1
vote
1answer
80 views

How do I flip upside down fonts in FTGL [closed]

I just use FTGL to use it in my app. I want to use the version FTBufferFont to render font but it renders in the wrong way. The font(texture?buffer?) is flipped in the wrong axis. I want to use ...
2
votes
1answer
116 views

Is it bad-practice using left-handed coordinate system in OpenGL eye-space?

In the engine I am currently programming I want to use a left-handed coordinate system for eye-space instead of the glFrustum standard right-handed one. Is that in anyway considered bad practice?
1
vote
0answers
203 views

c++ opengl unproject not working

first of all, sorry for the bad english. I need to convert my mouse coordinates to world coordinates, I'm trying to use the glm unproject method. 1280x720 is the size of the window, It's hard coded ...
4
votes
1answer
109 views

Can you help me solve the paradox that has confused me about the glViewport and glOrtho functions?

suppose that I have an image that I want to apply as a texture on a geometry (at time we don't consider texture mapping but this image has a certain width and height here it is a 512x512 image) I want ...
1
vote
0answers
74 views

Rotate view matrix based on touch coordinates

I'm working on an Android game where I need to rotate the camera around the origin based on the user dragging their finger. My view matrix has initial position of sitting on the negative z and facing ...
0
votes
1answer
172 views

Ways to “invert Z-axis” in shader-based core-profile OpenGL?

In my hobbyist shader-based (non-FFP) GL (3.2+ core) "engine", everything in world-space and model-space is by design "left-handed" (and to stay that way), so X-axis goes from -1 ("left") to 1 ...
13
votes
1answer
369 views

Orthographic unit translation mismatch on grid (e.g. 64 pixels translates incorrectly)

I am looking for some insight into a small problem with unit translations on a grid. Update and Solved I solved my own issue. See below for details. Everything in this part of the post turned out to ...
4
votes
1answer
300 views

Translation from one coordinate system to another having Z-offset issues

I'm using ARToolkit to do an augmented reality application, but my problem is really with the 3D coordinates. In this application, I use my webcam to generate the scene. I have two markers (printed ...
3
votes
3answers
390 views

The ship “shudders” in scrolling Asteroids

In my Asteroids game the user can scroll through space. When scrolling, the ship is drawn in the centre of the window. I use interpolation. I scroll the window uing glOrtho, centering it around the ...
2
votes
2answers
2k views

gluLookAt vs glTranslate + glRotate and camera transformation matrices

I'm getting my hands dirty in OpenGL and something is bothering me a bit. It's my understanding from reading about the subject that a call to gluLookAt basically multiplies a matrix on the stack that ...
2
votes
1answer
3k views

Converting 3D coordinates to 2D and back?

I'm wondering if there is a simple way to convert 3D coordinates to 2D coordinates. Also, if it's possible, to convert in the reverse direction. I'm using OpenGL(GLUT) in my C++ project. I am also ...