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315503e9d5
Pillow/_imagingft.c
Fabio M. Costa 0b9e404761 DRYing out the code
2013-04-12 01:25:16 -04:00

570 lines
15 KiB
C
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/*
* PIL FreeType Driver
*
* a FreeType 2.X driver for PIL
*
* history:
* 2001-02-17 fl Created (based on old experimental freetype 1.0 code)
* 2001-04-18 fl Fixed some egcs compiler nits
* 2002-11-08 fl Added unicode support; more font metrics, etc
* 2003-05-20 fl Fixed compilation under 1.5.2 and newer non-unicode builds
* 2003-09-27 fl Added charmap encoding support
* 2004-05-15 fl Fixed compilation for FreeType 2.1.8
* 2004-09-10 fl Added support for monochrome bitmaps
* 2006-06-18 fl Fixed glyph bearing calculation
* 2007-12-23 fl Fixed crash in family/style attribute fetch
* 2008-01-02 fl Handle Unicode filenames properly
*
* Copyright (c) 1998-2007 by Secret Labs AB
*/
#include "Python.h"
#include "Imaging.h"
#if !defined(USE_FREETYPE_2_0)
/* undef/comment out to use freetype 2.0 */
#define USE_FREETYPE_2_1
#endif
#if defined(USE_FREETYPE_2_1)
/* freetype 2.1 and newer */
#include <ft2build.h>
#include FT_FREETYPE_H
#else
/* freetype 2.0 */
#include <freetype/freetype.h>
#endif
#include FT_GLYPH_H
#define KEEP_PY_UNICODE
#include "py3.h"
#if !defined(FT_LOAD_TARGET_MONO)
#define FT_LOAD_TARGET_MONO FT_LOAD_MONOCHROME
#endif
/* -------------------------------------------------------------------- */
/* error table */
#undef FTERRORS_H
#undef __FTERRORS_H__
#define FT_ERRORDEF( e, v, s ) { e, s },
#define FT_ERROR_START_LIST {
#define FT_ERROR_END_LIST { 0, 0 } };
struct {
int code;
const char* message;
} ft_errors[] =
#include <freetype/fterrors.h>
/* -------------------------------------------------------------------- */
/* font objects */
static FT_Library library;
typedef struct {
PyObject_HEAD
FT_Face face;
} FontObject;
static PyTypeObject Font_Type;
/* round a 26.6 pixel coordinate to the nearest larger integer */
#define PIXEL(x) ((((x)+63) & -64)>>6)
static PyObject*
geterror(int code)
{
int i;
for (i = 0; ft_errors[i].message; i++)
if (ft_errors[i].code == code) {
PyErr_SetString(PyExc_IOError, ft_errors[i].message);
return NULL;
}
PyErr_SetString(PyExc_IOError, "unknown freetype error");
return NULL;
}
static PyObject*
getfont(PyObject* self_, PyObject* args, PyObject* kw)
{
/* create a font object from a file name and a size (in pixels) */
FontObject* self;
int error;
char* filename;
int size;
int index = 0;
unsigned char* encoding = NULL;
static char* kwlist[] = {
"filename", "size", "index", "encoding", NULL
};
if (!PyArg_ParseTupleAndKeywords(args, kw, "eti|is", kwlist,
Py_FileSystemDefaultEncoding, &filename,
&size, &index, &encoding))
return NULL;
if (!library) {
PyErr_SetString(
PyExc_IOError,
"failed to initialize FreeType library"
);
return NULL;
}
self = PyObject_New(FontObject, &Font_Type);
if (!self)
return NULL;
error = FT_New_Face(library, filename, index, &self->face);
if (!error)
error = FT_Set_Pixel_Sizes(self->face, 0, size);
if (!error && encoding && strlen((char*) encoding) == 4) {
