aiden/video-shader-toys
1
0
Fork 0
Code Issues Pull Requests Actions Releases 5 Wiki Activity

Font working

Browse Source
This commit is contained in:
Aiden
2026-05-05 23:47:08 +10:00
parent 3e8b472f74
commit 62c3ded1f8
9 changed files with 220 additions and 36 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
README.md
View File

@@ -236,7 +236,10 @@ Fonts
genlock
Logs
anamorphic desqueeze
solid color layer
refactor, cleanup of source files
display URL (Maybe clicakable) for control in the windows app (Not on the output)
Sound shader as seperate .slang in shader package?
runtime date time
Add a value control to the color wheels
![alt text](image.png)

154
apps/LoopThroughWithOpenGLCompositing/OpenGLComposite.cpp
View File

@@ -47,6 +47,7 @@
#include <cstdint>
#include <cstring>
#include <cctype>
#include <fstream>
#include <gdiplus.h>
#include <wincodec.h>
#include <limits>
@@ -106,6 +107,31 @@ const char* kDecodeFragmentShaderSource =
" fragColor = rec709YCbCr2rgba(ySample, macroPixel.b, macroPixel.r, 1.0);\n"
"}\n";
class GdiplusSession
{
public:
GdiplusSession()
{
Gdiplus::GdiplusStartupInput startupInput;
mStarted = Gdiplus::GdiplusStartup(&mToken, &startupInput, NULL) == Gdiplus::Ok;
}
~GdiplusSession()
{
if (mStarted)
Gdiplus::GdiplusShutdown(mToken);
}
GdiplusSession(const GdiplusSession&) = delete;
GdiplusSession& operator=(const GdiplusSession&) = delete;
bool started() const { return mStarted; }
private:
ULONG_PTR mToken = 0;
bool mStarted = false;
};
void CopyErrorMessage(const std::string& message, int errorMessageSize, char* errorMessage)
{
if (!errorMessage || errorMessageSize <= 0)
@@ -191,11 +217,87 @@ std::vector<unsigned char> BuildLocalSdf(const std::vector<unsigned char>& alpha
return sdf;
}
std::vector<unsigned char> FlipTextTextureForShaderUv(const std::vector<unsigned char>& pixels, unsigned width, unsigned height)
{
std::vector<unsigned char> flipped(pixels.size(), 0);
const std::size_t stride = static_cast<std::size_t>(width) * 4;
for (unsigned y = 0; y < height; ++y)
{
const std::size_t srcOffset = static_cast<std::size_t>(y) * stride;
const std::size_t dstOffset = static_cast<std::size_t>(height - 1 - y) * stride;
std::memcpy(flipped.data() + dstOffset, pixels.data() + srcOffset, stride);
}
return flipped;
}
void WriteTextMaskDebugDump(const std::string& text, const std::vector<unsigned char>& alpha, const std::vector<unsigned char>& sdf, unsigned width, unsigned height)
{
try
{
std::filesystem::path debugDir = std::filesystem::current_path() / "runtime";
std::filesystem::create_directories(debugDir);
auto writePgm = [width, height](const std::filesystem::path& path, const std::vector<unsigned char>& gray, std::size_t stride)
{
std::ofstream out(path, std::ios::binary);
if (!out)
return;
out << "P5\n" << width << " " << height << "\n255\n";
for (unsigned y = 0; y < height; ++y)
{
for (unsigned x = 0; x < width; ++x)
out.put(static_cast<char>(gray[(static_cast<std::size_t>(y) * width + x) * stride]));
}
};
writePgm(debugDir / "text-mask-alpha-debug.pgm", alpha, 1);
writePgm(debugDir / "text-mask-sdf-debug.pgm", sdf, 4);
unsigned alphaMin = 255;
unsigned alphaMax = 0;
unsigned sdfMin = 255;
unsigned sdfMax = 0;
