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Merged
AndreRenaud merged 2 commits into from
Apr 20, 2026
Merged

Adjust ttf API to expose names #172

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Adjust ttf API to expose names
AndreRenaud Apr 20, 2026
80c1f7d
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AndreRenaud Apr 20, 2026
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109 changes: 60 additions & 49 deletions pdfgen.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1158,18 +1158,21 @@ int pdf_set_font(struct pdf_doc *pdf, const char *font)
return 0;
}

int pdf_set_font_ttf(struct pdf_doc *pdf, const char *path)
const char *pdf_set_font_ttf(struct pdf_doc *pdf, const char *path)
{
FILE *fp = fopen(path, "rb");
if (!fp)
return pdf_set_err(pdf, -errno, "Unable to open font file '%s': %s",
path, strerror(errno));
int err = pdf_set_font_ttf_file(pdf, fp, path);
if (!fp) {
pdf_set_err(pdf, -errno, "Unable to open font file '%s': %s", path,
strerror(errno));
return NULL;
}
const char *res = pdf_set_font_ttf_file(pdf, fp, path);
fclose(fp);
return err;
return res;
}

int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
const char *pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp,
const char *path)
{
uint8_t *font_data;
size_t font_data_len;
Expand All @@ -1191,34 +1194,39 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
struct stat st;

if (fstat(fileno(fp), &st) < 0) {
return pdf_set_err(pdf, -errno, "Unable to stat font file '%s': %s",
path, strerror(errno));
pdf_set_err(pdf, -errno, "Unable to stat font file '%s': %s", path,
strerror(errno));
return NULL;
}
font_data_len = (size_t)st.st_size;
font_data = (uint8_t *)malloc(font_data_len);
if (!font_data) {
return pdf_set_err(pdf, -ENOMEM,
"Unable to allocate %zu bytes for font '%s'",
font_data_len, path);
pdf_set_err(pdf, -ENOMEM,
"Unable to allocate %zu bytes for font '%s'",
font_data_len, path);
return NULL;
}
if (fread(font_data, 1, font_data_len, fp) != font_data_len) {
free(font_data);
return pdf_set_err(pdf, -EIO, "Unable to read font file '%s'", path);
pdf_set_err(pdf, -EIO, "Unable to read font file '%s'", path);
return NULL;
}

if (font_data_len < 12) {
free(font_data);
return pdf_set_err(
pdf, -EINVAL, "Font file '%s' is too small to be a TrueType font",
path);
pdf_set_err(pdf, -EINVAL,
"Font file '%s' is too small to be a TrueType font",
path);
return NULL;
}
sfVersion = ttf_be32(font_data);
// TrueType fonts have sfVersion 0x00010000 or 'true' (0x74727565)
if (sfVersion != 0x00010000u && sfVersion != 0x74727565u) {
free(font_data);
return pdf_set_err(
pdf, -EINVAL, "File '%s' is not a TrueType font (version 0x%08x)",
path, sfVersion);
pdf_set_err(pdf, -EINVAL,
"File '%s' is not a TrueType font (version 0x%08x)", path,
sfVersion);
return NULL;
}

head = ttf_find_table(font_data, font_data_len, "head", &head_len);
Expand All @@ -1231,9 +1239,9 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)

if (!head || head_len < 54 || !hhea || hhea_len < 36 || !hmtx || !cmap) {
free(font_data);
return pdf_set_err(pdf, -EINVAL,
"Font '%s' is missing required TrueType tables",
path);
pdf_set_err(pdf, -EINVAL,
"Font '%s' is missing required TrueType tables", path);
return NULL;
}

// Parse head table
Expand All @@ -1245,8 +1253,8 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
macStyle = ttf_be16(head + 44);
if (units_per_em == 0) {
free(font_data);
return pdf_set_err(pdf, -EINVAL, "Font '%s' has zero units_per_em",
path);
pdf_set_err(pdf, -EINVAL, "Font '%s' has zero units_per_em", path);
return NULL;
}

