pixelflut-rgb-matrix-server/lib/bdf-font.cc
2020-12-26 13:23:47 +01:00

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// -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
// Copyright (C) 2014 Henner Zeller <h.zeller@acm.org>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation version 2.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://gnu.org/licenses/gpl-2.0.txt>
// Some old g++ installations need this macro to be defined for PRIx64.
#ifndef __STDC_FORMAT_MACROS
# define __STDC_FORMAT_MACROS
#endif
#include <inttypes.h>
#include "graphics.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
// The little question-mark box "<22>" for unknown code.
static const uint32_t kUnicodeReplacementCodepoint = 0xFFFD;
// Bitmap for one row. This limits the number of available columns.
// Make wider if running into trouble.
typedef uint64_t rowbitmap_t;
namespace rgb_matrix {
struct Font::Glyph {
int device_width, device_height;
int width, height;
int x_offset, y_offset;
rowbitmap_t bitmap[0]; // contains 'height' elements.
};
Font::Font() : font_height_(-1), base_line_(0) {}
Font::~Font() {
for (CodepointGlyphMap::iterator it = glyphs_.begin();
it != glyphs_.end(); ++it) {
free(it->second);
}
}
// TODO: that might not be working for all input files yet.
bool Font::LoadFont(const char *path) {
if (!path || !*path) return false;
FILE *f = fopen(path, "r");
if (f == NULL)
return false;
uint32_t codepoint;
char buffer[1024];
int dummy;
Glyph tmp;
Glyph *current_glyph = NULL;
int row = 0;
int bitmap_shift = 0;
while (fgets(buffer, sizeof(buffer), f)) {
if (sscanf(buffer, "FONTBOUNDINGBOX %d %d %d %d",
&dummy, &font_height_, &dummy, &base_line_) == 4) {
base_line_ += font_height_;
}
else if (sscanf(buffer, "ENCODING %ud", &codepoint) == 1) {
// parsed.
}
else if (sscanf(buffer, "DWIDTH %d %d", &tmp.device_width, &tmp.device_height
) == 2) {
// parsed.
}
else if (sscanf(buffer, "BBX %d %d %d %d", &tmp.width, &tmp.height,
&tmp.x_offset, &tmp.y_offset) == 4) {
current_glyph = (Glyph*) malloc(sizeof(Glyph)
+ tmp.height * sizeof(rowbitmap_t));
*current_glyph = tmp;
// We only get number of bytes large enough holding our width. We want
// it always left-aligned.
bitmap_shift =
8 * (sizeof(rowbitmap_t) - ((current_glyph->width + 7) / 8))
- current_glyph->x_offset;
row = -1; // let's not start yet, wait for BITMAP
}
else if (strncmp(buffer, "BITMAP", strlen("BITMAP")) == 0) {
row = 0;
}
else if (current_glyph && row >= 0 && row < current_glyph->height
&& (sscanf(buffer, "%" PRIx64, &current_glyph->bitmap[row]) == 1)) {
current_glyph->bitmap[row] <<= bitmap_shift;
row++;
}
else if (strncmp(buffer, "ENDCHAR", strlen("ENDCHAR")) == 0) {
if (current_glyph && row == current_glyph->height) {
free(glyphs_[codepoint]); // just in case there was one.
glyphs_[codepoint] = current_glyph;
current_glyph = NULL;
}
}
}
fclose(f);
return true;
}
Font *Font::CreateOutlineFont() const {
Font *r = new Font();
const int kBorder = 1;
r->font_height_ = font_height_ + 2*kBorder;
r->base_line_ = base_line_ + kBorder;
for (CodepointGlyphMap::const_iterator it = glyphs_.begin();
it != glyphs_.end(); ++it) {
const Glyph *orig = it->second;
const int height = orig->height + 2 * kBorder;
const size_t alloc_size = sizeof(Glyph) + height * sizeof(rowbitmap_t);
Glyph *const tmp_glyph = (Glyph*) calloc(1, alloc_size);
tmp_glyph->width = orig->width + 2*kBorder;
tmp_glyph->height = height;
tmp_glyph->device_width = orig->device_width + 2*kBorder;
tmp_glyph->device_height = height;
tmp_glyph->y_offset = orig->y_offset - kBorder;
// TODO: we don't really need bounding box, right ?
const rowbitmap_t fill_pattern = 0b111;
const rowbitmap_t start_mask = 0b010;
// Fill the border
for (int h = 0; h < orig->height; ++h) {
rowbitmap_t fill = fill_pattern;
rowbitmap_t orig_bitmap = orig->bitmap[h] >> kBorder;
for (rowbitmap_t m = start_mask; m; m <<= 1, fill <<= 1) {
if (orig_bitmap & m) {
tmp_glyph->bitmap[h+kBorder-1] |= fill;
tmp_glyph->bitmap[h+kBorder+0] |= fill;
tmp_glyph->bitmap[h+kBorder+1] |= fill;
}
}
}
// Remove original font again.
for (int h = 0; h < orig->height; ++h) {
rowbitmap_t orig_bitmap = orig->bitmap[h] >> kBorder;
tmp_glyph->bitmap[h+kBorder] &= ~orig_bitmap;
}
r->glyphs_[it->first] = tmp_glyph;
}
return r;
}
const Font::Glyph *Font::FindGlyph(uint32_t unicode_codepoint) const {
CodepointGlyphMap::const_iterator found = glyphs_.find(unicode_codepoint);
if (found == glyphs_.end())
return NULL;
return found->second;
}
int Font::CharacterWidth(uint32_t unicode_codepoint) const {
const Glyph *g = FindGlyph(unicode_codepoint);
return g ? g->device_width : -1;
}
int Font::DrawGlyph(Canvas *c, int x_pos, int y_pos,
const Color &color, const Color *bgcolor,
uint32_t unicode_codepoint) const {
const Glyph *g = FindGlyph(unicode_codepoint);
if (g == NULL) g = FindGlyph(kUnicodeReplacementCodepoint);
if (g == NULL) return 0;
y_pos = y_pos - g->height - g->y_offset;
for (int y = 0; y < g->height; ++y) {
const rowbitmap_t row = g->bitmap[y];
rowbitmap_t x_mask = (1LL<<63);
for (int x = 0; x < g->device_width; ++x, x_mask >>= 1) {
if (row & x_mask) {
c->SetPixel(x_pos + x, y_pos + y, color.r, color.g, color.b);
} else if (bgcolor) {
c->SetPixel(x_pos + x, y_pos + y, bgcolor->r, bgcolor->g, bgcolor->b);
}
}
}
return g->device_width;
}
int Font::DrawGlyph(Canvas *c, int x_pos, int y_pos, const Color &color,
uint32_t unicode_codepoint) const {
return DrawGlyph(c, x_pos, y_pos, color, NULL, unicode_codepoint);
}
} // namespace rgb_matrix