imagefilledrectangle()

(PHP 4, PHP 5, PHP 7)

画一矩形并填充

说明

imagefilledrectangle()在$image图像中画一个用$color颜色填充了的矩形，其左上角坐标为$x1，$y1，右下角坐标为$x2，$y2。0, 0 是图像的最左上角。

If you want to draw a rectangle with rounded corners, you can use this simple function... 
Rectangle starts at x1y1 and ends at x2y2. $radius defines radius of circled corner. 

I've made a function to make full color gradients:

More functions at http://www.sphoera.com

I wanted to clear an image, and set it to full transparent.
imagefilledrectangle() seems to ignore alpha channel and alpha blending.
Use imagefill() instead: 

a simple way of using imagerectangle to create a percentage bar 

I would like to inform developers about a problem I encountered when trying to use imagefilledrectangle.
I noted that the order in which the start and end y coordinates are listed is extremely important.
as in the statements below.
if($this->d_values[$i]['unit_value'] img,$position_x, $start_y , $end_x, $end_y ,$d_color);      
else        
imagefilledrectangle($this->img, $position_x,$ end_y , $end_x, $start_y,$d_colour);      
      
Thanks

Important quirk to note:
While imagerectangle will allow you to use a different order of your coordinates (such as bottom-left to upper-right), imagefilledrectangle will only work correctly if you use top-left to bottom-right as indicated in the docs.

The issue with filling using a rectangle is caused in your code by having alpha blending turned on before rendering the filled rectangle. Alpha blending causes what you draw on the image to be blended with whatever is already on the image according to the alpha channels of each. Therefore, because blending is on, and because the rectangle's fill colour is completely transparent, the blending of the existing image content with the transparent rectangle results in no change to the existing image.
With blending off, when drawing to the image what you draw completely replaces what is already there. So, drawing the rectangle in this case results in the original content of the image being completely replaced with a transparent rectangle.
So in order to use imagefilledrectangle() to erase an image to transparency, you need to turn off alpha blending first.
I guess the reason imagefill() works with alpha blending on is because it does not perform any alpha blending - it always works without alpha blending regardless of the setting. I suspect there are reasons for this to do with alpha channels complicating edge detection.
I would recommend using imagefilledrectangle() to create a blank transparent image resource instead of imagefill() because it is undoubtedly much faster in probably all cases.
Here is some example code to blank an image to transparent, assuming $im is a successfully created image: 

The examples in function imagettfbbox() gave me many problems because of misunderstand of how the text is positionned in the box.
So I did a new example:
- writing a text
- in the correct position in its box
- with a padding around
Enjoy !
Mike 

It looks like there are waves beetween the points, but it's straight. 

Thanks terereese. it took me over two hours to figure that one out.
it worked locally: imagefilledrectangle(imagresource, int x1, int x2, int y1, inty2, color)
BUT remote on my provider only this worked: imagefilledrectangle(imagresource, int x1, int y2, int x1, inty1, color)
Any ideas why and where?

As of PHP 5, it seems to be no longer necessary to draw the rectangle from the upper left to the lower right corner. This led me into big trouble porting a script developed under PHP 5 to PHP 4.

That script draws Serpinski's carpet: 

As stated above, it needs to go from the top left corner to the bottom right corner. Just use this to flip it if neccessary:
// flip them if neccessary (x3, y3 are temp vars)
if($x1 > $x2) { $x3 = $x2; $x2 = $x1; $x1 = $x3; }
if($y1 > $y2) { $y3 = $y2; $y2 = $y1; $y1 = $y3; }
ImageFilledRectangle($im, $x1, $y1, $x2, $y2, $color);

鹏仔微信 15129739599 鹏仔QQ344225443 鹏仔前端 pjxi.com 共享博客 sharedbk.com