bgl.glGetUniformLocation() wrongly always returns -1 #83203

New Issue

stephen leger · 2020-11-29T22:24:24+01:00

stephen leger commented

2020-11-29 22:24:24 +01:00

System Information
Operating system: Mint 20
Graphics card: Nvidia 1070

Blender Version
Broken: 2.91.0-906ff7b8fea8-linux64 (maybe sooner, cant tell and will no more work later)
Worked: 2.91.0-2c61c3d733cf-linux64

Short description of error
bgl.glGetUniformLocation() wrongly always returns -1

Exact steps for others to reproduce the error

Open a console and run

import gpu
import bgl

vert_3d = '''
uniform mat4 MVP;

in vec3 pos;
in float primitive_id;
out float primitive_id_var;

void main()
{
    primitive_id_var = primitive_id;
    gl_Position = MVP * vec4(pos, 1.0);
    
}
'''


primitive_id_frag = '''
uniform float offset;
in float primitive_id_var;
out vec4 fragColor;

void main()
{
    fragColor = vec4(offset + primitive_id_var, 0, 0, 0);
}
'''
shader = gpu.types.GPUShader(vert_3d, primitive_id_frag)
bgl.glGetUniformLocation(shader.program, 'MVP')

under working version, should return 0, now returns -1
i guess there are also other bgl.xx affected like setting uniform, but still not certain about this.

As far as i can see there is nothing in doc / release notes about deprication so i bet it is a bug.

**System Information** Operating system: Mint 20 Graphics card: Nvidia 1070 **Blender Version** Broken: 2.91.0-906ff7b8fea8-linux64 (maybe sooner, cant tell and will no more work later) Worked: 2.91.0-2c61c3d733cf-linux64 **Short description of error** bgl.glGetUniformLocation() wrongly always returns -1 **Exact steps for others to reproduce the error** Open a console and run ``` import gpu import bgl vert_3d = ''' uniform mat4 MVP; in vec3 pos; in float primitive_id; out float primitive_id_var; void main() { primitive_id_var = primitive_id; gl_Position = MVP * vec4(pos, 1.0); } ''' primitive_id_frag = ''' uniform float offset; in float primitive_id_var; out vec4 fragColor; void main() { fragColor = vec4(offset + primitive_id_var, 0, 0, 0); } ''' shader = gpu.types.GPUShader(vert_3d, primitive_id_frag) bgl.glGetUniformLocation(shader.program, 'MVP') ``` under working version, should return 0, now returns -1 i guess there are also other bgl.xx affected like setting uniform, but still not certain about this. As far as i can see there is nothing in doc / release notes about deprication so i bet it is a bug.

stephen leger commented

2020-11-29 22:24:24 +01:00

Added subscriber: @StephenLeger

Erik Abrahamsson commented

2020-11-30 01:06:05 +01:00

Added subscriber: @erik85

Erik Abrahamsson commented

2020-11-30 01:06:05 +01:00

No idea if this is a bug or not, but you can also use shader.uniform_from_name("MVP").

No idea if this is a bug or not, but you can also use `shader.uniform_from_name("MVP")`.

stephen leger commented

2020-11-30 01:32:32 +01:00

I guess it is only the tip of the iceberg, where shader.program is no more compatible with bgl.things, facing with many other issues probably related.

Germano Cavalcante commented

2020-11-30 01:58:13 +01:00

Added subscribers: @fclem, @mano-wii

Germano Cavalcante commented

2020-11-30 01:58:13 +01:00

Changed status from 'Needs Triage' to: 'Confirmed'

Germano Cavalcante commented

2020-11-30 01:58:13 +01:00

The problem is that shader.program now always returns 0!
This looks like a bug, but apparently this is intentional:
https://developer.blender.org/diffusion/B/browse/master/source/blender/gpu/intern/gpu_shader.cc$594-599

Introduced in 216d78687

This may be a limitation due to the transition to another render API.

@fclem, are there plans to make shader.program work again?

The problem is that `shader.program` now always returns `0`! This looks like a bug, but apparently this is intentional: https://developer.blender.org/diffusion/B/browse/master/source/blender/gpu/intern/gpu_shader.cc$594-599 Introduced in 216d78687 This may be a limitation due to the transition to another render API. @fclem, are there plans to make `shader.program` work again?

Clément Foucault commented

2020-11-30 13:58:31 +01:00

This shouldn't have been broken. It's going to be deprecated but until then it should work.

stephen leger commented

2020-11-30 14:05:45 +01:00

Was able to workaround by compile shader and create program by hand through bgl.
Hope bgl will remains at least until we get some kind of replacement -with read buffers ability- / or a full implementation of cad like snap system.

Was able to workaround by compile shader and create program by hand through bgl. Hope bgl will remains at least until we get some kind of replacement -with read buffers ability- / or a full implementation of cad like snap system.

blender-admin commented

2020-11-30 14:52:46 +01:00

This issue was referenced by f61ad0e101

This issue was referenced by f61ad0e1017bcf924b0529738c08c3a74d1e7476

Clément Foucault commented

2020-11-30 14:55:50 +01:00

Changed status from 'Confirmed' to: 'Resolved'

Clément Foucault closed this issue

2020-11-30 14:55:50 +01:00

Clément Foucault self-assigned this 2020-11-30 14:55:50 +01:00

Thomas Dinges added this to the 2.91 milestone 2023-02-08 16:20:07 +01:00

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bgl.glGetUniformLocation() wrongly always returns -1 #83203