Parameters for controlling image comparison tests. More...

#include "donner/svg/renderer/tests/ImageComparisonTestFixture.h"

Collaboration diagram for donner::svg::ImageComparisonParams:

Public Member Functions
ImageComparisonParams &	disableDebugSkpOnFailure ()
	Disables saving of .skp files on test failure.
ImageComparisonParams &	includeAntiAliasingDifferences ()
	Counts anti-aliased pixel differences as mismatches.
ImageComparisonParams &	enableGoldenUpdateFromEnv ()
	Enables updating golden images based on an environment variable.
ImageComparisonParams &	setCanvasSize (int width, int height)
	Sets a custom canvas size for rendering.
ImageComparisonParams &	disableBackend (RendererBackend backend, std::string_view reason=std::string_view())
	Disables one backend for this test case.
ImageComparisonParams &	requireFeature (RendererBackendFeature feature, std::string_view reason=std::string_view())
	Requires a renderer feature for this test case.
ImageComparisonParams &	withSimpleTextMaxPixels (int pixels)
	Sets a separate maxMismatchedPixels for simple text (without HarfBuzz shaping).
ImageComparisonParams &	withMaxPixelsDifferent (int pixels)
	Sets the max mismatched pixels for this test case.
ImageComparisonParams &	onlyTextFull ()
	Skip this test entirely when running without HarfBuzz (simple text).
int	effectiveMaxMismatchedPixels () const
	Returns the effective maxMismatchedPixels for the active text config.
bool	shouldSkip () const
	Returns true if this test should be skipped for the active text config.

Static Public Member Functions
static ImageComparisonParams	Skip ()
	Creates parameters to skip a test.
static ImageComparisonParams	RenderOnly ()
	Creates parameters that render the test but skip pixel comparison.
static ImageComparisonParams	WithThreshold (float threshold, int maxMismatchedPixels=kDefaultMismatchedPixels)
	Creates parameters with a specific threshold and maximum mismatched pixels.
static ImageComparisonParams	WithGoldenOverride (std::string_view filename, float threshold=kDefaultThreshold)
	Creates parameters with an overridden golden image filename.

Public Attributes
float	threshold = kDefaultThreshold
	Maximum allowed difference per pixel (0.0 to 1.0).
int	maxMismatchedPixels = kDefaultMismatchedPixels
	Maximum number of pixels that can exceed the threshold.
int	simpleTextMaxMismatchedPixels = -1
	Override for maxMismatchedPixels when running without HarfBuzz text shaping (DONNER_TEXT_FULL not defined). -1 means use maxMismatchedPixels for all configs.
bool	skipSimpleText = false
	If true, skip this test when running without HarfBuzz (simple text).
bool	includeAntiAliasing = false
	If true, count anti-aliased pixels as mismatches instead of suppressing them.
bool	skip = false
	If true, skip this test case.
bool	saveDebugSkpOnFailure = true
	If true, save a .skp file for debugging when a test fails.
bool	updateGoldenFromEnv = false
	If true, allow updating golden images via an environment variable.
bool	showTerminalPreview = true
	If true, emit a terminal preview grid when comparisons fail.
std::optional< Vector2i >	canvasSize
	Optional canvas size override, which determines the size of the rendered image.
std::string_view	overrideGoldenFilename
	Optional filename to use for the golden image, overriding the default.
bool	allowSkia = true
	If false, skip the test when the active backend is Skia.
bool	allowTinySkia = true
	If false, skip the test when the active backend is TinySkia.
bool	allowGeode = true
	If false, skip the test when the active backend is Geode.
uint32_t	requiredFeatures = 0
	Bitmask of required backend features, built from RendererBackendFeatureMask.
std::string_view	backendRequirementReason
	Human-readable reason used when backend restrictions cause a skip.
bool	renderOnly = false
	If true, render but skip the pixel comparison. Used for tests where the output is implementation-defined or UB, but we still want to verify rendering stability.

Detailed Description

Parameters for controlling image comparison tests.

This struct allows customization of various aspects of the image comparison process, such as error thresholds, skipping tests, and overriding golden image filenames.

Member Function Documentation

◆ disableBackend()

ImageComparisonParams & donner::svg::ImageComparisonParams::disableBackend	(	RendererBackend	backend,
		std::string_view	reason = std::string_view() )

inline

Disables one backend for this test case.

Parameters

backend	The backend to disable.
reason	Optional human-readable skip reason.

Returns: Reference to this ImageComparisonParams object.

◆ disableDebugSkpOnFailure()

ImageComparisonParams & donner::svg::ImageComparisonParams::disableDebugSkpOnFailure ( )

inline

Disables saving of .skp files on test failure.