FT_Encoding encoding_tag = FT_MAKE_TAG(
encoding[0], encoding[1], encoding[2], encoding[3]
);
error = FT_Select_Charmap(self->face, encoding_tag);
}
if (error) {
PyObject_Del(self);
return geterror(error);
}
return (PyObject*) self;
}
static int
font_getchar(PyObject* string, int index, FT_ULong* char_out)
{
if (PyUnicode_Check(string)) {
Py_UNICODE* p = PyUnicode_AS_UNICODE(string);
int size = PyUnicode_GET_SIZE(string);
if (index >= size)
return 0;
*char_out = p[index];
return 1;
}
#if PY_VERSION_HEX < 0x03000000
if (PyString_Check(string)) {
unsigned char* p = (unsigned char*) PyString_AS_STRING(string);
int size = PyString_GET_SIZE(string);
if (index >= size)
return 0;
*char_out = (unsigned char) p[index];
return 1;
}
#endif
return 0;
}
static PyObject*
font_getsize(FontObject* self, PyObject* args)
{
int i, x, y_max, y_min;
FT_ULong ch;
FT_Face face;
int xoffset;
FT_Bool kerning = FT_HAS_KERNING(self->face);
FT_UInt last_index = 0;
/* calculate size and bearing for a given string */
PyObject* string;
if (!PyArg_ParseTuple(args, "O:getsize", &string))
return NULL;
#if PY_VERSION_HEX >= 0x03000000
if (!PyUnicode_Check(string)) {
#else
if (!PyUnicode_Check(string) && !PyString_Check(string)) {
#endif
PyErr_SetString(PyExc_TypeError, "expected string");
return NULL;
}
face = NULL;
xoffset = 0;
y_max = y_min = 0;
for (x = i = 0; font_getchar(string, i, &ch); i++) {
int index, error;
face = self->face;
index = FT_Get_Char_Index(face, ch);
if (kerning && last_index && index) {
FT_Vector delta;
FT_Get_Kerning(self->face, last_index, index, ft_kerning_default,
&delta);
x += delta.x;
}
error = FT_Load_Glyph(face, index, FT_LOAD_DEFAULT);
if (error)
return geterror(error);
if (i == 0)
xoffset = face->glyph->metrics.horiBearingX;
x += face->glyph->metrics.horiAdvance;
FT_BBox bbox;
FT_Glyph glyph;
FT_Get_Glyph(face->glyph, &glyph);
FT_Glyph_Get_CBox(glyph, FT_GLYPH_BBOX_SUBPIXELS, &bbox);
if (bbox.yMax > y_max)
y_max = bbox.yMax;
if (bbox.yMin < y_min)
y_min = bbox.yMin;
last_index = index;
}
if (face) {
int offset;
/* left bearing */
if (xoffset < 0)
x -= xoffset;
else
xoffset = 0;
/* right bearing */
offset = face->glyph->metrics.horiAdvance -
face->glyph->metrics.width -
face->glyph->metrics.horiBearingX;
if (offset < 0)
x -= offset;
}
return Py_BuildValue(
"(ii)(ii)",
PIXEL(x), PIXEL(y_max - y_min),
PIXEL(xoffset), 0
);
}
static PyObject*
font_getabc(FontObject* self, PyObject* args)
{
FT_ULong ch;
FT_Face face;
double a, b, c;
/* calculate ABC values for a given string */
PyObject* string;
if (!PyArg_ParseTuple(args, "O:getabc", &string))
return NULL;
#if PY_VERSION_HEX >= 0x03000000
if (!PyUnicode_Check(string)) {
#else
if (!PyUnicode_Check(string) && !PyString_Check(string)) {
#endif
PyErr_SetString(PyExc_TypeError, "expected string");
return NULL;
}
if (font_getchar(string, 0, &ch)) {
int index, error;
face = self->face;
index = FT_Get_Char_Index(face, ch);
error = FT_Load_Glyph(face, index, FT_LOAD_DEFAULT);
if (error)
return geterror(error);
a = face->glyph->metrics.horiBearingX / 64.0;
b = face->glyph->metrics.width / 64.0;
c = (face->glyph->metrics.horiAdvance -