std::size_t alphaLit = 0;
std::size_t sdfLit = 0;
for (unsigned char value : alpha)
{
alphaMin = std::min<unsigned>(alphaMin, value);
alphaMax = std::max<unsigned>(alphaMax, value);
if (value > 0)
++alphaLit;
}
for (std::size_t index = 0; index < sdf.size(); index += 4)
{
const unsigned char value = sdf[index];
sdfMin = std::min<unsigned>(sdfMin, value);
sdfMax = std::max<unsigned>(sdfMax, value);
if (value > 127)
++sdfLit;
}
std::ostringstream message;
message << "Text mask debug for '" << text << "': alpha min/max/lit=" << alphaMin << "/" << alphaMax << "/" << alphaLit
<< ", sdf min/max/gt127=" << sdfMin << "/" << sdfMax << "/" << sdfLit << "\n";
OutputDebugStringA(message.str().c_str());
}
catch (...)
{
OutputDebugStringA("Failed to write text mask debug dump.\n");
}
}
GLint FindSamplerUniformLocation(GLuint program, const std::string& samplerName)
{
GLint location = glGetUniformLocation(program, samplerName.c_str());
if (location >= 0)
return location;
return glGetUniformLocation(program, (samplerName + "_0").c_str());
}
bool RasterizeTextSdf(const std::string& text, const std::filesystem::path& fontPath, std::vector<unsigned char>& sdf, std::string& error)
{
ULONG_PTR gdiplusToken = 0;
Gdiplus::GdiplusStartupInput startupInput;
if (Gdiplus::GdiplusStartup(&gdiplusToken, &startupInput, NULL) != Gdiplus::Ok)
GdiplusSession gdiplus;
if (!gdiplus.started())
{
error = "Could not start GDI+ for text rendering.";
return false;
@@ -210,7 +312,6 @@ bool RasterizeTextSdf(const std::string& text, const std::filesystem::path& font
{
if (fontCollection.AddFontFile(wideFontPath.c_str()) != Gdiplus::Ok)
{
Gdiplus::GdiplusShutdown(gdiplusToken);
error = "Could not load packaged font file for text rendering: " + fontPath.string();
return false;
}
@@ -218,7 +319,6 @@ bool RasterizeTextSdf(const std::string& text, const std::filesystem::path& font
const INT familyCount = fontCollection.GetFamilyCount();
if (familyCount <= 0)
{
Gdiplus::GdiplusShutdown(gdiplusToken);
error = "Packaged font did not contain a usable font family: " + fontPath.string();
return false;
}
@@ -227,7 +327,6 @@ bool RasterizeTextSdf(const std::string& text, const std::filesystem::path& font
INT found = 0;
if (fontCollection.GetFamilies(familyCount, families.get(), &found) != Gdiplus::Ok || found <= 0)
{
Gdiplus::GdiplusShutdown(gdiplusToken);
error = "Could not read the packaged font family: " + fontPath.string();
return false;
}
@@ -236,7 +335,9 @@ bool RasterizeTextSdf(const std::string& text, const std::filesystem::path& font
Gdiplus::Bitmap bitmap(kTextTextureWidth, kTextTextureHeight, PixelFormat32bppARGB);
Gdiplus::Graphics graphics(&bitmap);
graphics.Clear(Gdiplus::Color(0, 0, 0, 0));
graphics.SetCompositingMode(Gdiplus::CompositingModeSourceCopy);
graphics.Clear(Gdiplus::Color(255, 0, 0, 0));
graphics.SetCompositingMode(Gdiplus::CompositingModeSourceOver);
graphics.SetTextRenderingHint(Gdiplus::TextRenderingHintAntiAliasGridFit);
graphics.SetSmoothingMode(Gdiplus::SmoothingModeHighQuality);
Gdiplus::Font font(fontFamily, 72.0f, Gdiplus::FontStyleRegular, Gdiplus::UnitPixel);
@@ -256,11 +357,17 @@ bool RasterizeTextSdf(const std::string& text, const std::filesystem::path& font
{
Gdiplus::Color pixel;