// Parse hhea table
Expand Down Expand Up @@ -1318,7 +1326,7 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
if (obj->font.is_ttf && strcmp(obj->font.name, font_name) == 0) {
free(font_data);
pdf->current_font = obj;
return 0;
return obj->font.name;
}
last_font_index = obj->font.index;
}
Expand All @@ -1331,40 +1339,42 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
if (!cmap_subtable || cmap_subtable_len == 0 ||
cmap_subtable_len > font_data_len) {
free(font_data);
return pdf_set_err(pdf, -EINVAL,
"Font '%s' has no usable cmap subtable", path);
pdf_set_err(pdf, -EINVAL, "Font '%s' has no usable cmap subtable",
path);
return NULL;
}
uint8_t *cmap_copy = (uint8_t *)malloc(cmap_subtable_len);
if (!cmap_copy) {
free(font_data);
return pdf_set_err(pdf, -ENOMEM,
"Unable to allocate cmap subtable for font '%s'",
path);
pdf_set_err(pdf, -ENOMEM,
"Unable to allocate cmap subtable for font '%s'", path);
return NULL;
}
// ensure subtable fits in cmap bounds safely before blind copy
if (cmap_subtable_len > (cmap + cmap_len) - cmap_subtable) {
free(cmap_copy);
free(font_data);
return pdf_set_err(pdf, -EINVAL,
"Font '%s' cmap subtable length invalid", path);
pdf_set_err(pdf, -EINVAL, "Font '%s' cmap subtable length invalid",
path);
return NULL;
}
memcpy(cmap_copy, cmap_subtable, cmap_subtable_len);

if (hmtx_len == 0 || hmtx_len > font_data_len) {
free(cmap_copy);
free(font_data);
return pdf_set_err(pdf, -EINVAL, "Font '%s' has invalid hmtx_len",
path);
pdf_set_err(pdf, -EINVAL, "Font '%s' has invalid hmtx_len", path);
return NULL;
}

// Make a copy of the hmtx table for runtime advance-width lookups
uint8_t *hmtx_copy = (uint8_t *)malloc(hmtx_len);
if (!hmtx_copy) {
free(cmap_copy);
free(font_data);
return pdf_set_err(pdf, -ENOMEM,
"Unable to allocate hmtx table for font '%s'",
path);
pdf_set_err(pdf, -ENOMEM,
"Unable to allocate hmtx table for font '%s'", path);
return NULL;
}
memcpy(hmtx_copy, hmtx, hmtx_len);

Expand All @@ -1376,18 +1386,19 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
free(hmtx_copy);
free(cmap_copy);
free(font_data);
return pdf_set_err(pdf, -EINVAL,
"Font '%s' has invalid numberOfHMetrics", path);
pdf_set_err(pdf, -EINVAL, "Font '%s' has invalid numberOfHMetrics",
path);
return NULL;
}
uint16_t *glyph_widths =
(uint16_t *)calloc(numberOfHMetrics, sizeof(uint16_t));
if (!glyph_widths) {
free(hmtx_copy);
free(cmap_copy);
free(font_data);
return pdf_set_err(pdf, -ENOMEM,
"Unable to allocate glyph widths for font '%s'",
path);
pdf_set_err(pdf, -ENOMEM,
"Unable to allocate glyph widths for font '%s'", path);
return NULL;
}
for (uint16_t g = 0; g < numberOfHMetrics; g++) {
uint16_t advance =
Expand All @@ -1406,7 +1417,7 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
free(hmtx_copy);
free(cmap_copy);
free(font_data);
return pdf->errval;
return NULL;
}
dstr_printf(&stream_obj->stream.stream,
"<<\r\n"
Expand All @@ -1420,8 +1431,8 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
free(hmtx_copy);
free(cmap_copy);
free(font_data);
return pdf_set_err(pdf, -ENOMEM,
"Unable to allocate font stream data");
pdf_set_err(pdf, -ENOMEM, "Unable to allocate font stream data");
return NULL;
}
dstr_append(&stream_obj->stream.stream, "\r\nendstream\r\n");
free(font_data);
Expand All @@ -1432,7 +1443,7 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
free(glyph_widths);
free(hmtx_copy);
free(cmap_copy);
return pdf->errval;
return NULL;
}
strncpy(descriptor_obj->font_descriptor.font_name, font_name,
sizeof(descriptor_obj->font_descriptor.font_name) - 1);
Expand Down Expand Up @@ -1461,7 +1472,7 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
free(glyph_widths);
free(hmtx_copy);
free(cmap_copy);
return pdf->errval;
return NULL;
}
strncpy(cid_obj->cid_font.font_name, font_name,
sizeof(cid_obj->cid_font.font_name) - 1);
Expand All @@ -1477,7 +1488,7 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
if (!font_obj) {
free(hmtx_copy);
free(cmap_copy);
return pdf->errval;
return NULL;
}
strncpy(font_obj->font.name, font_name, sizeof(font_obj->font.name) - 1);
font_obj->font.name[sizeof(font_obj->font.name) - 1] = '\0';
Expand All @@ -1493,7 +1504,7 @@ int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path)
font_obj->font.cid_font_index = cid_obj->index;

