matplotlib/src/ft2font.cpp at pre-commit · ianhi/matplotlib · GitHub

Repository navigation

History

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

/* -*- mode: c++; c-basic-offset: 4 -*- */

#define NO_IMPORT_ARRAY

#include <algorithm>

#include <sstream>

#include <stdexcept>

#include <string>

#include "ft2font.h"

#include "mplutils.h"

#include "numpy_cpp.h"

#include "py_exceptions.h"

#ifndef M_PI

#define M_PI 3.14159265358979323846264338328

#endif

/**

To improve the hinting of the fonts, this code uses a hack

presented here:

http://agg.sourceforge.net/antigrain.com/research/font_rasterization/index.html

The idea is to limit the effect of hinting in the x-direction, while

preserving hinting in the y-direction. Since freetype does not

support this directly, the dpi in the x-direction is set higher than

in the y-direction, which affects the hinting grid. Then, a global

transform is placed on the font to shrink it back to the desired

size. While it is a bit surprising that the dpi setting affects

hinting, whereas the global transform does not, this is documented

behavior of FreeType, and therefore hopefully unlikely to change.

The FreeType 2 tutorial says:

NOTE: The transformation is applied to every glyph that is

loaded through FT_Load_Glyph and is completely independent of

any hinting process. This means that you won't get the same

results if you load a glyph at the size of 24 pixels, or a glyph

at the size at 12 pixels scaled by 2 through a transform,

because the hints will have been computed differently (except

you have disabled hints).

FT_Library _ft2Library;

void throw_ft_error(std::string message, FT_Error error) {

std::ostringstream os("");

os << message << " (error code 0x" << std::hex << error << ")";

throw std::runtime_error(os.str());

}

FT2Image::FT2Image() : m_dirty(true), m_buffer(NULL), m_width(0), m_height(0)

{

}

FT2Image::FT2Image(unsigned long width, unsigned long height)

: m_dirty(true), m_buffer(NULL), m_width(0), m_height(0)

{

resize(width, height);

}

FT2Image::~FT2Image()

{

delete[] m_buffer;

}

void FT2Image::resize(long width, long height)

{

if (width <= 0) {

width = 1;

}

if (height <= 0) {

height = 1;

}

size_t numBytes = width * height;

if ((unsigned long)width != m_width || (unsigned long)height != m_height) {

if (numBytes > m_width * m_height) {

delete[] m_buffer;

m_buffer = NULL;

m_buffer = new unsigned char[numBytes];

}

m_width = (unsigned long)width;

m_height = (unsigned long)height;

}

if (numBytes && m_buffer) {

memset(m_buffer, 0, numBytes);

}

m_dirty = true;

}

void FT2Image::draw_bitmap(FT_Bitmap *bitmap, FT_Int x, FT_Int y)

{

FT_Int image_width = (FT_Int)m_width;

FT_Int image_height = (FT_Int)m_height;

FT_Int char_width = bitmap->width;

FT_Int char_height = bitmap->rows;

FT_Int x1 = std::min(std::max(x, 0), image_width);

FT_Int y1 = std::min(std::max(y, 0), image_height);

FT_Int x2 = std::min(std::max(x + char_width, 0), image_width);

FT_Int y2 = std::min(std::max(y + char_height, 0), image_height);

FT_Int x_start = std::max(0, -x);

FT_Int y_offset = y1 - std::max(0, -y);

if (bitmap->pixel_mode == FT_PIXEL_MODE_GRAY) {

for (FT_Int i = y1; i < y2; ++i) {

unsigned char *dst = m_buffer + (i * image_width + x1);

unsigned char *src = bitmap->buffer + (((i - y_offset) * bitmap->pitch) + x_start);

for (FT_Int j = x1; j < x2; ++j, ++dst, ++src)

*dst |= *src;

}

} else if (bitmap->pixel_mode == FT_PIXEL_MODE_MONO) {

for (FT_Int i = y1; i < y2; ++i) {

unsigned char *dst = m_buffer + (i * image_width + x1);

unsigned char *src = bitmap->buffer + ((i - y_offset) * bitmap->pitch);

for (FT_Int j = x1; j < x2; ++j, ++dst) {

int x = (j - x1 + x_start);

int val = *(src + (x >> 3)) & (1 << (7 - (x & 0x7)));

*dst = val ? 255 : *dst;

}

} else {

throw std::runtime_error("Unknown pixel mode");