bitmap.GetPixel(x, y, &pixel);
alpha[static_cast<std::size_t>(y) * kTextTextureWidth + x] = pixel.GetAlpha();
BYTE luminance = pixel.GetRed();
if (pixel.GetGreen() > luminance)
luminance = pixel.GetGreen();
if (pixel.GetBlue() > luminance)
luminance = pixel.GetBlue();
alpha[static_cast<std::size_t>(y) * kTextTextureWidth + x] = static_cast<unsigned char>(luminance);
}
}
sdf = BuildLocalSdf(alpha, kTextTextureWidth, kTextTextureHeight);
Gdiplus::GdiplusShutdown(gdiplusToken);
sdf = FlipTextTextureForShaderUv(sdf, kTextTextureWidth, kTextTextureHeight);
WriteTextMaskDebugDump(text, alpha, sdf, kTextTextureWidth, kTextTextureHeight);
return true;
}
@@ -1670,7 +1777,7 @@ bool OpenGLComposite::compileSingleLayerProgram(const RuntimeRenderState& state,
glUniformBlockBinding(newProgram.get(), globalParamsIndex, kGlobalParamsBindingPoint);
const unsigned historyCap = mRuntimeHost ? mRuntimeHost->GetMaxTemporalHistoryFrames() : 0;
const GLuint shaderTextureBase = kSourceHistoryTextureUnitBase + historyCap + historyCap;
const GLuint shaderTextureBase = state.isTemporal ? kSourceHistoryTextureUnitBase + historyCap + historyCap : kSourceHistoryTextureUnitBase;
glUseProgram(newProgram.get());
const GLint videoInputLocation = glGetUniformLocation(newProgram.get(), "gVideoInput");
if (videoInputLocation >= 0)
@@ -1689,14 +1796,14 @@ bool OpenGLComposite::compileSingleLayerProgram(const RuntimeRenderState& state,
}
for (std::size_t index = 0; index < textureBindings.size(); ++index)
{
const GLint textureSamplerLocation = glGetUniformLocation(newProgram.get(), textureBindings[index].samplerName.c_str());
const GLint textureSamplerLocation = FindSamplerUniformLocation(newProgram.get(), textureBindings[index].samplerName);
if (textureSamplerLocation >= 0)
glUniform1i(textureSamplerLocation, static_cast<GLint>(shaderTextureBase + static_cast<GLuint>(index)));
}
const GLuint textTextureBase = shaderTextureBase + static_cast<GLuint>(textureBindings.size());
for (std::size_t index = 0; index < textBindings.size(); ++index)
{
const GLint textSamplerLocation = glGetUniformLocation(newProgram.get(), textBindings[index].samplerName.c_str());
const GLint textSamplerLocation = FindSamplerUniformLocation(newProgram.get(), textBindings[index].samplerName);
if (textSamplerLocation >= 0)
glUniform1i(textSamplerLocation, static_cast<GLint>(textTextureBase + static_cast<GLuint>(index)));
}
@@ -1704,6 +1811,7 @@ bool OpenGLComposite::compileSingleLayerProgram(const RuntimeRenderState& state,
layerProgram.layerId = state.layerId;
layerProgram.shaderId = state.shaderId;
layerProgram.shaderTextureBase = shaderTextureBase;
layerProgram.program = newProgram.release();
layerProgram.vertexShader = newVertexShader.release();
layerProgram.fragmentShader = newFragmentShader.release();
@@ -1972,9 +2080,18 @@ bool OpenGLComposite::renderTextBindingTexture(const RuntimeRenderState& state,
if (!RasterizeTextSdf(text, fontPath, sdf, error))
return false;
GLint previousActiveTexture = 0;
GLint previousUnpackBuffer = 0;
glGetIntegerv(GL_ACTIVE_TEXTURE, &previousActiveTexture);
glGetIntegerv(GL_PIXEL_UNPACK_BUFFER_BINDING, &previousUnpackBuffer);
glActiveTexture(GL_TEXTURE0);
