[client] fonts: add freetype font rendering backend

This commit is contained in:
Quantum 2021-02-23 23:02:21 -05:00 committed by Geoffrey McRae
parent 2da81e0b5a
commit 5a075744bd
3 changed files with 306 additions and 0 deletions

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@ -19,6 +19,7 @@ function(add_font name)
endfunction() endfunction()
# Add/remove fonts here! # Add/remove fonts here!
add_font(freetype)
add_font(SDL) add_font(SDL)
list(REMOVE_AT FONTS 0) list(REMOVE_AT FONTS 0)

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@ -0,0 +1,26 @@
cmake_minimum_required(VERSION 3.0)
project(font_freetype LANGUAGES C)
find_package(PkgConfig)
pkg_check_modules(FONT_FREETYPE_PKGCONFIG REQUIRED
freetype2
fontconfig
)
add_library(font_freetype STATIC
src/freetype.c
)
target_link_libraries(font_freetype
${FONT_FREETYPE_PKGCONFIG_LIBRARIES}
lg_common
)
target_include_directories(font_freetype
PUBLIC
$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
$<INSTALL_INTERFACE:include>
PRIVATE
src
${FONT_FREETYPE_PKGCONFIG_INCLUDE_DIRS}
)

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@ -0,0 +1,279 @@
/*
Looking Glass - KVM FrameRelay (KVMFR) Client
Copyright (C) 2021 Guanzhong Chen (quantum2048@gmail.com)
https://looking-glass.io
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; either version 2 of the License, or (at your option) any later
version.
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, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdlib.h>
#include <stdbool.h>
#include "interface/font.h"
#include "common/debug.h"
#include <ft2build.h>
#include FT_FREETYPE_H
#include <fontconfig/fontconfig.h>
static int g_initCount = 0;
static FcConfig * g_fontConfig = NULL;
static FT_Library g_ft;
struct Inst
{
FT_Face face;
unsigned int height;
};
static bool lgf_freetype_create(LG_FontObj * opaque, const char * font_name, unsigned int size)
{
bool ret = false;
if (g_initCount == 0)
{
if (FT_Init_FreeType(&g_ft))
{
DEBUG_ERROR("FT_Init_FreeType Failed");
goto fail;
}
g_fontConfig = FcInitLoadConfigAndFonts();
if (!g_fontConfig)
{
DEBUG_ERROR("FcInitLoadConfigAndFonts Failed");
goto fail_init;
}
}
*opaque = malloc(sizeof(struct Inst));
if (!*opaque)
{
DEBUG_INFO("Failed to allocate %lu bytes", sizeof(struct Inst));
goto fail_config;
}
memset(*opaque, 0, sizeof(struct Inst));
struct Inst * this = (struct Inst *)*opaque;
if (!font_name)
font_name = "FreeMono";
FcPattern * pat = FcNameParse((const FcChar8*)font_name);
if (!pat)
{
DEBUG_ERROR("FCNameParse failed");
goto fail_opaque;
}
FcConfigSubstitute(g_fontConfig, pat, FcMatchPattern);
FcDefaultSubstitute(pat);
FcResult result;
FcChar8 * file = NULL;
FcPattern * match = FcFontMatch(g_fontConfig, pat, &result);
if (!match)
{
DEBUG_ERROR("FcFontMatch Failed");
goto fail_parse;
}
if (FcPatternGetString(match, FC_FILE, 0, &file) == FcResultMatch)
{
if (FT_New_Face(g_ft, (char *) file, 0, &this->face))
{
DEBUG_ERROR("FT_New_Face Failed");
goto fail_match;
}
FT_Set_Pixel_Sizes(this->face, 0, size);
this->height = size;
}
else
{
DEBUG_ERROR("Failed to locate the requested font: %s", font_name);
goto fail_match;
}