face->glyph->metrics.horiBearingX -
face->glyph->metrics.width) / 64.0;
} else
a = b = c = 0.0;
return Py_BuildValue("ddd", a, b, c);
}
static PyObject*
font_render(FontObject* self, PyObject* args)
{
int i, x, y;
Imaging im;
int index, error, ascender;
int load_flags;
unsigned char *source;
FT_ULong ch;
FT_GlyphSlot glyph;
FT_Bool kerning = FT_HAS_KERNING(self->face);
FT_UInt last_index = 0;
/* render string into given buffer (the buffer *must* have
the right size, or this will crash) */
PyObject* string;
Py_ssize_t id;
int mask = 0;
if (!PyArg_ParseTuple(args, "On|i:render", &string, &id, &mask))
return NULL;
#if PY_VERSION_HEX >= 0x03000000
if (!PyUnicode_Check(string)) {
#else
if (!PyUnicode_Check(string) && !PyString_Check(string)) {
#endif
PyErr_SetString(PyExc_TypeError, "expected string");
return NULL;
}
im = (Imaging) id;
load_flags = FT_LOAD_RENDER;
if (mask)
load_flags |= FT_LOAD_TARGET_MONO;
int temp;
ascender = 0;
for (i = 0; font_getchar(string, i, &ch); i++) {
index = FT_Get_Char_Index(self->face, ch);
error = FT_Load_Glyph(self->face, index, load_flags);
if (error)
return geterror(error);
glyph = self->face->glyph;
temp = (glyph->bitmap.rows - glyph->bitmap_top);
if (temp > ascender)
ascender = temp;
}
for (x = i = 0; font_getchar(string, i, &ch); i++) {
if (i == 0 && self->face->glyph->metrics.horiBearingX < 0)
x = -PIXEL(self->face->glyph->metrics.horiBearingX);
index = FT_Get_Char_Index(self->face, ch);
if (kerning && last_index && index) {
FT_Vector delta;
FT_Get_Kerning(self->face, last_index, index, ft_kerning_default,
&delta);
x += delta.x >> 6;
}
error = FT_Load_Glyph(self->face, index, load_flags);
if (error)
return geterror(error);
glyph = self->face->glyph;
int xx, x0, x1;
source = (unsigned char*) glyph->bitmap.buffer;
xx = x + glyph->bitmap_left;
x0 = 0;
x1 = glyph->bitmap.width;
if (xx < 0)
x0 = -xx;
if (xx + x1 > im->xsize)
x1 = im->xsize - xx;
if (mask) {
/* use monochrome mask (on palette images, etc) */
for (y = 0; y < glyph->bitmap.rows; y++) {
int yy = y + im->ysize - (PIXEL(glyph->metrics.horiBearingY) + ascender);
if (yy >= 0 && yy < im->ysize) {
/* blend this glyph into the buffer */
unsigned char *target = im->image8[yy] + xx;
int i, j, m = 128;
for (i = j = 0; j < x1; j++) {
if (j >= x0 && (source[i] & m))
target[j] = 255;
if (!(m >>= 1)) {
m = 128;
i++;
}
}
}
source += glyph->bitmap.pitch;
}
} else {
/* use antialiased rendering */
for (y = 0; y < glyph->bitmap.rows; y++) {
int yy = y + im->ysize - (PIXEL(glyph->metrics.horiBearingY) + ascender);
if (yy >= 0 && yy < im->ysize) {
/* blend this glyph into the buffer */
int i;
unsigned char *target = im->image8[yy] + xx;
for (i = x0; i < x1; i++) {
if (target[i] < source[i])
target[i] = source[i];
}
}
source += glyph->bitmap.pitch;
}
}
x += PIXEL(glyph->metrics.horiAdvance);
last_index = index;
}
Py_RETURN_NONE;
}
static void
font_dealloc(FontObject* self)
{
FT_Done_Face(self->face);
PyObject_Del(self);
}
static PyMethodDef font_methods[] = {
{"render", (PyCFunction) font_render, METH_VARARGS},
{"getsize", (PyCFunction) font_getsize, METH_VARARGS},
