opengl-3

I was recently writing some OpenGL 3.3 code with Vertex Array Objects (VAO) and tested it later on Intel graphics adapter where I found, to my disappointment, that element array buffer binding is evidently not part of VAO state, as calling: glBindVertexArray(my_vao); glDrawElements(GL_TRIANGLE_STRIP, count, GL_UNSIGNED_INTEGER, 0); had no effect, while: glBindVertexArray(my_vao); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, my_index_buffer); // ? glDrawElements(GL_TRIANGLE_STRIP, count, GL_UNSIGNED_INTEGER, 0); rendered the geometry. I thought it was a mere bug in Intel implementation of OpenGL

I'm trying to read some OpenGL tutorials on the net. the problem is that I found some old ones that use gluPerspective() . gluPerspective was deprecated in OpenGL 3.0 and removed in 3.1. What function can I use instead? I'm using C++ with latest FreeGlut installed. Dan You have to compute the matrix manually and then pass it to OpenGL. Computing the matrix This snippet of code is based on the gluPerspective documentation . void BuildPerspProjMat(float *m, float fov, float aspect, float znear, float zfar) { float f = 1/tan(fov * PI_OVER_360); m[0] = f/aspect; m[1] = 0; m[2] = 0; m[3] = 0; m[4]

I am using OpenGL3.2 Core Profile on OSX. And I want to do instanced drawing (glDrawArraysInstanced), where I pass a matrix for each instance. My vertex shader builds just fine: #version 150 in mediump vec4 position; in mediump mat4 trf; in lowp vec4 rgb; out lowp vec4 colour; uniform highp mat4 modelcamviewprojmat; void main() { mediump vec4 tpos = trf * position; gl_Position = modelcamviewprojmat * tpos; colour = rgb; } The binding of 'trf' went fine: glBindAttribLocation(program, ATTRIB_TRF, "trf" ); But how can I pass in my data? glVertexAttribPointer can not pass values larger than 4

I understand that OpenGL 4 and 3 are fairly similar, especially 3.1 and 4.1. With both being essentially released together, it can be difficult to understand the rationale for OpenGL 4.0/4.1. In previous releases of OpenGL, minor version increments upward until substantial changes accumulated into a new major version. OpenGL 3.x and 4.x introduced backwards-incompatible API changes and then OpenGL 3.2 and 3.3 are said to be specifically branches of the 3 series which are not forward compatible while 3.1 is compatible with 4.1+ What key differences does OpenGL 4.1 offer compared with OpenGL 3.1

I'm running that configuration : Ubuntu 12.04 Intel HD Graphics 4000 glxinfo give me that parameters: OpenGL renderer string: Mesa X11 OpenGL version string: 2.1 Mesa 8.0.4 OpenGL shading language version string: 1.20 OpenGL extensions: My goal was to run OpenGL 3.3 (and so GLSL 3.3). If I'm easy with development issues, I'm lost in hardware and drivers, so does someone knows a way to achieve that with my configuration? Unfortunally at this moment it looks like this is not possible, since the open source drivers provided by Intel are the only available. There is a version newer than yours

Im facing an issue which I believe to be VAO-dependant, but Im not sure.. I am not sure about the correct usage of a VAO, what I used to do during GL initialization was a simple glGenVertexArrays(1,&vao) followed by a glBindVertexArray(vao) and later, in my drawing pipeline, I just called glBindBuffer(), glVertexAttribPointer(), glEnableVertexAttribArray() and so on.. without caring about the initally bound VAO is this a correct practice? VAOs act similarly to VBOs and textures with regard to how they are bound. Having a single VAO bound for the entire length of your program will yield no