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, 0);
glBindTexture(GL_TEXTURE_2D, textBinding.texture);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, kTextTextureWidth, kTextTextureHeight, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, sdf.data());
glBindTexture(GL_TEXTURE_2D, 0);
glBindBuffer(GL_PIXEL_UNPACK_BUFFER, static_cast<GLuint>(previousUnpackBuffer));
glActiveTexture(static_cast<GLenum>(previousActiveTexture));
textBinding.renderedText = text;
textBinding.renderedWidth = kTextTextureWidth;
textBinding.renderedHeight = kTextTextureHeight;
@@ -1983,8 +2100,7 @@ bool OpenGLComposite::renderTextBindingTexture(const RuntimeRenderState& state,
void OpenGLComposite::bindLayerTextureAssets(const LayerProgram& layerProgram)
{
const unsigned historyCap = mRuntimeHost ? mRuntimeHost->GetMaxTemporalHistoryFrames() : 0;
const GLuint shaderTextureBase = kSourceHistoryTextureUnitBase + historyCap + historyCap;
const GLuint shaderTextureBase = layerProgram.shaderTextureBase != 0 ? layerProgram.shaderTextureBase : kSourceHistoryTextureUnitBase;
for (std::size_t index = 0; index < layerProgram.textureBindings.size(); ++index)
{
glActiveTexture(GL_TEXTURE0 + shaderTextureBase + static_cast<GLuint>(index));
@@ -2023,7 +2139,7 @@ void OpenGLComposite::destroyDecodeShaderProgram()
bool OpenGLComposite::validateTemporalTextureUnitBudget(const std::vector<RuntimeRenderState>& layerStates, std::string& error) const
{
const unsigned historyCap = mRuntimeHost ? mRuntimeHost->GetMaxTemporalHistoryFrames() : 0;
unsigned maxAssetTextures = 0;
unsigned requiredUnits = kSourceHistoryTextureUnitBase;
for (const RuntimeRenderState& state : layerStates)
{
unsigned textTextureCount = 0;
@@ -2033,12 +2149,12 @@ bool OpenGLComposite::validateTemporalTextureUnitBudget(const std::vector<Runtim
++textTextureCount;
}
const unsigned totalShaderTextures = static_cast<unsigned>(state.textureAssets.size()) + textTextureCount;
if (totalShaderTextures > maxAssetTextures)
maxAssetTextures = totalShaderTextures;
const unsigned layerRequiredUnits = kSourceHistoryTextureUnitBase + (state.isTemporal ? historyCap + historyCap : 0u) + totalShaderTextures;
if (layerRequiredUnits > requiredUnits)
requiredUnits = layerRequiredUnits;
}
GLint maxTextureUnits = 0;
glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &maxTextureUnits);
const unsigned requiredUnits = kSourceHistoryTextureUnitBase + historyCap + historyCap + maxAssetTextures;
const unsigned availableUnits = maxTextureUnits > 0 ? static_cast<unsigned>(maxTextureUnits) : 0u;
if (requiredUnits > availableUnits)
{
@@ -2327,7 +2443,7 @@ void OpenGLComposite::renderShaderProgram(GLuint sourceTexture, GLuint destinati
glActiveTexture(GL_TEXTURE0 + kSourceHistoryTextureUnitBase + historyCap + index);
glBindTexture(GL_TEXTURE_2D, 0);
}
const GLuint shaderTextureBase = kSourceHistoryTextureUnitBase + historyCap + historyCap;
const GLuint shaderTextureBase = layerProgram.shaderTextureBase != 0 ? layerProgram.shaderTextureBase : kSourceHistoryTextureUnitBase;
for (std::size_t index = 0; index < layerProgram.textureBindings.size() + layerProgram.textBindings.size(); ++index)
{
glActiveTexture(GL_TEXTURE0 + shaderTextureBase + static_cast<GLuint>(index));

