute_name, GLint size, GLenum type, GLsizeiptr data_size, const GLvoid *data);