When checking for errors, I get [EDIT:] 1282 (“invalid operation”). I take this to mean that the OpenGL is still using OpenGL 2 for glTexImage2D, and so the call is failing. OpenGL errors are not that complex to understand. GL_INVALID_ENUM/VALUE are thrown when you pass something an enum or value that is unexpected, unsupported, or … Read more
Have a look at this picture: Graphical Projections The glOrtho command produces an “Oblique” projection that you see in the bottom row. No matter how far away vertexes are in the z direction, they will not recede into the distance. I use glOrtho every time I need to do 2D graphics in OpenGL (such as … Read more
Well, here’s another example. Xfire is a chat program that overlays its interface into games so you can receive messages while playing. The way they do this is by editing the d3d/opengl DLL at the process memory level, like injecting assembly jumps. I know this because their method was causing my mod to crash, and … Read more
Sounds like you want constructive solid geometry. Carve might do what you want. If you just want run-time rendering OpenCSG will work.
Perhaps the following illustration showing the relationship between the various spaces will help: Depending if you’re using the fixed-function pipeline (you are if you call glMatrixMode(), for example), or using shaders, the operations are identical – it’s just a matter of whether you code them directly in a shader, or the OpenGL pipeline aids in … Read more
Now, my question is for the elbow. Why is there a translation forward on the x-axis both before and after the rotate? If you want to imagine how the matrix operations change the model, then you need to “read” the operations in the reverse order. This is, because the current matrix of the matrix stack … Read more
If you have to following rectangle, where the red cross is the center of the world and you want to rotate it around the green pivot then you’ve to do the following steps: Translate the rectangle in that way that way, that the pivot is on the origin of the world. This is a translation … Read more
Can you use C++11? If so you could use raw string literals: const GLchar* vert = R”END( #version 120 attribute vec2 position; void main() { gl_Position = vec4( position, 0.0, 1.0 ); } )END”; No need for escapes or explicit newlines. These strings start with an R (or r). You need a delimiter (I chose … Read more
matrix notation used in opengl documentation does not describe in-memory layout for OpenGL matrices If think it’ll be easier if you drop/forget about the entire “row/column-major” thing. That’s because in addition to row/column major, the programmer can also decide how he would want to lay out the matrix in the memory (whether adjacent elements form … Read more
// Get the number of vertices obj_file >> md->vertices; // Get the number of faces obj_file >> md->faces; Read the spec again. That’s not how OBJs work. You have to parse out the vertexes/texture coordinates/normals/faces as you go along. Use something like this: #include <GL/glut.h> #include <glm/glm.hpp> #define GLM_ENABLE_EXPERIMENTAL #include <glm/gtx/component_wise.hpp> #include <vector> #include <fstream> … Read more