Visual C++ :: How To Draw Pixel-level Color Gradients In CScrollView
Oct 6, 2012
i wish to plot a mathematical function on a 2-dimensional grid. The function will be represented by 3 sets of floats, x-values, y-values, and z-values. Obviously, it is impossible to plot 3 such data sets on a 2D grid, so one approach is to use pixel coloration to represent the z-values.
Those examples (and there are many to be found) show something like the function of the complex variable z, f(z) = exp(z). I have attached a exp(z).jpg example of the imaginary part of the plot exp(z).
My question is: How to accomplish such a gradient colorization, assuming one already has the data?
I have experimented with Gdiplus SetPixel, but I have not figured out how to produce a smooth gradient.
Im new to c#. In c++ I have made a window and painted it with dots and concentric circles, like a radar PPI screen. Trying to do this in c#, I can't find how to draw a single pixel on the window.
Also, what should I be drawing on: the form, panel, picturebox...?
I dont even know where to start. I spend the last 7h infront of my computer and i'm so frustrated cause my professor gave us no information what so ever. At the moment its more of a trial and error process than anything else.
How would i set the color of an individual pixel for examplel or how would i save the file ?
I'm trying to blur a ppm image by averaging the components of the color(r, g, b) within a certain reach of a specific pixel. This is a picture and description:
In this diagram, we are trying to compute the color for the pixel in the center (the red element). Its neighbors (within a reach of 4) are all of the green elements. The pixels outside of this 9x9 square are not considered in the blurring calculation for this pixel. To compute the color for the center pixel, average the red, green, and blue components (independently) of every pixel in the 9x9 square (including the pixel itself; the red element in this diagram).
I have some code, but it is not working correctly. The function "computed_color" on line 52 is shown in the next block of code.
I am writing an software that should be able to detect all keyboard inputs by the user. i.e., both hardware and software/on-screen keyboard.
This software is going to be written in a platform independent way and supposed to run on Windows, Linux, Android & iOS.
The idea is to capture the keyboard inputs from a low level, there by making sure that it doesn't miss any inputs even if it's a on-screen keyboard like in a mobile device.
I am looking at possible open source libraries that can be used.
The first dimension of this vector is the angle of the data so there are 360 angles, and the second dimension is the bins of the data in which there are 512 bins per angle. Each bin has a value from 0 to 15 to determine the intensity of the bin. So basically, when this is all display, there will be a circle of data, with varying colors of intensity at each bin.
What is the best approach to doing this in MFC? How to draw this on the screen?
I have a CScrollView that displays a bitmap and I'm trying to draw a grid that I can turn off and on by check box and when the mouse is over a section of the grid that square highlights... I do all the drawing in the ondraw function... But when I have many grid squares it becomes slow to scroll and to highlight the square the mouse is over... I'm not sure the best way to go about this and where to place code to speed it up... The bitmap is only loaded once... But in ondraw the grid has to redraw every time scrolled and when mouse moved over a square.. In onmousemove I call invalidate so the square under mouse changes...
I am writing a pure C based win32 applications. I have drawn line. Now i want to translate that line, move the line whereved user wants to move on screen. Then again I drawn another line, I am drawing multiple lines.
I have created rectangle region for each line and trying to move the line.
When I move the 2nd line over the 1st line on screen the 1st line is getting wiped out. Because I am InvalidateRect() of the rect for the line being moved, so when that rectangle is crossing the other line then the other line is getting removed from the screen.
How can I rectify it. How can I have all the lined being on the screen and moved according to the user's wish. The code should be pure C and win32 no MFC.
I am trying to make this code working and to remake it to work also for RGB to HSB? This code is for C and I need to make it working in Visual Studio C++ .
Code: // mask1.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include <stdio.h> #include <math.h> typedef struct RGB_t { unsigned char red, green, blue; } RGB; typedef struct HSB_t { float hue, saturation, brightness; } HSB;
[code]....
Error I got is error C3861: 'fmaxf': identifier not found
What file or namespace should I include. Do I need to add some library into linker?
When I remove the BeginPath() and EndPath() functions my lines are being drawn. But when I insert this BeginPath() and EndPath() and StrokeAndFillPath(hDC); the nothing is being drawn.
Why it is not doing as per the expectations. I want to draw a shape for example A with a outline. And i want it to be closed when drawing is ended and filled the hollow portion.
