2,625 questions
625
votes
42
answers
470k
views
How can I determine whether a 2D Point is within a Polygon?
I'm trying to create a fast 2D point inside polygon algorithm, for use in hit-testing (e.g. Polygon.contains(p:Point)). Suggestions for effective techniques would be appreciated.
- 40k
0
votes
1
answer
7k
views
Display an array of color in C [closed]
My program both writes and reads arrays of colors like this one:
struct Image {
size_t width;
size_t height;
struct Color *data;
}
struct Color {
char r;
char g;
char b;
}
...
- 3,045
20
votes
3
answers
40k
views
Draw a line in a JPanel with button click in Java
I want to draw a line in a JPanel.
This is my GUI and I want a line in the JPanel in white.
I find many examples but the problem is the how to use it.
In many exmples, always they draw in a JFrame ...
- 11.9k
280
votes
15
answers
211k
views
Ball to Ball Collision - Detection and Handling
With the help of the Stack Overflow community I've written a pretty basic-but fun physics simulator.
You click and drag the mouse to launch a ball. It will bounce around and eventually stop on the &...
163
votes
4
answers
196k
views
How to use Greek symbols in ggplot2?
My categories need to be named with Greek letters. I am using ggplot2, and it works beautifully with the data. Unfortunately I cannot figure out how to put those greek symbols on the x axis (at the ...
- 8,202
49
votes
7
answers
65k
views
Fast work with Bitmaps in C#
I need to access each pixel of a Bitmap, work with them, then save them to a Bitmap.
Using Bitmap.GetPixel() and Bitmap.SetPixel(), my program runs slowly.
How can I quickly convert Bitmap to byte[] ...
- 19.1k
5
votes
1
answer
2k
views
Translucent circular Control with text
I am working on a project wherein I need to add a Control with the shape of a Circle with some text in the middle.
My problem is the circle is too small, when I resize it, it overlaps other controls. ...
- 447
328
votes
13
answers
1.1m
views
How do I position one image on top of another in HTML?
I'm a beginner at rails programming, attempting to show many images on a page. Some images are to lay on top of others. To make it simple, say I want a blue square, with a red square in the upper ...
- 9,461
8
votes
4
answers
24k
views
Java, how to draw constantly changing graphics
Have not done this before, so obviously I suck at it. Here 64 pixels around current mouse position get drawn little bigger on a form. Problem is, that it's 'kind of' to slow, and I have no idea where ...
- 20.1k
15
votes
3
answers
14k
views
OpenGL - How to create Order Independent transparency?
I've been working on a game engine for educational purposes and I came across this issue I cannot seem to find an answer for:
Alpha channel only works for objects that have already been drawn before ...
- 185
398
votes
26
answers
308k
views
Creating a blurring overlay view
In the Music app of the new iOS, we can see an album cover behind a view that blurs it.
How can something like that be accomplished? I've read the documentation, but did not find anything there.
- 3,569
192
votes
13
answers
504k
views
How to read the RGB value of a given pixel in Python?
If I open an image with open("image.jpg"), how can I get the RGB values of a pixel assuming I have the coordinates of the pixel?
Then, how can I do the reverse of this? Starting with a blank graphic, ...
- 14.5k
124
votes
8
answers
280k
views
How can I set the matplotlib 'backend'?
I am new user of matplotlib, my platform is Ubuntu 10.04 Python 2.6.5
This is my code
import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
plt.plot([1,2,3])
The error is:
/usr/...
- 9,559
71
votes
10
answers
564k
views
11
votes
2
answers
13k
views
Ray Casting with different height size
I have a java project who makes the "windows' maze" and use the ray casting algorithm. Here's a screenshot :
Like you can see all the walls have the same height size. I would like to do the same but ...
- 415