1
apps/LoopThroughWithOpenGLCompositing/OpenGLComposite.h
View File

@@ -180,6 +180,7 @@ private:
std::string layerId;
std::string shaderId;
GLuint shaderTextureBase = 0;
GLuint program = 0;
GLuint vertexShader = 0;
GLuint fragmentShader = 0;

56
apps/LoopThroughWithOpenGLCompositing/RuntimeHost.cpp
View File

@@ -1571,8 +1571,62 @@ void RuntimeHost::EnsureLayerDefaultsLocked(LayerPersistentState& layerState, co
{
for (const ShaderParameterDefinition& definition : shaderPackage.parameters)
{
if (layerState.parameterValues.find(definition.id) == layerState.parameterValues.end())
auto valueIt = layerState.parameterValues.find(definition.id);
if (valueIt == layerState.parameterValues.end())
{
layerState.parameterValues[definition.id] = DefaultValueForDefinition(definition);
continue;
}
JsonValue valueJson;
bool shouldNormalize = true;
switch (definition.type)
{
case ShaderParameterType::Float:
if (valueIt->second.numberValues.empty())
shouldNormalize = false;
else
valueJson = JsonValue(valueIt->second.numberValues.front());
break;
case ShaderParameterType::Vec2:
case ShaderParameterType::Color:
valueJson = JsonValue::MakeArray();
for (double number : valueIt->second.numberValues)
valueJson.pushBack(JsonValue(number));
break;
case ShaderParameterType::Boolean:
valueJson = JsonValue(valueIt->second.booleanValue);
break;
case ShaderParameterType::Enum:
valueJson = JsonValue(valueIt->second.enumValue);
break;
case ShaderParameterType::Text:
{
const std::string textValue = !valueIt->second.textValue.empty()
? valueIt->second.textValue
: valueIt->second.enumValue;
if (textValue.empty())
{
valueIt->second = DefaultValueForDefinition(definition);
shouldNormalize = false;
}
else
{
valueJson = JsonValue(textValue);
}
break;
}
}
if (!shouldNormalize)
continue;
ShaderParameterValue normalizedValue;
std::string normalizeError;
if (NormalizeAndValidateValue(definition, valueJson, normalizedValue, normalizeError))
valueIt->second = normalizedValue;
else
valueIt->second = DefaultValueForDefinition(definition);
}
}

11
apps/LoopThroughWithOpenGLCompositing/ShaderCompiler.cpp
View File

@@ -100,6 +100,8 @@ std::string BuildTextHelpers(const std::vector<ShaderParameterDefinition>& param
source
<< "float sample" << suffix << "(float2 uv)\n"
<< "{\n"
<< "\tif (uv.x < 0.0 || uv.x > 1.0 || uv.y < 0.0 || uv.y > 1.0)\n"
<< "\t\treturn 0.0;\n"
<< "\treturn " << definition.id << "Texture.Sample(uv).r;\n"
<< "}\n\n"
<< "float4 draw" << suffix << "(float2 uv, float4 fillColor)\n"
@@ -166,13 +168,14 @@ bool ShaderCompiler::BuildWrapperSlangSource(const ShaderPackage& shaderPackage,
return false;
wrapperSource = ReplaceAll(wrapperSource, "{{PARAMETER_UNIFORMS}}", BuildParameterUniforms(shaderPackage.parameters));
wrapperSource = ReplaceAll(wrapperSource, "{{SOURCE_HISTORY_SAMPLERS}}", BuildHistorySamplerDeclarations("gSourceHistory", mMaxTemporalHistoryFrames));
wrapperSource = ReplaceAll(wrapperSource, "{{TEMPORAL_HISTORY_SAMPLERS}}", BuildHistorySamplerDeclarations("gTemporalHistory", mMaxTemporalHistoryFrames));
const unsigned historySamplerCount = shaderPackage.temporal.enabled ? mMaxTemporalHistoryFrames : 0;
wrapperSource = ReplaceAll(wrapperSource, "{{SOURCE_HISTORY_SAMPLERS}}", BuildHistorySamplerDeclarations("gSourceHistory", historySamplerCount));
wrapperSource = ReplaceAll(wrapperSource, "{{TEMPORAL_HISTORY_SAMPLERS}}", BuildHistorySamplerDeclarations("gTemporalHistory", historySamplerCount));
wrapperSource = ReplaceAll(wrapperSource, "{{TEXTURE_SAMPLERS}}", BuildTextureSamplerDeclarations(shaderPackage.textureAssets));
wrapperSource = ReplaceAll(wrapperSource, "{{TEXT_SAMPLERS}}", BuildTextSamplerDeclarations(shaderPackage.parameters));
wrapperSource = ReplaceAll(wrapperSource, "{{TEXT_HELPERS}}", BuildTextHelpers(shaderPackage.parameters));
wrapperSource = ReplaceAll(wrapperSource, "{{SOURCE_HISTORY_SWITCH_CASES}}", BuildHistorySwitchCases("gSourceHistory", mMaxTemporalHistoryFrames));
wrapperSource = ReplaceAll(wrapperSource, "{{TEMPORAL_HISTORY_SWITCH_CASES}}", BuildHistorySwitchCases("gTemporalHistory", mMaxTemporalHistoryFrames));
wrapperSource = ReplaceAll(wrapperSource, "{{SOURCE_HISTORY_SWITCH_CASES}}", BuildHistorySwitchCases("gSourceHistory", historySamplerCount));
wrapperSource = ReplaceAll(wrapperSource, "{{TEMPORAL_HISTORY_SWITCH_CASES}}", BuildHistorySwitchCases("gTemporalHistory", historySamplerCount));
wrapperSource = ReplaceAll(wrapperSource, "{{USER_SHADER_INCLUDE}}", shaderPackage.shaderPath.generic_string());
wrapperSource = ReplaceAll(wrapperSource, "{{ENTRY_POINT_CALL}}", shaderPackage.entryPoint + "(context)");
return true;