pdf->current_font = font_obj;
return 0;
return font_obj->font.name;
}

struct pdf_object *pdf_append_page(struct pdf_doc *pdf)
Expand Down
10 changes: 6 additions & 4 deletions pdfgen.h
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Original file line number Diff line number Diff line change
Expand Up @@ -338,9 +338,10 @@ int pdf_set_font(struct pdf_doc *pdf, const char *font);
* and will remain until pdf_set_font or pdf_set_font_ttf is called again.
* @param pdf PDF document to update font on
* @param path Filesystem path to a TrueType (.ttf) font file
* @return < 0 on failure, 0 on success
* @return NULL on failure, name of the font to use on success (this is used
* for pdf_get_font_text_width)
*/
int pdf_set_font_ttf(struct pdf_doc *pdf, const char *path);
const char *pdf_set_font_ttf(struct pdf_doc *pdf, const char *path);

/**
* Sets the font to use for text objects by loading a TrueType font file from
Expand All @@ -349,9 +350,10 @@ int pdf_set_font_ttf(struct pdf_doc *pdf, const char *path);
* @param pdf PDF document to update font on
* @param fp TTF font file pointer (must be readable and seekable)
* @param path Name of font for error messages and for internal PDF reference
* @return < 0 on failure, 0 on success
* @return NULL on failure, name of the font to use on success
*/
int pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp, const char *path);
const char *pdf_set_font_ttf_file(struct pdf_doc *pdf, FILE *fp,
const char *path);

/**
* Calculate the width of a given string in the current font
Expand Down
4 changes: 2 additions & 2 deletions tests/main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -288,7 +288,7 @@ int main(int argc, char *argv[])
const char *ttf_path = "data/Ithaca.ttf";
pdf_append_page(pdf);
pdf_add_bookmark(pdf, NULL, -1, "TrueType Font (Unicode)");
if (pdf_set_font_ttf(pdf, ttf_path) < 0) {
if (pdf_set_font_ttf(pdf, ttf_path) == NULL) {
fprintf(stderr, "Failed to load TTF font: %s\n",
pdf_get_err(pdf, &err));
pdf_destroy(pdf);
Expand Down Expand Up @@ -346,7 +346,7 @@ int main(int argc, char *argv[])
12, 50, 600, 0, PDF_BLACK, 300, PDF_ALIGN_LEFT, NULL);

// Reload the same font (should reuse the existing object)
if (pdf_set_font_ttf(pdf, ttf_path) < 0) {
if (pdf_set_font_ttf(pdf, ttf_path) == NULL) {
fprintf(stderr, "Failed to reload TTF font\n");
pdf_destroy(pdf);
return -1;
Expand Down
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