sb7code | Source code and supporting material | 3D Printing library

How to python debug opengl starfield simulation that drawing a black screen? The code seems ok, but obviously something is off. Are there any additional functions such as glGetError that can verify variables to assist in debugging? I believe I have hurdled, coded correctly a glMapBufferRange function call.

UPDATE: With excellent support by Rabbid76 the program is now rendering the same as expected results. Thank you very much!

Expected output:

Support files: starfield_support.zip

Ported from: starfield.cpp

source code:

How to resolve an error that I'm getting trying to assign values to memory allocated by glMapBufferRange This is a problematic function, due to not having casts in python. I am trying to assign values to this memory, though am experiencing the error stated in the title. I have also tried to create a np.array with a dimension of the size material but to no avail. Perhaps just not doing it correctly.

Update and SUCCESS! With the amazing help of Rabbid76 and the fixes first to allocate and be able to assign to glMapBufferRange memory, and then to the sbmloader.py the program renders successfully. Thank you.

Final results also found on my github PythonOpenGLSuperBible7Glut

support files: hdrbloom_support.zip

expected output rendering is what the actual results are rendering:

source code:

Relatively simple program drawing a blank screen. Ported from Superbible Opengl 7th ed.

The program is currently drawing a blank screen. Although the textoverlay is working correctly.

Update: Added the use of glGetError to add additional error checking. Though there is no error produced by it. Still a blank screen however.

Update and SUCCESS: The program is now rendering the hdr image perfect. Thanks to Rabbid76 excellent answer. It was also a ktxloader that needed a fix. Thank you.

Expected output is:

support files: hdrexposure_support.zip

ported from: hdrexposure.cpp

source code:

Run into an error with the glDrawBuffer function. I am porting Figure 9.8 of Superbible OpenGL 7th ed. p.457. Any help will be greatly appreciated. Thank you.

supporting files: stereo_support.zip

expected output:

Figure 8.27 of Superbible OpenGL 7th ed. has been ported to python although I am experiencing an error with the glMapBufferRange once more. This time to allocate a glm.mat4 I have tried to convert it to native ctypes.sizeof(ctypes.c_float) * 16 to no avail. Please help. Thank you.

Update: An excellent answer has been provided by Rabbid76. I was able to fix the problem and now the program renders the 4 spinning cubes. Thank you very much!

expected output:

Current output: error 1282, glMapBufferRange, invalid operation

Support file: multiviewport_support.zip

Source code:

I am trying to port an example from chapter 8 of the Superbible OpenGL 7th ed. and the control cage lines are not going from point to point as in the example gif or the image on page 375 of the book. Instead its rendering the lines to just a single point. I have provided it below. Thank you.

Expected output:

Actual output I am receiving:

Support files: cubicbezier_support.zip

The source is of a green dragon rendering. My question is how to get the clip distances working on it? Also, the textures are not appearing as the expected output. Any ideas what can be modified in the source code to render the program as expected?

Update: With the excellent help and superb answers of Rabbid76 the clip distance is working and texture loading is working! Thank You.

Bonus example: clipdistance_torus_package.zip a clip distance example with a torus and textures!

Expected output:

Files to run: clipdistance_dragon.zip

So I'm having problem with the opengl function glBeginTransformFeedback When I uncomment the lines, an error is occurring. It says 1282 invalid operation though that's quite vague.

My question is what should be done with the source code to uncomment these three lines:

I'm porting a program to learn about indirect draws from Superbible OpenGL 7th ed. This program is supposed to render almost 1 billion vertices per second and does not get a bottleneck from the rate of submitting draw commands due to using a modern opengl technique of glMultiDrawArraysIndirect Any help would be appreciated. Thank You.

this is the expected output:

Update: I'm very grateful for the wonderful help from the Rabbid76 answer. The code is so good and the insight as to why is refreshing and amazing. Thank you so much! The program is displaying the asteroid field as intended!

It does appear that the program runs faster with the indirect draws.

I agree don't seem to use enum as a class right in python. Plus its probably better not to.

dependency files: asteroids_support.zip there's an updated sbmloader in the zip

source code of asteroids.py