BIN
image.png Normal file
View File

Binary file not shown.
Side by Side

After

Width:  |  Height:  |  Size: 48 KiB

9
shaders/text-overlay/shader.slang
View File

@@ -15,11 +15,16 @@ float4 shadeVideo(ShaderContext context)
float2 resolution = max(context.outputResolution, float2(1.0, 1.0));
float aspect = resolution.x / resolution.y;
float2 textSize = float2(0.72 * scale, 0.09 * scale * aspect);
float2 textUv = (context.uv - position) / max(textSize, float2(0.0001, 0.0001));
float2 safeTextSize = max(textSize, float2(0.0001, 0.0001));
float2 textUv = (context.uv - position) / safeTextSize;
bool insideTextRect = textUv.x >= 0.0 && textUv.x <= 1.0 && textUv.y >= 0.0 && textUv.y <= 1.0;
float mask = sampleTitleText(textUv);
float mask = insideTextRect ? sampleTitleText(textUv) : 0.0;
float fill = smoothstep(0.48, 0.54, mask);
float outline = smoothstep(0.48 - outlineWidth, 0.54 - outlineWidth, mask);
float textAlpha = max(fill * fillColor.a, outline * outlineColor.a);
if (textAlpha <= 0.0001)
return context.sourceColor;
float4 base = context.sourceColor;
float4 outlineLayer = float4(outlineColor.rgb * outlineColor.a, outline * outlineColor.a);

1
ui/src/components/ParameterField.jsx
View File

@@ -280,6 +280,7 @@ export function ParameterField({ layer, parameter, onParameterChange }) {
<input
type="text"
maxLength={parameter.maxLength ?? 64}
placeholder={parameter.defaultValue ? `Default: ${parameter.defaultValue}` : ""}
value={draftValue ?? ""}
onFocus={beginInteraction}
onChange={(event) => sendValue(event.target.value)}

21
ui/src/hooks/useThrottledParameterValue.js
View File

@@ -5,33 +5,34 @@ function valuesMatch(left, right) {
}
export function useThrottledParameterValue(parameter, onParameterChange) {
const [draftValue, setDraftValue] = useState(parameter.value);
const [appliedValue, setAppliedValue] = useState(parameter.value);
const currentValue = parameter.value === undefined ? parameter.defaultValue : parameter.value;
const [draftValue, setDraftValue] = useState(currentValue);
const [appliedValue, setAppliedValue] = useState(currentValue);
const pendingTimeoutRef = useRef(null);
const latestDraftRef = useRef(parameter.value);
const latestDraftRef = useRef(currentValue);
const lastSentAtRef = useRef(0);
const isInteractingRef = useRef(false);
const isDirtyRef = useRef(false);
useEffect(() => {
setDraftValue(parameter.value);
setAppliedValue(parameter.value);
latestDraftRef.current = parameter.value;
setDraftValue(currentValue);
setAppliedValue(currentValue);
latestDraftRef.current = currentValue;
lastSentAtRef.current = 0;
isInteractingRef.current = false;
isDirtyRef.current = false;
}, [parameter.id]);
useEffect(() => {
setAppliedValue(parameter.value);
setAppliedValue(currentValue);
latestDraftRef.current = draftValue;
if (isDirtyRef.current && valuesMatch(parameter.value, latestDraftRef.current)) {
if (isDirtyRef.current && valuesMatch(currentValue, latestDraftRef.current)) {
isDirtyRef.current = false;
}
if (!isInteractingRef.current && !isDirtyRef.current) {
setDraftValue(parameter.value);
setDraftValue(currentValue);
}
}, [draftValue, parameter.value]);
}, [draftValue, currentValue]);
useEffect(() => {
return () => {