}

m_dirty = true;

}

void FT2Image::draw_rect(unsigned long x0, unsigned long y0, unsigned long x1, unsigned long y1)

{

if (x0 > m_width || x1 > m_width || y0 > m_height || y1 > m_height) {

throw std::runtime_error("Rect coords outside image bounds");

}

size_t top = y0 * m_width;

size_t bottom = y1 * m_width;

for (size_t i = x0; i < x1 + 1; ++i) {

m_buffer[i + top] = 255;

m_buffer[i + bottom] = 255;

}

for (size_t j = y0 + 1; j < y1; ++j) {

m_buffer[x0 + j * m_width] = 255;

m_buffer[x1 + j * m_width] = 255;

}

m_dirty = true;

}

void

FT2Image::draw_rect_filled(unsigned long x0, unsigned long y0, unsigned long x1, unsigned long y1)

{

x0 = std::min(x0, m_width);

y0 = std::min(y0, m_height);

x1 = std::min(x1 + 1, m_width);

y1 = std::min(y1 + 1, m_height);

for (size_t j = y0; j < y1; j++) {

for (size_t i = x0; i < x1; i++) {

m_buffer[i + j * m_width] = 255;

}

m_dirty = true;

}

static FT_UInt ft_get_char_index_or_warn(FT_Face face, FT_ULong charcode)

{

FT_UInt glyph_index = FT_Get_Char_Index(face, charcode);

if (glyph_index) {

return glyph_index;

}

PyObject *text_helpers = NULL, *tmp = NULL;

if (!(text_helpers = PyImport_ImportModule("matplotlib._text_helpers")) ||

!(tmp = PyObject_CallMethod(text_helpers, "warn_on_missing_glyph", "k", charcode))) {

goto exit;

}

exit:

Py_XDECREF(text_helpers);

Py_XDECREF(tmp);

if (PyErr_Occurred()) {

throw py::exception();

}

return 0;

}

// ft_outline_decomposer should be passed to FT_Outline_Decompose. On the

// first pass, vertices and codes are set to NULL, and index is simply

// incremented for each vertex that should be inserted, so that it is set, at

// the end, to the total number of vertices. On a second pass, vertices and

// codes should point to correctly sized arrays, and index set again to zero,

// to get fill vertices and codes with the outline decomposition.

struct ft_outline_decomposer

{

int index;

double* vertices;

unsigned char* codes;

};

static int

ft_outline_move_to(FT_Vector const* to, void* user)

{

ft_outline_decomposer* d = reinterpret_cast<ft_outline_decomposer*>(user);

if (d->codes) {

if (d->index) {

// Appending CLOSEPOLY is important to make patheffects work.

*(d->vertices++) = 0;

*(d->codes++) = CLOSEPOLY;

}

*(d->vertices++) = to->x / 64.;

*(d->vertices++) = to->y / 64.;

*(d->codes++) = MOVETO;

}

d->index += d->index ? 2 : 1;

return 0;

}

static int

ft_outline_line_to(FT_Vector const* to, void* user)

{

ft_outline_decomposer* d = reinterpret_cast<ft_outline_decomposer*>(user);

if (d->codes) {

*(d->vertices++) = to->x / 64.;

*(d->vertices++) = to->y / 64.;

*(d->codes++) = LINETO;

}

d->index++;

return 0;

}

static int

ft_outline_conic_to(FT_Vector const* control, FT_Vector const* to, void* user)

{

ft_outline_decomposer* d = reinterpret_cast<ft_outline_decomposer*>(user);

if (d->codes) {

*(d->vertices++) = control->x / 64.;

*(d->vertices++) = control->y / 64.;

*(d->vertices++) = to->x / 64.;

*(d->vertices++) = to->y / 64.;

*(d->codes++) = CURVE3;

}

d->index += 2;

return 0;

}

static int

ft_outline_cubic_to(

FT_Vector const* c1, FT_Vector const* c2, FT_Vector const* to, void* user)

{

ft_outline_decomposer* d = reinterpret_cast<ft_outline_decomposer*>(user);

if (d->codes) {

*(d->vertices++) = c1->x / 64.;

*(d->vertices++) = c1->y / 64.;

*(d->vertices++) = c2->x / 64.;

*(d->vertices++) = c2->y / 64.;

*(d->vertices++) = to->x / 64.;

*(d->vertices++) = to->y / 64.;

*(d->codes++) = CURVE4;

