Naive Pango Font Renderer

Main.cpp

#include <iostream>
#include <vector>
#include <string>
#include <stdexcept>

#include <clocale>
#include <cstring>
#include <cwchar>
#include <cmath>
#include <cstdio>

#include <cairo.h>

#define SHOW_DEBUG 0

using namespace std;

string map_ascii = " !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~€‚ƒ„…†‡ˆ‰Š‹ŒŽ‘’“”•–—˜™š›œžŸ¡¢£¤¥¦§¨©ª«¬­®¯°±²³´µ¶·¸¹º»¼½¾¿ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖ×ØÙÚÛÜÝÞßàáâãäåæçèéêëìíîïðñòóôõö÷øùúûüýþÿ";

static const int surface_width = 2048;
static const int surface_height = 2048;
static const int rows = 15;
static const int columns = 15;

static const char* font_name = "Roboto";
static const float font_size = 24;
static const float font_padding = 2;
static const float outline_size = 0;
static const float scale = 1;

int main(int argc, char* argv[]) {
	std::setlocale(LC_ALL, "");

	cairo_surface_t	*surface;
	cairo_t 		*cr;
	
	vector<float> glyph_widths;
	
	surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, surface_width * scale, surface_height * scale);
	cr = cairo_create(surface);

	cairo_select_font_face(cr,
		font_name, CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_BOLD);
	cairo_set_font_size(cr,
		font_size);
	
	cairo_font_extents_t fe;
	cairo_font_extents(cr, &fe);
	cairo_text_extents_t te;
	
	cairo_scale(cr, scale, scale);
	
	float cell_width = floor(fe.max_x_advance + outline_size);
	float cell_height = floor(fe.height + outline_size + (font_padding * 2));
	
	const char* ptr = map_ascii.data();
	const char* end = ptr + map_ascii.size();
	size_t i = 0;
	
 	std::mblen(NULL, 0); // reset the conversion state
	while ( ptr < end ) {
		int next = mblen(ptr, end - ptr);
		
		char* this_str = new char[1024];
		strcpy(this_str, ptr);
		
		char* this_char = new char[next];
		strncpy(this_char, this_str, next);
		this_char[next] = '\0';
		
		printf("i: %d, next: %d str: %s\n", i, next, this_char);
		
		if ( next == -1 ) {
			throw std::runtime_error("strlen_mb(): conversion error");
		}
		cairo_text_extents(cr, this_char, &te);
		
		float x_base = ( i % columns ) * cell_width;
		float y_base = ((i / columns ) % rows) * cell_height;
		
		float x_offset = (cell_width * 0.5) - te.x_bearing - te.width / 2;
		float y_offset = (cell_height * 0.5) - fe.descent + fe.height / 2;
		
		float x_pos = x_base + x_offset;
		float y_pos = y_base + y_offset;
		
		glyph_widths.push_back( ((te.x_advance - te.x_bearing*2) + font_padding)  * scale );
		
		if ( SHOW_DEBUG >= 1 ) {
			/* Maximum Height
			cairo_rectangle(cr, x_base, y_base + cell_height/2 - fe.height/2, cell_width, fe.height);
			cairo_set_source_rgba(cr,0,0,0,0.25);
			cairo_fill(cr);
			*/
			
			if ( SHOW_DEBUG >=2 ) {
				// Glyph Region
				cairo_rectangle(cr, x_pos + te.x_bearing - outline_size, y_pos + te.y_bearing - outline_size, te.width + outline_size * 2, te.height + outline_size * 2 );
				cairo_set_source_rgba(cr,1,1,0,1);
				cairo_fill(cr);
			
				cairo_rectangle(cr, x_pos + te.x_bearing, y_pos + te.y_bearing, te.width, te.height );
				cairo_set_source_rgba(cr,0.5,0.5,1,1);
				cairo_fill(cr);
				
				if ( SHOW_DEBUG >=3 ) {
					cairo_rectangle(cr, x_pos + te.x_bearing, y_pos + te.y_bearing, te.x_bearing, te.height);
					cairo_set_source_rgba(cr,0.8,0.25,0.8,1);
					cairo_fill(cr);
					
					cairo_rectangle(cr, x_pos , y_pos + te.y_bearing, te.x_advance, te.height);
					cairo_set_source_rgba(cr,1,1,0.75,1);
					cairo_fill(cr);
				}
			}
			
			// Right Border
			cairo_rectangle(cr, x_base + cell_width, y_base, 1, cell_height);
			cairo_set_source_rgba(cr,0,1,1,1);
			cairo_fill(cr);
		
			// Bottom Border
			cairo_rectangle(cr, x_base, y_base + cell_height, cell_width, 1);
			cairo_set_source_rgba(cr,1,0,1,1);
			cairo_fill(cr);
			
			if ( SHOW_DEBUG >=2 ) {
				// Vertical Center
				cairo_rectangle(cr, x_base, y_base + cell_height/2, cell_width, 1);
				cairo_set_source_rgba(cr,1,1,1,0.5);
				cairo_fill(cr);
			
