What gradients are there in canvas?

The gradients in canvas include linear gradients and radial gradients. Detailed introduction: 1. Linear gradient defines the direction and range of the gradient through the line segment between two points. You can use the "Canvas' createLinearGradient()" method to create a linear gradient object and use the "addColorStop()" method to set it. The color and position of the gradient; 2. Radial gradient defines the shape and range of the gradient through a center point and a radius, etc.

# Operating system for this tutorial: Windows 10 system, Dell G3 computer.

In Canvas, we can use gradients to create richer and more diverse graphic effects. Gradient can be applied to fills and strokes to add color transitions to graphic elements. There are two main types of gradients in Canvas: linear gradients and radial gradients.

Linear Gradient:

Linear gradient defines the direction and range of the gradient through the line segment between two points. We can use the createLinearGradient() method of Canvas to create a linear gradient object, and use the addColorStop() method to set the color and position of the gradient.

For example, the following code creates a linear gradient from the upper left corner to the lower right corner, with the color gradient from red to blue:

var canvas = document.getElementById('myCanvas');
var ctx = canvas.getContext('2d');
// 创建线性渐变对象
var gradient = ctx.createLinearGradient(0, 0, canvas.width, canvas.height);
// 设置渐变颜色
gradient.addColorStop(0, 'red');
gradient.addColorStop(1, 'blue');
// 使用渐变作为填充
ctx.fillStyle = gradient;
ctx.fillRect(0, 0, canvas.width, canvas.height);

Radial Gradient:

Radial gradients define the shape and range of the gradient through a center point and a radius. We can use the createRadialGradient() method of Canvas to create a radial gradient object, and use the addColorStop() method to set the color and position of the gradient.

For example, the following code creates a radial gradient from inner red to outer blue:

var canvas = document.getElementById('myCanvas');
var ctx = canvas.getContext('2d');
// 创建径向渐变对象
var gradient = ctx.createRadialGradient(canvas.width/2, canvas.height/2, 0, canvas.width/2, canvas.height/2, canvas.width/2);
// 设置渐变颜色
gradient.addColorStop(0, 'red');
gradient.addColorStop(1, 'blue');
// 使用渐变作为填充
ctx.fillStyle = gradient;
ctx.fillRect(0, 0, canvas.width, canvas.height);

In addition to the basic linear and radial gradients described above, Canvas also supports more complex gradient forms , such as repeating gradients and transparency settings for color stops. It can be adjusted and combined according to specific needs to create more diverse gradient effects.

To summarize, linear gradients and radial gradients can be used in Canvas to add color transition effects to graphic elements. A linear gradient uses a line segment between two points to define the direction and range of the gradient, while a radial gradient uses a center point and a radius to define the shape and range of the gradient. By setting different colors and positions, you can create rich and diverse gradient effects, thereby enhancing the visual appeal of your graphics.

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