libwebsockets/contrib/mcufont/encoder/exporttools.hh
Andy Green e3dca87f23 lws_display: add display list / DLO support
This adds optional display list support to lws_display, using DLOs (Display
List Objects).  DLOs for rectangle / rounded rectangle (with circle as the
degenerate case), PNGs, JPEG and compressed, antialiased bitmapped fonts
and text primitives are provided.

Logical DLOs are instantiated on heap and listed into an lws_display_list
owner, DLOs handle attributes like position, bounding box, colour +
opacity, and local error diffusion backing buffer.

When the display list is complete, it can be rasterized a line at a time,
with scoped error diffusion resolved, such that no allocation for the
framebuffer is required at any point.  DLOs are freed as the rasterization
moves beyond their bounding box.

Adds a platform registry binding names and other metadata to lws_display
fonts / PNGs / JPEGs.  Provides registration, destruction and best match
selection apis.
2022-03-25 08:18:29 +00:00

53 lines
1.7 KiB
C++

// Utility functions for exporting to C source code files.
#pragma once
#include <string>
#include <vector>
#include <iostream>
#include <functional>
#include "datafile.hh"
namespace mcufont {
// Convert a file name to a valid C identifier
std::string filename_to_identifier(std::string name);
// Write a vector of integers as line-wrapped hex/integer data for initializing const array.
void wordwrap_vector(std::ostream &out, const std::vector<unsigned> &data,
const std::string &prefix, size_t width = 2);
// Write a vector of integers as a C constant array of given datatype.
void write_const_table(std::ostream &out, const std::vector<unsigned> &data,
const std::string &datatype, const std::string &tablename, char flg_is_data,
size_t width = 2);
// Get minimum tracking width of font
int get_min_x_advance(const DataFile &datafile);
// Get maximum tracking width of font
int get_max_x_advance(const DataFile &datafile);
// Select the character to use as a fallback.
int select_fallback_char(const DataFile &datafile);
// Structure to represent one consecutive range of characters.
struct char_range_t
{
uint16_t first_char;
uint16_t char_count;
std::vector<int> glyph_indices;
char_range_t(): first_char(0), char_count(0) {}
};
// Decide how to best divide the characters in the font into ranges.
// Limitations are:
// - Gaps longer than minimum_gap should result in separate ranges.
// - Each range can have encoded data size of at most maximum_size.
std::vector<char_range_t> compute_char_ranges(const DataFile &datafile,
std::function<size_t(size_t)> get_encoded_glyph_size,
size_t maximum_size,
size_t minimum_gap);
}