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Image Function_PHP Tutorial
- WBOYOriginal
- 2016-07-20 10:59:40856browse
There is a set of image functions in PHP that can dynamically generate image data streams in gif format and output them to the server. In order for this set of functions to work, the system must have the support of the gd library. If it is under Unix, it should be compiled before compiling PHP Obtain the source code of gd and compile it, generate libgd.a and some .h files, and copy them to the system's library directory and header file directory (such as /usr/lib and /usr/include) respectively; if it is under Windows, PHP3 The .0 installation program will install a gd.dll file. Add 'dl("gd.dll");' to the program to use the image function.
The main image functions are:
(1)ImageCreate(width, height)
Returns an image descriptor.
(2)ImageCreateFromGif(file name);
Returns an image descriptor.
(3)ImageColorAllocate (image descriptor, red, green, blue);
Returns a color descriptor. Since the Gif image can only have 256 colors, it must be assigned a palette first. This statement is to assign a palette item.
(4)ImageColorTransparent(image descriptor, color descriptor);
Specify a color as transparent.
(5)ImageArc (image descriptor, circle center abscissa, circle center ordinate, ellipse width, ellipse height, starting angle, ending angle, color descriptor);
ImageChar(image descriptor, font, x, y, character, color descriptor);
ImageCharUp(image descriptor, font, x, y, character, color descriptor);
ImageCopyResized(target image descriptor, source image descriptor, target x, target y, source x, source y, target width, target height, source width, source height);
ImageDashedLine(image descriptor,x1,y1,x2,y2,color descriptor);
ImageFill(image descriptor, starting point x, starting point y, color descriptor);
ImageFilledPolygon(image descriptor, each vertex array, number of vertices, color descriptor);
ImageFilledRectangle(image descriptor,x1,y1,x2,y2,color descriptor);
ImageFillToBorder(image descriptor, starting point x, starting point y, border color, fill color);
ImageLine(image descriptor,x1,y1,x2,y2,color descriptor);
ImagePolygon(image descriptor, each vertex array, number of vertices, color descriptor);
ImageRectangle(image descriptor,x1,y1,x2,y2,color descriptor);
ImageSetPixel(image descriptor, x, y, color descriptor);
ImageString(image descriptor, font, x, y, string, color descriptor);
ImageStringUp(image descriptor, font, x, y, string, color descriptor);
These are all drawing functions. What needs a brief explanation is that the vertex array of the polygon stores the first point x, the first point y, the second point x, the second point y,...
(6)ImageLoadFont(file name);
The file should be a bitmap font file, and a font number is returned. The system defaults to font numbers 1-5, which can be used directly.