What am I doing wrong in this ?I am not implementing it in WM_PAINT but drawing is done in WM_LBUTTONUP.
Trying to define some global colors so I can use the one instance though-out my application. Here is my color code:
<Color x:Key="GlobalTextColor">#E0E0E0</Color>
But this color doesn't display in the list when I start to type {StaticResource ...}
This is the code where I'm trying to reference the color, see Stroke="{StaticResource GlobalTextColor}". GlobalTextColor doesn't actually come up in the list so won't work.
I know how to change the back color of text in th ListView for all the View, but if I only want to change the back color of one cell i don`t find any way. Is it possible?
I m trying to place an image on the colour frame of the Kinect live video. I m able to overlay the image using alpha blending mechanism.
The image used is a bitmap image of dimension 128*128.
The Kinect has a resolution of 640*480.
IDE used is Visual studio 2010 and I m developing using c++.
The Kinect has a render target whose size is taken as 640*480 so that it stretches for the complete window. So when I try to overlay the image it appears 5 times because of this stretching. If I increase the image size to 640*128 i get a single image that is stretched horizontally across the window with dimension 640*480.
I have created a function that will create a render target with bitmap properties and size equal to 640*480. This is used to store the data from the Kinect, frame by frame, and draw it on to the screen
So I think when I overlay the image, it gets replicated 5 times to meet the render target size.By default the image is placed at the left top position.
My doubts are
- How can I use different functions to specify the size of render target for Kinect as 640*480 and the size of render target for bitmap image as 128*128.
- How to I give overlay or place the image on the live video at a specific location.
I used onctlcolor() method to set the background color for the controls & Dialog. I run my application, working good but after 15 mins the below error occured,
Application Error:
The Required Resource Was --------> Shown message box
Program Error:
First-chance exception at 0x7c81eb33 in XRay.exe: Microsoft C++ exception: CResourceException @ 0x001274f8. First-chance exception at 0x7c81eb33 in XRay.exe: Microsoft C++ exception: CResourceException @ 0x001259d0. First-chance exception at 0x7c81eb33 in XRay.exe: Microsoft C++ exception: CResourceException @ 0x00123ea8. First-chance exception at 0x7c81eb33 in XRay.exe: Microsoft C++ exception: CResourceException @ 0x00122380. First-chance exception at 0x7c81eb33 in XRay.exe: Microsoft C++ exception: CResourceException @ 0x00120858. Warning: Uncaught exception in WindowProc (returning 0).
what is the reason for that? How can i prevent my project from this problem.
I needed to change Default Text attributes (font and color) . So I wrote following code , UnicodeTextOut function. I called this function once in each 55ms to update the display screen. but I observed that my Screen used to become grey like a crash after sometime . If I use Minimize an Maximize window , the screen was restoring back for some time.
When I thought over the code , I got my mistake that CreateFont initialization should be done once in the program and probably outside the function.
Then I shifted the line hFontUnicode = CreateFont(16, 0, 0, 0, 0 , 0, 0, 0, 0, 0, 0, 0, 0, _T("Aerial")); in my screen class constructor and made hFontUnicode global .
This solved my problem as expected. Why a system crash after certain no of CreateFont calls ?
How to configurate color of selected text. I am not sure why, but in Visual C++ it is not displayed as in other programs like notepad, which should be harder color. So I cannot find the selected text. Where can I configurate it or where to search it in desktop theme settings?
I installed FLTK 1.3.X from [URL] on my visual studio 2012 compiler and use PPP book for C++ programming [URL]. My problem is about filling a Shape in.
Code: #include <Simple_window.h> using namespace Graph_lib; int main() { Simple_window win(Point(100,100), 1000, 600, "Binary_tree"); Graph_lib::Circle c(Point(200,200),50); c.set_color(Color::red);
[code]....
When I run the program, All three Shapes are drawn on window but only the Rectangle is filled in! Why? set_color works for the three and apparently the set_fill_color is defined for all Shapes and it too should work but why it doesn't for Circle and Ellipse?
I want to track the mouse movement. I know that GTk+ provides some powerful libraries for creating GUI, that will, among other things, enable me to write handlers for mouse movement events, but I'm looking for a simpler, more compact capabilities for now.
Is there a low level C library that will enable me to interface with the mouse?
