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|
#include "font.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
/* Clips at buffer bounds */
void render_glyph(glyph_t *g, color_t *buf, unsigned int bufwidth, int offx, unsigned int offy, color_t fg, color_t bg){
unsigned int bitmap_row_width = g->width/8;
uint8_t *bitmap = ((uint8_t *)g) + sizeof(glyph_t);
for(unsigned int y=0; y < g->height; y++){
long int data = 0;
for(unsigned int i=0; i<bitmap_row_width; i++){
data <<= 8;
data |= bitmap[y*bitmap_row_width+i];
}
color_t *p = buf + (offy+y)*bufwidth + offx;
/* Take care to only render what's within the framebuffer's bounds */
for(int x=0; (x < g->width) && (offx+x < (int)bufwidth); x++){
if(offx + x >= 0){
color_t c = (data&(1<<(g->width-1))) ? fg : bg;
*p = c;
}
p++;
data <<= 1;
}
}
}
glyphtable_t *read_bdf_file(char *filename){
FILE *fontfile = fopen("unifont.bdf", "r");
if(!fontfile){
fprintf(stderr, "Error opening font file: %s\n", strerror(errno));
goto error;
}
glyphtable_t *glyph_table = read_bdf(fontfile);
if(!glyph_table){
fprintf(stderr, "Error reading font file.\n");
goto error;
}
fclose(fontfile);
return glyph_table;
error:
fclose(fontfile);
return NULL;
}
#define START_GLYPHTABLE_SIZE 256
#define MAX_GLYPHTABLE_INCREMENT 32768
glyphtable_t *extend_glyphtable(glyphtable_t *glyph_table){
size_t oldlen = glyph_table->size;
size_t newlen = oldlen + (oldlen<MAX_GLYPHTABLE_INCREMENT ? oldlen : MAX_GLYPHTABLE_INCREMENT);
if(oldlen == 0)
newlen = START_GLYPHTABLE_SIZE;
glyph_t **newdata = realloc(glyph_table->data, newlen*sizeof(glyph_t*));
if(!newdata){
fprintf(stderr, "Cannot allocate bdf glyph buffer\n");
goto error;
}
glyph_table->data = newdata;
// Clear newly allocated memory area
memset(glyph_table->data+oldlen, 0, (newlen-oldlen)*sizeof(glyph_t*));
glyph_table->size = newlen;
return glyph_table;
error:
free_glyphtable(glyph_table);
return NULL;
}
void free_glyphtable(glyphtable_t *glyph_table){
if(glyph_table){
for(unsigned int i=0; i<glyph_table->size; i++){
free(glyph_table->data[i]);
}
free(glyph_table->data);
}
free(glyph_table);
}
glyphtable_t *read_bdf(FILE *f){
glyphtable_t *glyph_table = malloc(sizeof(glyphtable_t));
if(!glyph_table){
fprintf(stderr, "Cannot allocate glyph table\n");
goto error;
}
memset(glyph_table, 0, sizeof(*glyph_table));
char* line = 0;
size_t len = 0;
glyph_t current_glyph = {-1, -1, -1, -1};
unsigned int dwidth = -1;
unsigned int encoding = -1;
void *glyph_data = 0;
for(;;){
size_t read = getline(&line, &len, f);
if(read == -1){
fprintf(stderr, "Could not read line from font file\n");
goto error;
}
if(read < 2) // Ignore empty lines
continue;
line[read-1] = '\0';
char *endptr;
char *args = strchr(line, ' ');
if(args){
*args = 0;
args++;
}
if(strcmp("ENDFONT", line) == 0){
break;
}else if(strcmp("ENCODING", line) == 0){
if(!args){
fprintf(stderr, "Invalid ENCODING line: %s %s\n", line, args);
goto error;
}
encoding = strtol(args, &endptr, 10);
if(args == endptr || *endptr != '\0'){
fprintf(stderr, "Invalid ENCODING line: %s %s\n", line, args);
goto error;
}
}else if(strcmp("BBX", line) == 0){
