I want to load a specific part of an image in pygame.
How do I do it?
I have an image of a character in different angles. In SDL we use a rect, but do we have this option in pygame?
https://www.pygame.org/docs/ref/surface.html#pygame.Surface.blit
use the surface.blit(source, dest, area=None, special_flags = 0)). the area argument will allow you to put a rect of what part of the image that you want to draw
Related
I have used opencv to read png files (with no background) and convert them into pygame surface. Here are the two examples of how I did it:
Method 1:
character=pygame.image.load("character.png")
Method 2:
CharacterImage=cv2.imread("character.png")
CharacterImage=convertToRGB(CharacterImage,CharSize,CharSize)
#charSize is desired character size (for example: 50)
#I have created a user defined function as pygame renders in RGB whereas cv2 renders in BGR image format.
CharacterActions.append(rotate(pygame.surfarray.make_surface(CharacterImage),charrot))
#charrot is rotation angle
I understand that I could manually resize images and then use the first method to get the transparent background image. But I want to understand if its possible to obtain the same via second method? I don't want to manually edit so many images resizing them and that's why I want to know if there's a way for the same.
Thanks in Advance
On the images you load using your Method 1 (pygame.image.load()), you should use pygame.transform.scale() and pygame.transform.rotate() to manipulate the loaded image.
To maintain the transparency, you need to keep the alpa of the image you are loading. To do that you need to use .convert_alpha() on the resulting image. You can do that after or before the transform.
For each of these commands I have linked them to the documentation, just click on them so you can read it.
Is it possible to get the color (rgb-value and transparency) of a point (x/y-coordinate) from the canvas? Example: I draw some figures and text on a canvas and later I want to get the color of a point at a specific coordinate.
The solution should be independent whether the canvas is visible on screen or not. And it should work independently from the operating system.
I didn't found any solution on the web. That's why I assume that this is not possible. Am I right?
The canvas isn't very pixel-based, and provides no API for doing this.
But if you've got the tkimg package installed, you can use that to do a screengrab of the canvas and then fetch the pixel value out of that.
package require Img
# Get the data into an image
set screengrab [image create photo -format window -data $theCanvas]
# Read the pixel data out of the grabbed image
set pixeldata [$screengrab get $x $y]
# Get rid of the grabbed data once you're done
image delete $screengrab
Note that the coordinates concerned will be viewport coordinates, not canvas internal coordinates: if you've scrolled the canvas, you'll have to offset as necessary.
You are correct, tk does not provide any way to get the color of a specific pixel on a canvas.
I am working on flash professional cs5.5 and actionscript 3. I need to use symbols of customized sizes to test the hitTestOjbect() function. However, when i convert the bitmap to a symbol, by default it goes into a rectangular size and the empty space all around is also detected as part of the symbol.
Is there any way to keep the size of the symbol customized ?
That is the nature of a bitmap. Technically, bitmaps are always rectangular. Transparent areas are just fills with alpha-0. When you convert a bitmap to a symbol, the bitmap still exists, just inside the context of the symbol.
One of the fastest ways to fix this is to use a mask inside your MovieClip. Create a plain drawing object in the exact shape of the hit area you want. Then, place that on your timeline on it's own layer. Right-click the layer with the mask, click "Mask", and then drag the bitmap's layer under the mask one. Lock both layers, and exit symbol editing.
Now your hit area will be limited to only the masked area.
EDIT: I appear to be mistaken - hitTestArea is always rectangular. See the top answer to hitTestObject Collision Not Registering Correctly.
does anybody know/have some idea how to make a mask follow a line? Basically I have a drawing made with 1px line and I need to gradually mask this shape so it actually looks like it is being drawn. The thing is that I cannot just increase the width of the mask (it would simple draw a vertical line in one step which is not desired), it has to be a linear movement along the "guide" line, so the vertical line gets drawn in several steps. Doing this manually will/would be a major pain. This is what I am trying to achieve:
Thanks a lot!
You have to do it manually. Though there are some shortcuts you can take:
Create a Guide layer in Flash Pro.
Copy a vector of your path to this guide layer.
Create a new layer below it, put a circle on that layer at the start of the path and make a classic tween of that circle.
Dock your circle layer under your guide layer and at the last frame of your tween move the circle to the end of the path. This will make the circle go along the path.
Follow the animation and manually fill the covered parts.
Put your guide, circle animation and following animation into a MovieClip and put it above your to be masked symbol and make its layer a mask.
Here's an example I made for you if I wasn't clear enough: http://db.tt/kvaaYaLA
Note that this method is only useful if you need a static animation, not for a dynamic one.
I tried to draw on the image using canvas. Yes, of-course i did. But i need to merge the canvas drawing with the image instantly.
i.e My concept is, i have one image (#a) and i like to mark some places on the image (circle, rectangle, etc...), so i have just pick the canvas technique. (if any other technique is available please suggest me.)
So, after the canvas drawing, i want to merge the canvas image with my actual image (#a). Then, i'll get the marked image.
What i did before?.
I was set the background as my actual image(#a) to the canvas tag. (i.e canvas tag with some background image). I have done the drawing. Then, i have convert the canvas image as dataURI, then i will merge the actual image (#a) with canvas drawing using Linux command (imageMagic).
Can you tell me any other way, to draw directly on the image and save the drawing with image instantly.?
Thanks in advance.
Don't set the background of the canvas.
Instead, you want to use the drawImage() function of the canvas context to literally paint the image onto the canvas. Then do all your drawing operations.
Then you can save the image correctly. I'd also suggest looking in to Canvas2Image for that.
http://www.nihilogic.dk/labs/canvas2image/