Returns: Reference to this ImageComparisonParams object.

◆ enableGoldenUpdateFromEnv()

ImageComparisonParams & donner::svg::ImageComparisonParams::enableGoldenUpdateFromEnv ( )

inline

Enables updating golden images based on an environment variable.

Returns: Reference to this ImageComparisonParams object.

◆ includeAntiAliasingDifferences()

ImageComparisonParams & donner::svg::ImageComparisonParams::includeAntiAliasingDifferences ( )

inline

Counts anti-aliased pixel differences as mismatches.

Returns: Reference to this ImageComparisonParams object.

◆ onlyTextFull()

ImageComparisonParams & donner::svg::ImageComparisonParams::onlyTextFull ( )

inline

Skip this test entirely when running without HarfBuzz (simple text).

Use this for tests that require text-full features (e.g., color emoji fonts that can't be loaded by stb_truetype at all).

Returns: Reference to this ImageComparisonParams object.

◆ RenderOnly()

ImageComparisonParams donner::svg::ImageComparisonParams::RenderOnly ( )

inlinestatic

Creates parameters that render the test but skip pixel comparison.

Used for tests where the output is implementation-defined or has expected variance, but we want to verify that rendering completes without crashing.

Returns: ImageComparisonParams configured for render-only mode.

◆ requireFeature()

ImageComparisonParams & donner::svg::ImageComparisonParams::requireFeature	(	RendererBackendFeature	feature,
		std::string_view	reason = std::string_view() )

inline

Requires a renderer feature for this test case.

Parameters

feature	The feature to require.
reason	Optional human-readable skip reason.

Returns: Reference to this ImageComparisonParams object.

◆ setCanvasSize()

ImageComparisonParams & donner::svg::ImageComparisonParams::setCanvasSize	(	int	width,
		int	height )

inline

Sets a custom canvas size for rendering.

Parameters

width	The width of the canvas.
height	The height of the canvas.

Returns: Reference to this ImageComparisonParams object.

◆ Skip()

ImageComparisonParams donner::svg::ImageComparisonParams::Skip ( )

inlinestatic

Creates parameters to skip a test.

Returns: ImageComparisonParams configured to skip.

◆ WithGoldenOverride()

ImageComparisonParams donner::svg::ImageComparisonParams::WithGoldenOverride	(	std::string_view	filename,
		float	threshold = kDefaultThreshold )

inlinestatic

Creates parameters with an overridden golden image filename.

Parameters

filename	The filename to use for the golden image.
threshold	Optional per-pixel difference threshold to use with the override.

Returns: ImageComparisonParams configured with the golden override.

◆ withMaxPixelsDifferent()

ImageComparisonParams & donner::svg::ImageComparisonParams::withMaxPixelsDifferent ( int pixels )

inline

Sets the max mismatched pixels for this test case.

Parameters

pixels The max mismatched pixels.

Returns: Reference to this ImageComparisonParams object.

◆ withSimpleTextMaxPixels()

ImageComparisonParams & donner::svg::ImageComparisonParams::withSimpleTextMaxPixels ( int pixels )

inline

Sets a separate maxMismatchedPixels for simple text (without HarfBuzz shaping).

When DONNER_TEXT_FULL is not defined, this value is used instead of maxMismatchedPixels. This allows tests that require text shaping (combining marks, ligatures, etc.) to have a looser threshold for simple text while keeping a strict threshold for HarfBuzz.

Parameters

pixels The max mismatched pixels for simple text.

Returns: Reference to this ImageComparisonParams object.

◆ WithThreshold()

ImageComparisonParams donner::svg::ImageComparisonParams::WithThreshold	(	float	threshold,
		int	maxMismatchedPixels = kDefaultMismatchedPixels )

inlinestatic

Creates parameters with a specific threshold and maximum mismatched pixels.

Parameters

threshold	The per-pixel difference threshold.
maxMismatchedPixels	The maximum number of pixels allowed to mismatch.

Returns: ImageComparisonParams configured with the specified thresholds.

The documentation for this struct was generated from the following file:

donner/svg/renderer/tests/ImageComparisonTestFixture.h

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Member Function Documentation

◆ disableBackend()

◆ disableDebugSkpOnFailure()

◆ enableGoldenUpdateFromEnv()

◆ includeAntiAliasingDifferences()

◆ onlyTextFull()

◆ RenderOnly()

◆ requireFeature()

◆ setCanvasSize()

◆ Skip()

◆ WithGoldenOverride()

◆ withMaxPixelsDifferent()

◆ withSimpleTextMaxPixels()

◆ WithThreshold()