if(!args){
fprintf(stderr, "Invalid ENCODING line: %s %s\n", line, args);
goto error;
}
endptr = 0;
char *w = strtok_r(args, " ", &endptr);
char *h = strtok_r(NULL, " ", &endptr);
char *x = strtok_r(NULL, " ", &endptr);
char *y = strtok_r(NULL, " ", &endptr);
if(!w || !h || !x || !y){
fprintf(stderr, "Invalid BBX line: %s %s\n", line, args);
goto error;
}
current_glyph.width = atoi(w);
current_glyph.height = atoi(h);
current_glyph.x = atoi(x);
current_glyph.y = atoi(y);
}else if(strcmp("DWIDTH", line) == 0){
if(!args){
fprintf(stderr, "Invalid ENCODING line: %s %s\n", line, args);
goto error;
}
endptr = 0;
char *w = strtok_r(args, " ", &endptr);
char *h = strtok_r(NULL, " ", &endptr);
if(!w || !h){
fprintf(stderr, "Invalid DWIDTH line: %s %s\n", line, args);
goto error;
}
dwidth = strtol(w, &endptr, 10);
if(w == endptr || *endptr != '\0'){
fprintf(stderr, "Invalid DWIDTH line: %s %s\n", line, args);
goto error;
}
}else if(strcmp("BITMAP", line) == 0){
unsigned int row_bytes = dwidth/8;
glyph_data = malloc(sizeof(glyph_t) + row_bytes * current_glyph.height);
if(!glyph_data){
fprintf(stderr, "Cannot malloc() memory.\n");
goto error;
}
uint8_t *bitmap = (uint8_t *)glyph_data + sizeof(glyph_t);
if(current_glyph.width < 0 || dwidth < 0 || encoding < 0){
fprintf(stderr, "Invalid glyph: ");
if(current_glyph.width < 0)
fprintf(stderr, "No bounding box given.");
if(dwidth < 0)
fprintf(stderr, "No data width given.");
if(encoding < 0)
fprintf(stderr, "No codepoint given.");
fprintf(stderr, "\n");
goto error;
}
if(current_glyph.width != dwidth){
fprintf(stderr, "Invalid glyph: bounding box width != dwidth\n");
goto error;
}
unsigned int i=0;
while(1){
read = getline(&line, &len, f);
if(read == -1){
fprintf(stderr, "Could not read line from font file\n");
goto error;
}
if(read < 2) // Ignore empty lines
continue;
line[read-1] = '\0';
if(strncmp("ENDCHAR", line, read) == 0)
break;
if(i >= current_glyph.height){
fprintf(stderr, "Too many rows of bitmap data in glyph %d: %d > %d\n", encoding, i+1, current_glyph.height);
goto error;
}
//XXX This limits the maximum character width to sizeof(long)*8 (normally 64) piccells.
long int data = strtol(line, &endptr, 16);
if(line == endptr || *endptr != '\0'){
fprintf(stderr, "Invalid bitmap data in glyph %d: %s\n", encoding, line);
goto error;
}
// Right-align data
data >>= ((read-1)*4 - dwidth);
// Copy rightmost bytes of data to destination buffer
for(unsigned int j=0; j<row_bytes; j++){
bitmap[(i+1)*row_bytes-j-1] = data&0xFF;
data >>= 8;
}
i++;
}
if(encoding >= glyph_table->size){
glyph_table = extend_glyphtable(glyph_table);
if(!glyph_table){
fprintf(stderr, "Cannot extend glyph table.\n");
goto error;
}
}
memcpy(glyph_data, ¤t_glyph, sizeof(glyph_t));
glyph_table->data[encoding] = glyph_data;
// Reset things for next iteration
current_glyph.width = -1;
current_glyph.height = -1;
current_glyph.x = -1;
current_glyph.y = -1;
dwidth = -1;
encoding = -1;
}
}
return glyph_table;
error:
free(glyph_data);
free_glyphtable(glyph_table);
return NULL;
}
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