}

d->index += 3;

return 0;

}

static FT_Outline_Funcs ft_outline_funcs = {

ft_outline_move_to,

ft_outline_line_to,

ft_outline_conic_to,

ft_outline_cubic_to};

PyObject*

FT2Font::get_path()

{

if (!face->glyph) {

PyErr_SetString(PyExc_RuntimeError, "No glyph loaded");

return NULL;

}

ft_outline_decomposer decomposer = {};

if (FT_Error error =

FT_Outline_Decompose(

&face->glyph->outline, &ft_outline_funcs, &decomposer)) {

PyErr_Format(PyExc_RuntimeError,

"FT_Outline_Decompose failed with error 0x%x", error);

return NULL;

}

if (!decomposer.index) { // Don't append CLOSEPOLY to null glyphs.

npy_intp vertices_dims[2] = { 0, 2 };

numpy::array_view<double, 2> vertices(vertices_dims);

npy_intp codes_dims[1] = { 0 };

numpy::array_view<unsigned char, 1> codes(codes_dims);

return Py_BuildValue("NN", vertices.pyobj(), codes.pyobj());

}

npy_intp vertices_dims[2] = { decomposer.index + 1, 2 };

numpy::array_view<double, 2> vertices(vertices_dims);

npy_intp codes_dims[1] = { decomposer.index + 1 };

numpy::array_view<unsigned char, 1> codes(codes_dims);

decomposer.index = 0;

decomposer.vertices = vertices.data();

decomposer.codes = codes.data();

if (FT_Error error =

FT_Outline_Decompose(

&face->glyph->outline, &ft_outline_funcs, &decomposer)) {

PyErr_Format(PyExc_RuntimeError,

"FT_Outline_Decompose failed with error 0x%x", error);

return NULL;

}

*(decomposer.vertices++) = 0;

*(decomposer.codes++) = CLOSEPOLY;

return Py_BuildValue("NN", vertices.pyobj(), codes.pyobj());

}

FT2Font::FT2Font(FT_Open_Args &open_args, long hinting_factor_) : image(), face(NULL)

{

clear();

FT_Error error = FT_Open_Face(_ft2Library, &open_args, 0, &face);

if (error == FT_Err_Unknown_File_Format) {

throw std::runtime_error("Can not load face. Unknown file format.");

} else if (error == FT_Err_Cannot_Open_Resource) {

throw std::runtime_error("Can not load face. Can not open resource.");

} else if (error == FT_Err_Invalid_File_Format) {

throw std::runtime_error("Can not load face. Invalid file format.");

} else if (error) {

throw_ft_error("Can not load face", error);

}

// set default kerning factor to 0, i.e., no kerning manipulation

kerning_factor = 0;

// set a default fontsize 12 pt at 72dpi

hinting_factor = hinting_factor_;

error = FT_Set_Char_Size(face, 12 * 64, 0, 72 * (unsigned int)hinting_factor, 72);

if (error) {

FT_Done_Face(face);

throw_ft_error("Could not set the fontsize", error);

}

if (open_args.stream != NULL) {

face->face_flags |= FT_FACE_FLAG_EXTERNAL_STREAM;

}

FT_Matrix transform = { 65536 / hinting_factor, 0, 0, 65536 };

FT_Set_Transform(face, &transform, 0);

}

FT2Font::~FT2Font()

{

for (size_t i = 0; i < glyphs.size(); i++) {

FT_Done_Glyph(glyphs[i]);

}

if (face) {

FT_Done_Face(face);

}

void FT2Font::clear()

{

pen.x = 0;

pen.y = 0;

for (size_t i = 0; i < glyphs.size(); i++) {

FT_Done_Glyph(glyphs[i]);

}

glyphs.clear();

}

void FT2Font::set_size(double ptsize, double dpi)

{

FT_Error error = FT_Set_Char_Size(

face, (FT_F26Dot6)(ptsize * 64), 0, (FT_UInt)(dpi * hinting_factor), (FT_UInt)dpi);

if (error) {

throw_ft_error("Could not set the fontsize", error);

}

FT_Matrix transform = { 65536 / hinting_factor, 0, 0, 65536 };

FT_Set_Transform(face, &transform, 0);

}

void FT2Font::set_charmap(int i)

{

if (i >= face->num_charmaps) {

throw std::runtime_error("i exceeds the available number of char maps");

