gecko-dev/gfx/2d/unittest/TestCairo.cpp

/* Any copyright is dedicated to the Public Domain.
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

#include "cairo.h"

#include "gtest/gtest.h"

namespace mozilla {
namespace layers {

static void TryCircle(double centerX, double centerY, double radius) {
  printf("TestCairo:TryArcs centerY %f, radius %f\n", centerY, radius);

  cairo_surface_t* surf =
      cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 8, 21);
  ASSERT_TRUE(surf != nullptr);

  cairo_t* cairo = cairo_create(surf);
  ASSERT_TRUE(cairo != nullptr);

  cairo_set_antialias(cairo, CAIRO_ANTIALIAS_NONE);
  cairo_arc(cairo, 0.0, centerY, radius, 0.0, 6.2831853071795862);
  cairo_fill_preserve(cairo);

  cairo_surface_destroy(surf);
  cairo_destroy(cairo);
}

TEST(Cairo, Simple)
{
  TryCircle(0.0, 0.0, 14.0);
  TryCircle(0.0, 1.0, 22.4);
  TryCircle(1.0, 0.0, 1422.4);
  TryCircle(1.0, 1.0, 3422.4);
  TryCircle(-10.0, 1.0, -2);
}

TEST(Cairo, Bug825721)
{
  // OK:
  TryCircle(0.0, 0.0, 8761126469220696064.0);
  TryCircle(0.0, 1.0, 8761126469220696064.0);

  // OK:
  TryCircle(1.0, 0.0, 5761126469220696064.0);

  // This was the crash in 825721.  Note that centerY has to be non-zero,
  // and radius has to be not only large, but in particular range.
  // 825721 has a band-aid fix, where the crash is inevitable, but does
  // not fix the cause.  The same code crashes in cairo standalone.
  TryCircle(0.0, 1.0, 5761126469220696064.0);
}

TEST(Cairo, Bug1063486)
{
  double x1, y1, x2, y2;
  const double epsilon = .01;

  cairo_surface_t* surf = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, 1, 1);
  ASSERT_TRUE(surf != nullptr);

  cairo_t* cairo = cairo_create(surf);
  ASSERT_TRUE(cairo != nullptr);

  printf("Path 1\n");
  cairo_move_to(cairo, -20, -10);
  cairo_line_to(cairo, 20, -10);
  cairo_line_to(cairo, 20, 10);
  cairo_curve_to(cairo, 10, 10, -10, 10, -20, 10);
  cairo_curve_to(cairo, -30, 10, -30, -10, -20, -10);

  cairo_path_extents(cairo, &x1, &y1, &x2, &y2);

  ASSERT_LT(std::abs(-27.5 - x1), epsilon);  // the failing coordinate
  ASSERT_LT(std::abs(-10 - y1), epsilon);
  ASSERT_LT(std::abs(20 - x2), epsilon);
  ASSERT_LT(std::abs(10 - y2), epsilon);

  printf("Path 2\n");
  cairo_new_path(cairo);
  cairo_move_to(cairo, 10, 30);
  cairo_line_to(cairo, 90, 30);
  cairo_curve_to(cairo, 30, 30, 30, 30, 10, 30);
  cairo_curve_to(cairo, 0, 30, 0, 0, 30, 5);

  cairo_path_extents(cairo, &x1, &y1, &x2, &y2);

  ASSERT_LT(std::abs(4.019531 - x1), epsilon);  // the failing coordinate
  ASSERT_LT(std::abs(4.437500 - y1), epsilon);
  ASSERT_LT(std::abs(90. - x2), epsilon);
  ASSERT_LT(std::abs(30. - y2), epsilon);

  cairo_surface_destroy(surf);
  cairo_destroy(cairo);
}

}  // namespace layers
}  // namespace mozilla