				// Horizontal Center
				cairo_rectangle(cr, x_base + cell_width/2, y_base, 1, cell_height);
				cairo_set_source_rgba(cr,1,1,1,0.5);
				cairo_fill(cr);
			}
			
			// Descent
			cairo_rectangle(cr, x_base, y_base + fe.descent, cell_width, 1);
			cairo_set_source_rgba(cr,0,1,0,1);
			cairo_fill(cr);
			
			// Ascent
			cairo_rectangle(cr, x_base, y_base + fe.ascent, cell_width, 1);
			cairo_set_source_rgba(cr,1,0,0,1);
			cairo_fill(cr);
		}

		// Outline
		cairo_move_to(cr, x_pos, y_pos);
		cairo_set_source_rgba(cr,0,0,0,1);
		cairo_text_path(cr, this_char);
		cairo_set_line_width(cr, outline_size);
		cairo_stroke_preserve(cr);
				
		// Fill
		cairo_set_source_rgba(cr,1,1,1,1);
		cairo_fill(cr);
		
		ptr += next;
		++i;
	};	
	
	cairo_surface_t *surface_final;
	surface_final = cairo_surface_create_for_rectangle(surface, 0, 0, (cell_width * columns) * scale, (cell_height * rows) * scale);
	
		
	char filename[1024];
	*filename = '\0';
	sprintf( filename, "output %dx%d.png", columns, rows);
	
	cairo_surface_write_to_png(surface_final, filename);
	cairo_surface_finish(surface_final);
	cairo_surface_destroy(surface_final);
	
	cairo_surface_finish(surface);
	cairo_surface_destroy(surface);
	
	//
	FILE* metrics;
	
	metrics = fopen("output.ini", "w+");
	
	fprintf(metrics, "[common]\n");
	fprintf(metrics, "CapitalsOnly=%d\n", 0);
	fprintf(metrics, "RightToLeft=%d\n", 0);
	fprintf(metrics, "DefaultStrokeColor=%s\n", "#00000000");
	fprintf(metrics, "\n");
	fprintf(metrics, "LineSpacing=%d\n", (int)fe.height + (int)(font_padding) + (int)outline_size);
	fprintf(metrics, "Top=%d\n", (int)fe.descent);
	fprintf(metrics, "Baseline=%d\n", (int)fe.ascent);
	fprintf(metrics, "DrawExtraPixelsLeft=%d\n", (int)outline_size/2);
	fprintf(metrics, "DrawExtraPixelsRight=%d\n", (int)outline_size/2);
	fprintf(metrics, "\n");
	
	for ( size_t i = 0; i < rows; i++ ) {
		char this_line[columns+1];
		*this_line = '\0';
		for ( size_t j = 0; j < columns; j++ ) {
			size_t index = (i * columns) + j;
			strncat(this_line, &map_ascii[index], 1);
		}
		fprintf(metrics, "Line %2lu=%s\n", i, this_line);
	}
	
	fprintf(metrics, "\n");
	for ( size_t l = 0; l < glyph_widths.size(); l++ ) {
		fprintf(metrics, "%lu=%d\n", l, (int)glyph_widths[l]);
	}
	
	fclose(metrics);
	
	return 0;
}

Makefile

#### PROJECT SETTINGS ####
# The name of the executable to be created
BIN_NAME := font
# Compiler used
CXX ?= g++
# Extension of source files used in the project
SRC_EXT = cpp
# Path to the source directory, relative to the makefile
SRC_PATH = .
# General compiler flags
COMPILE_FLAGS = -std=c++11 -Wall -Wextra -g
# Additional release-specific flags
RCOMPILE_FLAGS = -D NDEBUG
# Additional debug-specific flags
DCOMPILE_FLAGS = -D DEBUG
# Add additional include paths
INCLUDES = -I $(SRC_PATH)/ -I/usr/include/cairo -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng12
# General linker settings
LINK_FLAGS = -lcairo
# Additional release-specific linker settings
RLINK_FLAGS = 
# Additional debug-specific linker settings
DLINK_FLAGS = 
# Destination directory, like a jail or mounted system
DESTDIR = /
# Install path (bin/ is appended automatically)
INSTALL_PREFIX = usr/local
#### END PROJECT SETTINGS ####

# Generally should not need to edit below this line

# Shell used in this makefile
# bash is used for 'echo -en'
SHELL = /bin/bash
# Clear built-in rules
.SUFFIXES:
# Programs for installation
INSTALL = install
INSTALL_PROGRAM = $(INSTALL)
INSTALL_DATA = $(INSTALL) -m 644

# Verbose option, to output compile and link commands
export V = false
export CMD_PREFIX = @
ifeq ($(V),true)
	CMD_PREFIX = 
endif

# Combine compiler and linker flags
release: export CXXFLAGS := $(CXXFLAGS) $(COMPILE_FLAGS) $(RCOMPILE_FLAGS)
release: export LDFLAGS := $(LDFLAGS) $(LINK_FLAGS) $(RLINK_FLAGS)
debug: export CXXFLAGS := $(CXXFLAGS) $(COMPILE_FLAGS) $(DCOMPILE_FLAGS)
debug: export LDFLAGS := $(LDFLAGS) $(LINK_FLAGS) $(DLINK_FLAGS)