++g_initCount;
ret = true;
fail_match:
FcPatternDestroy(match);
fail_parse:
FcPatternDestroy(pat);
if (ret)
return true;
fail_opaque:
free(this);
*opaque = NULL;
fail_config:
if (g_initCount == 0)
{
FcConfigDestroy(g_fontConfig);
g_fontConfig = NULL;
}
fail_init:
if (g_initCount == 0)
FT_Done_FreeType(g_ft);
fail:
return false;
}
static void lgf_freetype_destroy(LG_FontObj opaque)
{
struct Inst * this = (struct Inst *)opaque;
if (this->face)
FT_Done_Face(this->face);
free(this);
if (--g_initCount == 0)
{
FcConfigDestroy(g_fontConfig);
g_fontConfig = NULL;
FT_Done_FreeType(g_ft);
}
}
static LG_FontBitmap * lgf_freetype_render(LG_FontObj opaque, unsigned int fg_color, const char * text)
{
struct Inst * this = (struct Inst *)opaque;
int width = 0;
int row = 0;
int rowWidth = 0;
int topAscend = 0;
int bottomDescend = 0;
for (const char * ptr = text; *ptr; ++ptr)
{
if (*ptr == '\n')
{
if (!*(ptr + 1))
break;
if (rowWidth > width)
width = rowWidth;
rowWidth = bottomDescend = 0;
++row;
}
else if (FT_Load_Char(this->face, *ptr, FT_LOAD_RENDER))
{
DEBUG_ERROR("Failed to load character: %c", *ptr);
return NULL;
}
else
{
FT_GlyphSlot glyph = this->face->glyph;
rowWidth += glyph->advance.x / 64;
int descend = glyph->bitmap.rows - glyph->bitmap_top;
if (descend > bottomDescend)
bottomDescend = descend;
if (row == 0 && glyph->bitmap_top > topAscend)
topAscend = glyph->bitmap_top;
}
}
if (rowWidth > width)
width = rowWidth;
int height = topAscend + this->height * row + bottomDescend;
uint32_t * pixels = calloc(width * height, sizeof(uint32_t));
if (!pixels)
{
DEBUG_ERROR("Failed to allocate memory for font pixels");
return NULL;
}
int baseline = topAscend;
int x = 0;
unsigned int r = (fg_color & 0xff000000) >> 24;
unsigned int g = (fg_color & 0x00ff0000) >> 16;
unsigned int b = (fg_color & 0x0000ff00) >> 8;
uint32_t color = (r << 0) | (g << 8) | (b << 16);
for (const char * ptr = text; *ptr; ++ptr)
{
if (*ptr == '\n')
{
baseline += this->height;
x = 0;
}
else if (FT_Load_Char(this->face, *ptr, FT_LOAD_RENDER))
{
DEBUG_ERROR("Failed to load character: %c", *ptr);
return NULL;
}
else
{
FT_GlyphSlot glyph = this->face->glyph;
int start = baseline - glyph->bitmap_top;
int pitch = width;
if (glyph->bitmap.pitch < 0)
{
start += glyph->bitmap.rows - 1;
pitch = -pitch;
}
for (int i = 0; i < glyph->bitmap.rows; ++i)
for (int j = 0; j < glyph->bitmap.width; ++j)
pixels[(start + i) * pitch + x + j + glyph->bitmap_left] = color |
glyph->bitmap.buffer[i * glyph->bitmap.pitch + j] << 24;
x += glyph->advance.x / 64;
}
}
LG_FontBitmap * out = malloc(sizeof(LG_FontBitmap));
if (!out)
{
free(pixels);
DEBUG_ERROR("Failed to allocate memory for font bitmap");
return NULL;
}
out->width = width;
out->height = height;
out->bpp = 4;
out->pixels = (uint8_t *) pixels;
return out;
}
static void lgf_freetype_release(LG_FontObj opaque, LG_FontBitmap * font)
{
LG_FontBitmap * bitmap = (LG_FontBitmap *)font;
free(bitmap->pixels);
free(bitmap);
}
struct LG_Font LGF_freetype =
{
.name = "freetype",
.create = lgf_freetype_create,
.destroy = lgf_freetype_destroy,
.render = lgf_freetype_render,
.release = lgf_freetype_release
};