2d

Where would i go to look for algorithms that take a 2d grid of values that are either 0 or 1 as input and then identifies all possible non-overlapping rectangles in it? In a more practical explanation: I am drawing a grid that is represented by a number of squares, and i wish to find a way to combine as many adjacent squares into rectangles as possible, in order to cut down on the time spent on cycling through each square and drawing it. Maximum efficiency is not needed, speed is more important. Addendum: Apparently what i am looking for seems to be a technique called Tesselation. Now i only

My application should be able to copy 32-bit images (RGB + alpha channel) to the clipboard and paste these images from the clipboard. For this I plan to use CF_DIBV5 because the BITMAPV5HEADER structure has a field bV5AlphaMask . The problem is that there doesn't seem to be a consensus as to how exactly the image data should be stored in the clipboard. While doing some tests I found out that there are several differences betweeen the applications making it next to impossible to come up with a general solution. Here are my observations: When I copy an alpha channel image from Word 2010 or

On OpenGL-ES i'm confused on what the difference is between setting glOrthof() glViewPort() GLU.gluOrtho2D() with it's respective parameters. Since I believe it's all setting the part you can see to the specified coordinates (width, height). Which should I use? The glViewport determins the portion of the window to which OpenGL is drawing to. This may be the entire window, or a subsection (think console game's "split screen" mode- a different viewport for every player). glOrthof applies an orthographic projection to the current matrix, which is usually set to the projection matrix before this

Calculating the area of a simple irregular polygon is trivial . However, consider the self-intersecting polygon ABCDEF shown at left below: If we use the linked-to formula above traversing the points in polygon order, we get an area of 0. (The 'clockwise' area cancels out the 'counter-clockwise' area.) However, if we sort the points radially around a center and calculate the area, we get the incorrect area of the polygon ABEDCF at right above. How can I best find the visible area of a self-intersecting polygon? (If the answer requires creating phantom points for each intersection, please

I have a cubic bezier with 2 control points. Starting point and control points are known. Need to get all the points of the curve, given the control, starting and ending points. What I wanna to achieve is ..given a value i from 1 to length of curve.. get the X and Y and alpha (angle) of each point in that position. I cannot find a good reference or working code for that. I'm using javascript. Rahul Banerjee If I understand correctly, you are trying to determine the position and slope (tangent to the curve) of the Bezier, at every point. Let's assume that your start point is (ax, ay), the end

I'm trying to draw a basic 2d ground mesh made up of smaller tiles from a texture atlas (note the 1 pixel transparent border): I render the tiles as texture quads using the following code: glEnable(GL_TEXTURE_2D); glBindTexture(GL_TEXTURE_2D, m_texture); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glVertexPointer(2, GL_SHORT, 0, &m_coords[0]); glTexCoordPointer(2, GL_FLOAT, 0, &m_uvs[0]); glDrawArrays(GL_TRIANGLES, 0, m