}

FT_CharMap charmap = face->charmaps[i];

if (FT_Error error = FT_Set_Charmap(face, charmap)) {

throw_ft_error("Could not set the charmap", error);

}

void FT2Font::select_charmap(unsigned long i)

{

if (FT_Error error = FT_Select_Charmap(face, (FT_Encoding)i)) {

throw_ft_error("Could not set the charmap", error);

}

int FT2Font::get_kerning(FT_UInt left, FT_UInt right, FT_UInt mode)

{

if (!FT_HAS_KERNING(face)) {

return 0;

}

FT_Vector delta;

if (!FT_Get_Kerning(face, left, right, mode, &delta)) {

return (int)(delta.x) / (hinting_factor << kerning_factor);

} else {

return 0;

}

void FT2Font::set_kerning_factor(int factor)

{

kerning_factor = factor;

}

void FT2Font::set_text(

size_t N, uint32_t *codepoints, double angle, FT_Int32 flags, std::vector<double> &xys)

{

FT_Matrix matrix; /* transformation matrix */

angle = angle / 360.0 * 2 * M_PI;

// this computes width and height in subpixels so we have to divide by 64

matrix.xx = (FT_Fixed)(cos(angle) * 0x10000L);

matrix.xy = (FT_Fixed)(-sin(angle) * 0x10000L);

matrix.yx = (FT_Fixed)(sin(angle) * 0x10000L);

matrix.yy = (FT_Fixed)(cos(angle) * 0x10000L);

FT_Bool use_kerning = FT_HAS_KERNING(face);

FT_UInt previous = 0;

clear();

bbox.xMin = bbox.yMin = 32000;

bbox.xMax = bbox.yMax = -32000;

for (unsigned int n = 0; n < N; n++) {

FT_UInt glyph_index;

FT_BBox glyph_bbox;

FT_Pos last_advance;

glyph_index = ft_get_char_index_or_warn(face, codepoints[n]);

// retrieve kerning distance and move pen position

if (use_kerning && previous && glyph_index) {

FT_Vector delta;

FT_Get_Kerning(face, previous, glyph_index, FT_KERNING_DEFAULT, &delta);

pen.x += delta.x / (hinting_factor << kerning_factor);

}

if (FT_Error error = FT_Load_Glyph(face, glyph_index, flags)) {

throw_ft_error("Could not load glyph", error);

}

// ignore errors, jump to next glyph

// extract glyph image and store it in our table

FT_Glyph thisGlyph;

if (FT_Error error = FT_Get_Glyph(face->glyph, &thisGlyph)) {

throw_ft_error("Could not get glyph", error);

}

// ignore errors, jump to next glyph

last_advance = face->glyph->advance.x;

FT_Glyph_Transform(thisGlyph, 0, &pen);

FT_Glyph_Transform(thisGlyph, &matrix, 0);

xys.push_back(pen.x);

xys.push_back(pen.y);

FT_Glyph_Get_CBox(thisGlyph, FT_GLYPH_BBOX_SUBPIXELS, &glyph_bbox);

bbox.xMin = std::min(bbox.xMin, glyph_bbox.xMin);

bbox.xMax = std::max(bbox.xMax, glyph_bbox.xMax);

bbox.yMin = std::min(bbox.yMin, glyph_bbox.yMin);

bbox.yMax = std::max(bbox.yMax, glyph_bbox.yMax);

pen.x += last_advance;

previous = glyph_index;

glyphs.push_back(thisGlyph);

}

FT_Vector_Transform(&pen, &matrix);

advance = pen.x;

if (bbox.xMin > bbox.xMax) {

bbox.xMin = bbox.yMin = bbox.xMax = bbox.yMax = 0;

}

void FT2Font::load_char(long charcode, FT_Int32 flags)

{

FT_UInt glyph_index = ft_get_char_index_or_warn(face, (FT_ULong)charcode);

if (FT_Error error = FT_Load_Glyph(face, glyph_index, flags)) {

throw_ft_error("Could not load charcode", error);

}

FT_Glyph thisGlyph;

if (FT_Error error = FT_Get_Glyph(face->glyph, &thisGlyph)) {

throw_ft_error("Could not get glyph", error);

}

glyphs.push_back(thisGlyph);

}

void FT2Font::load_glyph(FT_UInt glyph_index, FT_Int32 flags)

{

if (FT_Error error = FT_Load_Glyph(face, glyph_index, flags)) {

throw_ft_error("Could not load glyph", error);

