here's a brand new version of vfp paint, a sample that i created using the gdiplusx library that works much like mspaint, and creates a canvas that permits you to draw whatever you want with the mouse.
if you are not aware of what i'm talking about, you might be interested in checking this blog post..
vfppaint now has become much bigger than the original 50k scx from the first version. now it has become a vfp project, and received some important improvements, such as fast and reliable drawing, and the possibility to work with modal forms. many new and cool features were added too.
first of all, thanks for the positive feedback that many readers have sent, and all the suggestions.
requires vfp9 and gdiplusx to run.
please make sure that you have the latest version, because vfppaint uses some functions that were added recently.
when you run vfppaint.scx it will ask you to select the folder where gdiplusx library is located.
what's new on this version:
1 - main screen may be modal, modeless, toplevel or inscreen - this was a problem in the first version. in that case, to obtain scrollbars in my canvas for the case that the image could not fit in the screen, i created a child form, that worked inside the main form. then the child form was configured to show scrollbars when needed. but working with this configuration, the main form had to be a toplevel form, and it was not possible to make that form modal.
thanks to carlos alloatti and malcolm greene for their great "scrollablecontainer", i was able to use just a single control, and concentrate just on the drawing codes, i confess that it was a little bit complicated to control the form scrollbars and the image position in the original way. now this is all done by the scrollable container. thnaks very much carlos for your support to make it work as i desired. anyway, some tweaks were needed to be aplied in this control to make it behave exactly as i needed, and i created my customized version. check the file scontainertweaks.txt in the "source" folder.
2 - faster image drawing - i confess that the original version worked really sloooooow when direct drawing on the canvas. that's because vfp and gdiplusx has to work a lot in order to draw the image. after detecting the mouse position, cloning the original image for undo purposes, i used gdiplusx to obtain the pictureval of the bitmap, and then the image pictureval property was updated. obtaining the pictureval was the slowest operation. in this new version, i'm using gdi+ to draw du]irectly on the screen, using the hwnd of the form, when the left button of the mouse is pressed. only when the user releases the button or when he leaves the canvas surface is that the pictureval of the image object is updated, check it by yourself, this brought a huge performance gain !
3 - cut, copy and paste - these possibilities were added too. now you can select any portion of the image, cut or copy to the clipboard, and paste in any other application, or even inside vfppaint, moving pieces of images inside the canvas. it supports also that you paste any image from the clipboard. you can capture any screen using the prtscrn key and paste it there.
4 - drag and drop pieces of images. this brings the possibility to apply some effects in the whole image or just in the specified region.
5 - special color effects - there were lots of other cool things that i wanted to add, but no more space was available in the original form, so i've created a child form that agrupates some slidebars that will control the image colors, like: contrast, saturation, brightness, gamma, hue and adjusting each of the basic colors individually.
6 - other color effects - with just one click obtain monochrome, greyscale and invert the colors (negative)
7 - image transformations - another child form permits you to rotate the image by a desired angle, scale and shear vertically or horizontally.
8 - other tweaks, small fixes and optimizations. all methods were revised in order to enhance the performance and reliability.
- draw points, rectangles lines and ellipses with the mouse.
- text drawing, choose any font, size and style, and it will appear at the place that you click on the image. (drag and drop to choose the best place)
- choose any color, from the palette or directly from the loaded image or canvas and select the pen width that you want to draw.
- select the shape or type of drawing in the graphical option buttons, and then go to the canvas (image object) and click the left mouse button.
- drag and drop is available for rectangles, lines and ellipses.
- basic undo features
- rotate and flip images
- resizing images
- printing and saving images
- scale, shear and rotate images
- apply image effects, like greyscale, saturation, contrast, brightness, and more
|load image to canvas|
|save image in desired image format|
|undo last changes|
|pick color from palette|
|clear entire canvas with selected color|
|rotate left (whole or selected image)|
|rotate right (whole or selected image)|
|flip image horizontally (whole or selected image)|
|flip image vertically (whole or selected image)|
|select a piece of the image, to be cut, copied, dropped or receive an effect|
|pick color from canvas|
|select font, size and type|
|convert to greyscale|
|convert to monochrome|
|convert to negative|
|calls child form that enables different kinds of resizing|
calls child form that allows scaling, shearing and rotating the image
|calls child form that allows several color effects to the image|
|send the selected piece of image to the clipboard|
|copy the selected piece of image to the clipboard|
|paste image from the clipboard to the canvas|
|paste special, allowing to choose the destination of the image|
all images are generated without disk access, using the new pictureval property of the image control. for this specific case, i didn't use the imagecanvas that ships with gdiplusx because i needed some extra customization. after the latest release of gdiplusx, getting the pictureval property of an image has became very simplified, with the new methods added to the image class - getpictureval and getpicturevalfromhbitmap.
as sometimes we need to work with an image that is bigger than our screen, the drawing canvas was put in a "in toplevelform" that has scrollbars.
another cool feature is the "undo" possibilities. vfppaint stores the previous bitmap in a cache. this can be improved too, maybe you need to "undo" in higher level. for this, very few code is needed.
when drawing on the canvas, try dragging and dropping the objects. for this, the "undo" feature was highly used, because the shape is drawn, and when the user moves the mouse, it restores the original image from the buffer and draws again in the new position.
when a big sized image is loaded, first it asks if the canvas needs to be resized.
scrollbars appear in the image to help dealing with it. in a first moment, i thought of using the very nice ctl32 scrollable container from carlos aloatti and malcolm greene, but i gave up because i needed the pictureval property, that is present only in the default image control. so, there are currently 2 forms in the screenshot below. one is a "in toplevel" form that contains just one image object, and resides in the main vfppaint form. the other form is a "toplevel form". the image object from the "child form" changes its size automatically, depending on the image dimensions. when this object is resized, the child form automatically resizes itself, and shows and adjusts the scrollbars if needed.
vfppaint also accepts that you pass an image file as a parameter. this way, you'll be able to open the form loading automatically the desired image to edit. run the form like this:
do form vfppaint with "eyes.gif"
in case you pass a gif image as a parameter, it will be automatically converted to 24bpp. that's because gifs are indexed images. a classic example of indexed images are monochrome. pure monochrome images use only 1 bit per pixel. so, in just one byte you can store information of 8 pixels ! in the case of gifs, they are usually 8 bits per pixel, so in one bit we can have a value that ranges from 0 to 255 - that's exactly the quantity of colors supported by gifs ! unfortunately, the redistributable version of gdi+ has a limitation when working with images created in indexed pixel formats, such as 1bppindexed (0x00030101), 4bppindexed (0x00030402) and 8bppindexed (0x00030803). if you try to draw on this kind of images you'll always receive an error message when you'll create the graphics object, that permits to you to draw on the image. more detailed info about this can be found in this post: drawing on gifs or indexed pixel format images with gdi+ http://weblogs.foxite.com/vfpimaging/archive/2006/03/18/1302.aspx . that's why gifs are converted to a 24bpp format before initializing the painting possibilities.
but the main thing is that this totally customizable. the more important in this form is the technique that was used, and you'll see that there's not too much code there.
for the next version:
bhavbuti nathmani, from india suggests me to add multiple undo possibilities and the possibility to zoom the images. that's not too much complicated, maybe i'll get some time and these could be added. as i added many new features, it is possible that some bugs may appear. if you find something wrong, or have any suggestion, please tell me !