drawing

问题 I am confused what's the different between System.Drawing.Image and System.Drawing.Bitmap Can someone explain the major difference between those two types ? And Why to use System.Drawing.Bitmap instead of System.Drawing.Image ? 回答1: Bitmap inherits from Image : System.Drawing.Bitmap : System.Drawing.Image { } Image is an abstract class, this means: The abstract modifier indicates that the thing being modified has a missing or incomplete implementation. Bitmap is a sealed class, this means:

问题 I am confused what's the different between System.Drawing.Image and System.Drawing.Bitmap Can someone explain the major difference between those two types ? And Why to use System.Drawing.Bitmap instead of System.Drawing.Image ? 回答1: Bitmap inherits from Image : System.Drawing.Bitmap : System.Drawing.Image { } Image is an abstract class, this means: The abstract modifier indicates that the thing being modified has a missing or incomplete implementation. Bitmap is a sealed class, this means:

问题 i' working with Gtk developing some app. I must put some buttons over a map. I'm drawing the map on a GtkDrawingarea, but i'm not able to put buttons over it. Any suggestion? Thanks 回答1: Suggestions: Put both the drawing area and the buttons inside a GtkFixed container. Probably not the best solution, because GtkFixed has no way of controlling the z-ordering (other than the order in which you add the widgets to it?) Instead of using GtkDrawingArea , use a canvas widget that can include other

问题 For testing purposes let's assume I've draw 2 teapots with glutSolidTeapot() , like this: glColor3f(1.0f, 0.0f, 0.0f); // Red teapot glutWireTeapot(1.0f); glColor3f(0.0f, 1.0f, 0.0f); // Green teapot glTranslatef(0.0f, 0.0f, 3.0f); glutWireTeapot(1.0f); The camera is initially located at (x,y,z) = (0.0f, 0.0f, 5.0f) and I'm looking at z = -1 (this is camera position #1). I'm sure you understand that the green teapot is the closest object to the camera and the red one is behind it. The problem

问题 I want to write pixels directly to to screen (not using vertices and polygons). I have investigated a variety of answers to similar questions, the most notable ones here and here. I see a couple ways drawing pixels to the screen might be possible, but they both seem to be indirect and use unnecessary floating point operations: Draw a GL_POINT for each pixel on the screen. I've tried this and it works, but this seems like an inefficient way to draw pixels onto the screen. Why write my data in

问题 I am writing a GLPaint-esque drawing application for the iPad, however I have hit a stumbling block. Specifically, I am trying to implement two things at the moment: 1) A background image that can be drawn onto. 2) The ability to draw temporary shapes, e.g. you might draw a line, but the final shape would only be committed once the finger has lifted. For the background image, I understand the idea is to draw the image into a VBO and draw it right before every line drawing. This is fine, but

问题 I'm writing an implementation of Conway's Game of Life in C#. This is the code I'm using to draw the grid, it's in my panel_Paint event. g is the graphics context. for (int y = 0; y < numOfCells * cellSize; y += cellSize) { for (int x = 0; x < numOfCells * cellSize; x += cellSize) { g.DrawLine(p, x, 0, x, y + numOfCells * cellSize); g.DrawLine(p, 0, x, y + size * drawnGrid, x); } } When I run my program, it is unresponsive until it finishes drawing the grid, which takes a few seconds at

问题 I have a list of points. For example, points = [[160, 75], [115, 567]] . How to draw a line in PyQt4, so it would be something like this: Thanks in advance. EDIT: For the record, I'm trying to implement Bezier Curves, so it looked like this: Here is the code I have at the moment: from PyQt4.QtGui import QWidget, QPolygonF, QPainter, QPen, QBrush, QColor, \ QApplication, QIcon, QVBoxLayout, QSlider, QHBoxLayout, QPushButton, QLCDNumber from PyQt4.QtCore import QObject, SIGNAL, SLOT, QPointF,

问题 I want to create a "fill" that fills the inside of a polygon, created using a point list, but be able to remove its holes. My old code: Private Sub DrawSomething(ByVal points as List(of Point), _ ByVal myBrush As System.Drawing.Brush, _ ByVal myGraphics As System.Drawing.Graphics) myGraphics.FillPolygon(myBrush, points) End Sub It simply fills a polygon created by the contour of the points in the list. How can I fill the polygon, but exclude the holes in it (which I know are inside, I have

问题 How do I create an in-memory fully transparent SWT image and draw a black line on it with antialias enabled? I expect the result to include only black color and alpha values ranging from 0 to 255 due to antialias... I googled and tried everything that I could... is this possible at all? 回答1: This is how I did and it works: Image src = new Image(null, 16, 16); ImageData imageData = src.getImageData(); imageData.transparentPixel = imageData.getPixel(0, 0); src.dispose(); Image icon = new Image