This tutorial demonstrates how to create images from scratch using PHP's GD library. We'll cover drawing basic shapes, controlling line attributes, adding text, and creating simple designs. Here's a preview of the final result:
Key Concepts:
- Drawing basic shapes with PHP's GD functions.
- Customizing line thickness, style, and fill colors.
- Rendering text onto images using TrueType fonts.
- Creating simple designs and graphical elements.
Drawing Basic Shapes
This section focuses on fundamental shapes. Line thickness, brushes, and styles will be covered later.
Drawing Lines
The imagettfbbox() function determines the bounding box of text rendered with TrueType fonts. This is useful for scaling text to fit within image dimensions. imagettftext() then draws the text onto the image.
The following code snippet, inserted before the image save operation, adds concentric filled circles to the corners:
$edge_distance = 20;
$largest_size = 200;
$size_drop = 10;
$central_point = $largest_size/2 + $edge_distance;
for($i = 0; $i < 20; $i++){
$ellipse_size = $largest_size - $size_drop*$i;
$ellipse_color = $white;
if($i%2 != 0){
$ellipse_color = $blue;
}
imagefilledellipse($img, $central_point, $img_height, $ellipse_size, $ellipse_size, $ellipse_color);
imagefilledellipse($img, $img_width - $central_point, 0, $ellipse_size, $ellipse_size, $ellipse_color);
}
As demonstrated, simple mathematical calculations combined with PHP's GD functions allow for the creation of complex patterns.
Conclusion
This tutorial introduced several GD functions for drawing basic shapes in PHP. With some mathematical manipulation, these functions can be used to create more intricate shapes (e.g., regular polygons, rounded rectangles). PHP's GD library also provides robust text rendering capabilities, ensuring clean text integration into images. Share your creative text effects in the comments!
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