{"getabc", (PyCFunction) font_getabc, METH_VARARGS},
{NULL, NULL}
};
static PyObject*
font_getattr_family(FontObject* self, void* closure)
{
#if PY_VERSION_HEX >= 0x03000000
if (self->face->family_name)
return PyUnicode_FromString(self->face->family_name);
#else
if (self->face->family_name)
return PyString_FromString(self->face->family_name);
#endif
Py_RETURN_NONE;
}
static PyObject*
font_getattr_style(FontObject* self, void* closure)
{
#if PY_VERSION_HEX >= 0x03000000
if (self->face->style_name)
return PyUnicode_FromString(self->face->style_name);
#else
if (self->face->style_name)
return PyString_FromString(self->face->style_name);
#endif
Py_RETURN_NONE;
}
static PyObject*
font_getattr_ascent(FontObject* self, void* closure)
{
return PyInt_FromLong(PIXEL(self->face->size->metrics.ascender));
}
static PyObject*
font_getattr_descent(FontObject* self, void* closure)
{
return PyInt_FromLong(-PIXEL(self->face->size->metrics.descender));
}
static PyObject*
font_getattr_glyphs(FontObject* self, void* closure)
{
return PyInt_FromLong(self->face->num_glyphs);
}
static struct PyGetSetDef font_getsetters[] = {
{ "family", (getter) font_getattr_family },
{ "style", (getter) font_getattr_style },
{ "ascent", (getter) font_getattr_ascent },
{ "descent", (getter) font_getattr_descent },
{ "glyphs", (getter) font_getattr_glyphs },
{ NULL }
};
static PyTypeObject Font_Type = {
PyVarObject_HEAD_INIT(NULL, 0)
"Font", sizeof(FontObject), 0,
/* methods */
(destructor)font_dealloc, /* tp_dealloc */
0, /* tp_print */
0, /*tp_getattr*/
0, /*tp_setattr*/
0, /*tp_compare*/
0, /*tp_repr*/
0, /*tp_as_number */
0, /*tp_as_sequence */
0, /*tp_as_mapping */
0, /*tp_hash*/
0, /*tp_call*/
0, /*tp_str*/
0, /*tp_getattro*/
0, /*tp_setattro*/
0, /*tp_as_buffer*/
Py_TPFLAGS_DEFAULT, /*tp_flags*/
0, /*tp_doc*/
0, /*tp_traverse*/
0, /*tp_clear*/
0, /*tp_richcompare*/
0, /*tp_weaklistoffset*/
0, /*tp_iter*/
0, /*tp_iternext*/
font_methods, /*tp_methods*/
0, /*tp_members*/
font_getsetters, /*tp_getset*/
};
static PyMethodDef _functions[] = {
{"getfont", (PyCFunction) getfont, METH_VARARGS|METH_KEYWORDS},
{NULL, NULL}
};
static int
setup_module(PyObject* m) {
PyObject* d;
PyObject* v;
int major, minor, patch;
d = PyModule_GetDict(m);
/* Ready object type */
PyType_Ready(&Font_Type);
if (FT_Init_FreeType(&library))
return 0; /* leave it uninitalized */
FT_Library_Version(library, &major, &minor, &patch);
#if PY_VERSION_HEX >= 0x03000000
v = PyUnicode_FromFormat("%d.%d.%d", major, minor, patch);
#else
v = PyString_FromFormat("%d.%d.%d", major, minor, patch);
#endif
PyDict_SetItemString(d, "freetype2_version", v);
return 0;
}
#if PY_VERSION_HEX >= 0x03000000
PyMODINIT_FUNC
PyInit__imagingft(void) {
PyObject* m;
static PyModuleDef module_def = {
PyModuleDef_HEAD_INIT,
"_imagingft", /* m_name */
NULL, /* m_doc */
-1, /* m_size */
_functions, /* m_methods */
};
m = PyModule_Create(&module_def);
if (setup_module(m) < 0)
return NULL;
return m;
}
#else
PyMODINIT_FUNC
init_imagingft(void)
{
PyObject* m = Py_InitModule("_imagingft", _functions);
setup_module(m);
}
#endif
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