# Build and output paths
release: export BUILD_PATH := build/release
release: export BIN_PATH := bin/release
debug: export BUILD_PATH := build/debug
debug: export BIN_PATH := bin/debug
install: export BIN_PATH := bin/release

# Find all source files in the source directory
SOURCES = $(shell find $(SRC_PATH)/ -name '*.$(SRC_EXT)')
# Set the object file names, with the source directory stripped
# from the path, and the build path prepended in its place
OBJECTS = $(SOURCES:$(SRC_PATH)/%.$(SRC_EXT)=$(BUILD_PATH)/%.o)
# Set the dependency files that will be used to add header dependencies
DEPS = $(OBJECTS:.o=.d)

# Macros for timing compilation
TIME_FILE = $(dir $@).$(notdir $@)_time
START_TIME = date '+%s' > $(TIME_FILE)
END_TIME = read st < $(TIME_FILE) ; \
	$(RM) $(TIME_FILE) ; \
	st=$$((`date '+%s'` - $$st - 86400)) ; \
	echo `date -u -d @$$st '+%H:%M:%S'` 

# Version macros
# Comment/remove this section to remove versioning
VERSION := $(shell git describe --tags --long --dirty --always | \
	sed 's/v\([0-9]*\)\.\([0-9]*\)\.\([0-9]*\)-\?.*-\([0-9]*\)-\(.*\)/\1 \2 \3 \4 \5/g')
VERSION_MAJOR := $(word 1, $(VERSION))
VERSION_MINOR := $(word 2, $(VERSION))
VERSION_PATCH := $(word 3, $(VERSION))
VERSION_REVISION := $(word 4, $(VERSION))
VERSION_HASH := $(word 5, $(VERSION))
VERSION_STRING := \
	"$(VERSION_MAJOR).$(VERSION_MINOR).$(VERSION_PATCH).$(VERSION_REVISION)"
override CXXFLAGS := $(CXXFLAGS) \
	-D VERSION_MAJOR=$(VERSION_MAJOR) \
	-D VERSION_MINOR=$(VERSION_MINOR) \
	-D VERSION_PATCH=$(VERSION_PATCH) \
	-D VERSION_REVISION=$(VERSION_REVISION) \
	-D VERSION_HASH=\"$(VERSION_HASH)\"

# Standard, non-optimized release build
.PHONY: release
release: dirs
	@echo "Beginning release build v$(VERSION_STRING)"
	@$(START_TIME)
	@$(MAKE) all --no-print-directory
	@echo -n "Total build time: "
	@$(END_TIME)

# Debug build for gdb debugging
.PHONY: debug
debug: dirs
	@echo "Beginning debug build v$(VERSION_STRING)"
	@$(START_TIME)
	@$(MAKE) all --no-print-directory
	@echo -n "Total build time: "
	@$(END_TIME)

# Create the directories used in the build
.PHONY: dirs
dirs:
	@echo "Creating directories"
	@mkdir -p $(dir $(OBJECTS))
	@mkdir -p $(BIN_PATH)

# Installs to the set path
.PHONY: install
install:
	@echo "Installing to $(DESTDIR)$(INSTALL_PREFIX)/bin"
	@$(INSTALL_PROGRAM) $(BIN_PATH)/$(BIN_NAME) $(DESTDIR)$(INSTALL_PREFIX)/bin

# Uninstalls the program
.PHONY: uninstall
uninstall:
	@echo "Removing $(DESTDIR)$(INSTALL_PREFIX)/bin/$(BIN_NAME)"
	@$(RM) $(DESTDIR)$(INSTALL_PREFIX)/bin/$(BIN_NAME)

# Removes all build files
.PHONY: clean
clean:
	@echo "Deleting $(BIN_NAME) symlink"
	@$(RM) $(BIN_NAME)
	@echo "Deleting directories"
	@$(RM) -r build
	@$(RM) -r bin

# Main rule, checks the executable and symlinks to the output
all: $(BIN_PATH)/$(BIN_NAME)
	@echo "Making symlink: $(BIN_NAME) -> $<"
	@$(RM) $(BIN_NAME)
	@ln -s $(BIN_PATH)/$(BIN_NAME) $(BIN_NAME)

# Link the executable
$(BIN_PATH)/$(BIN_NAME): $(OBJECTS)
	@echo "Linking: $@"
	@$(START_TIME)
	$(CMD_PREFIX)$(CXX) $(OBJECTS) $(LDFLAGS) -o $@
	@echo -en "\t Link time: "
	@$(END_TIME)

# Add dependency files, if they exist
-include $(DEPS)

# Source file rules
# After the first compilation they will be joined with the rules from the
# dependency files to provide header dependencies
$(BUILD_PATH)/%.o: $(SRC_PATH)/%.$(SRC_EXT)
	@echo "Compiling: $< -> $@"
	@$(START_TIME)
	$(CMD_PREFIX)$(CXX) $(CXXFLAGS) $(INCLUDES) -MP -MMD -c $< -o $@
	@echo -en "\t Compile time: "
	@$(END_TIME)