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Manipulation Tools

In this tutorial, you will learn how to add a zoom manipulation tool.

Preface

In order to render a volume we need:

  • A HTMLDivElement to render the viewport
  • The path to the images (imageIds).

Implementation

We have already stored images on a server for the purpose of this tutorial.

First let's create a HTMLDivElements and style it.

const content = document.getElementById('content');

const element = document.createElement('div');

// Disable the default context menu
element.oncontextmenu = (e) => e.preventDefault();
element.style.width = '500px';
element.style.height = '500px';

content.appendChild(element);

Next, we need a renderingEngine

const renderingEngineId = 'myRenderingEngine';
const renderingEngine = new RenderingEngine(renderingEngineId);

We can use a StackViewport for this example.

const viewportId = 'CT_AXIAL_STACK';

const viewportInput = {
viewportId,
element,
type: ViewportType.STACK,
};

renderingEngine.enableElement(viewportInput);

RenderingEngine will handle creation of the viewports, and we can get the viewport object and set the images on it.

const viewport = renderingEngine.getViewport(viewportId);

viewport.setStack(imageIds);

viewport.render();

In order for us to use manipulation tools, add them inside Cornerstone3DTools internal state via the addTool API.

addTool(ZoomTool);
addTool(WindowLevelTool);

Next, create a ToolGroup and add the tools we want to use. ToolGroups makes it possible to share tools between multiple viewports, so we also need to let the ToolGroup know which viewports it should act on.

const toolGroupId = 'myToolGroup';
const toolGroup = ToolGroupManager.createToolGroup(toolGroupId);

toolGroup.addTool(ZoomTool.toolName);
toolGroup.addTool(WindowLevelTool.toolName);

toolGroup.addViewport(viewportId, renderingEngineId);
Tip

Why do add renderingEngineUID to the ToolGroup? Because viewportId is unique within each renderingEngine.

Next, set the Tool to be active, which means we also need to define a bindings for the tool (which mouse button makes it active).

// Set the windowLevel tool to be active when the mouse left button is pressed
toolGroup.setToolActive(WindowLevelTool.toolName, {
bindings: [
{
mouseButton: csToolsEnums.MouseBindings.Primary, // Left Click
},
],
});

toolGroup.setToolActive(ZoomTool.toolName, {
bindings: [
{
mouseButton: csToolsEnums.MouseBindings.Secondary, // Right Click
},
],
});

Final code

const content = document.getElementById('content');

const element = document.createElement('div');

// Disable the default context menu
element.oncontextmenu = (e) => e.preventDefault();
element.style.width = '500px';
element.style.height = '500px';

content.appendChild(element);

const renderingEngineId = 'myRenderingEngine';
const renderingEngine = new RenderingEngine(renderingEngineId);

const viewportId = 'CT_AXIAL_STACK';

const viewportInput = {
viewportId,
element,
type: ViewportType.STACK,
};

renderingEngine.enableElement(viewportInput);

const viewport = renderingEngine.getViewport(viewportId);

viewport.setStack(imageIds);

viewport.render();

addTool(ZoomTool);
addTool(WindowLevelTool);

const toolGroupId = 'myToolGroup';
const toolGroup = ToolGroupManager.createToolGroup(toolGroupId);

// Add tools to the ToolGroup
toolGroup.addTool(ZoomTool.toolName);
toolGroup.addTool(WindowLevelTool.toolName);

toolGroup.addViewport(viewportId, renderingEngineId);

// Set the windowLevel tool to be active when the mouse left button is pressed
toolGroup.setToolActive(WindowLevelTool.toolName, {
bindings: [
{
mouseButton: csToolsEnums.MouseBindings.Primary, // Left Click
},
],
});

toolGroup.setToolActive(ZoomTool.toolName, {
bindings: [
{
mouseButton: csToolsEnums.MouseBindings.Secondary, // Right Click
},
],
});

You should be able to zoom with right click and window level with left click.

Read more

Learn more about:

For advanced usage of Stack Viewport, please visit Stack API example page.

Tip
  • Visit Examples page to see how to run the examples locally.
  • Check how to debug examples in the Debugging section.