}

FT_Glyph thisGlyph;

if (FT_Error error = FT_Get_Glyph(face->glyph, &thisGlyph)) {

throw_ft_error("Could not get glyph", error);

}

glyphs.push_back(thisGlyph);

}

void FT2Font::get_width_height(long *width, long *height)

{

*width = advance;

*height = bbox.yMax - bbox.yMin;

}

long FT2Font::get_descent()

{

return -bbox.yMin;

}

void FT2Font::get_bitmap_offset(long *x, long *y)

{

*x = bbox.xMin;

*y = 0;

}

void FT2Font::draw_glyphs_to_bitmap(bool antialiased)

{

size_t width = (bbox.xMax - bbox.xMin) / 64 + 2;

size_t height = (bbox.yMax - bbox.yMin) / 64 + 2;

image.resize(width, height);

for (size_t n = 0; n < glyphs.size(); n++) {

FT_Error error = FT_Glyph_To_Bitmap(

&glyphs[n], antialiased ? FT_RENDER_MODE_NORMAL : FT_RENDER_MODE_MONO, 0, 1);

if (error) {

throw_ft_error("Could not convert glyph to bitmap", error);

}

FT_BitmapGlyph bitmap = (FT_BitmapGlyph)glyphs[n];

// now, draw to our target surface (convert position)

// bitmap left and top in pixel, string bbox in subpixel

FT_Int x = (FT_Int)(bitmap->left - (bbox.xMin / 64.));

FT_Int y = (FT_Int)((bbox.yMax / 64.) - bitmap->top + 1);

image.draw_bitmap(&bitmap->bitmap, x, y);

}

void FT2Font::get_xys(bool antialiased, std::vector<double> &xys)

{

for (size_t n = 0; n < glyphs.size(); n++) {

FT_Error error = FT_Glyph_To_Bitmap(

&glyphs[n], antialiased ? FT_RENDER_MODE_NORMAL : FT_RENDER_MODE_MONO, 0, 1);

if (error) {

throw_ft_error("Could not convert glyph to bitmap", error);

}

FT_BitmapGlyph bitmap = (FT_BitmapGlyph)glyphs[n];

// bitmap left and top in pixel, string bbox in subpixel

FT_Int x = (FT_Int)(bitmap->left - bbox.xMin / 64.);

FT_Int y = (FT_Int)(bbox.yMax / 64. - bitmap->top + 1);

// make sure the index is non-neg

x = x < 0 ? 0 : x;

y = y < 0 ? 0 : y;

xys.push_back(x);

xys.push_back(y);

}

void FT2Font::draw_glyph_to_bitmap(FT2Image &im, int x, int y, size_t glyphInd, bool antialiased)

{

FT_Vector sub_offset;

sub_offset.x = 0; // int((xd - (double)x) * 64.0);

sub_offset.y = 0; // int((yd - (double)y) * 64.0);

if (glyphInd >= glyphs.size()) {

throw std::runtime_error("glyph num is out of range");

}

FT_Error error = FT_Glyph_To_Bitmap(

&glyphs[glyphInd],

antialiased ? FT_RENDER_MODE_NORMAL : FT_RENDER_MODE_MONO,

&sub_offset, // additional translation

1 // destroy image

);

if (error) {

throw_ft_error("Could not convert glyph to bitmap", error);

}

FT_BitmapGlyph bitmap = (FT_BitmapGlyph)glyphs[glyphInd];

im.draw_bitmap(&bitmap->bitmap, x + bitmap->left, y);

}

void FT2Font::get_glyph_name(unsigned int glyph_number, char *buffer)

{

if (!FT_HAS_GLYPH_NAMES(face)) {

/* Note that this generated name must match the name that

is generated by ttconv in ttfont_CharStrings_getname. */

PyOS_snprintf(buffer, 128, "uni%08x", glyph_number);

} else {

if (FT_Error error = FT_Get_Glyph_Name(face, glyph_number, buffer, 128)) {

throw_ft_error("Could not get glyph names", error);

}

long FT2Font::get_name_index(char *name)

{

return FT_Get_Name_Index(face, (FT_String *)name);

}

matplotlib/src/ft2font.cpp at pre-commit · ianhi/matplotlib · GitHub

Repository navigation

Expand file tree

Breadcrumbs

ft2font.cpp

Latest commit

History

Breadcrumbs

ft2font.cpp

File metadata and controls