• Kevin (8/8) Jan 09 2017 Using Archlinux, Derelict-gl3 1.0.18
• Mike Parker (28/36) Jan 09 2017 This has nothing to do with Derelict. It's an error in your use
• Kevin (107/147) Jan 10 2017 Thanks for info. I already did glGetError() above and below.
• Kevin (4/13) Jan 10 2017 You are right. My simple mistake.
• Jerry (3/3) Jan 12 2017 Don't use glGetError() it was such a horrible design decision to

Kevin <kdrakemagi gmail.com> writes:

Using Archlinux, Derelict-gl3 1.0.18
check format (GLuint, Glenum, Glint*)

// this does not work
glGetShaderiv(program, GL_LINK_STATUS, &success);
writeln("GL_ERROR: ", glGetError());

Give me error 1282

// this one works fine.
glGetShaderiv(shader, GL_COMPILE_STATUS, &success);

Mike Parker <aldacron gmail.com> writes:

On Tuesday, 10 January 2017 at 01:43:50 UTC, Kevin wrote:
 Using Archlinux, Derelict-gl3 1.0.18
 check format (GLuint, Glenum, Glint*)

 // this does not work
 glGetShaderiv(program, GL_LINK_STATUS, &success);
 writeln("GL_ERROR: ", glGetError());

 Give me error 1282

 // this one works fine.
 glGetShaderiv(shader, GL_COMPILE_STATUS, &success);

This has nothing to do with Derelict. It's an error in your use 
of OpenGL, so you need to look up the OpenGL error code 1282 and 
figure out what it means.

Since I'm here, I'll save you some time. 1282 is 
GL_INVALID_OPERATION. However, just because you called it 
immediately after glGetShaderiv *does not mean* that function 
caused the error. The error code may have been set any time 
before that, by any of the functions you called. Then, when you 
call glGetError, the error code is reset to 0, so your next call 
to glGetError shows no error.

Here's some psuedocode to illustrate:

// OpenGL's internal error code
errCode = 0;

// In your code:
glSomething(); // no error
glSomethingElse(); // no error
glAnotherThing();  // Oops! An error - errCode now is set to 1282
glThisThing();  // No error, but the state is now messed up
glThatThing();  // No error
err = glGetError();  // This returns 1282, as set by 
glAnotherThing above


What you need to do is debug your OpenGL code. The simplest way 
to do that is to insert glGetError at different points, 
recompile, and run it again. This will help you narrow things 
down to the function that actually caused the error.

And for future reference, please go to opengl.org or the OpenGL 
forums at gamedev.net for help with OpenGL.

Kevin <kdrakemagi gmail.com> writes:

On Tuesday, 10 January 2017 at 04:34:24 UTC, Mike Parker wrote:
 On Tuesday, 10 January 2017 at 01:43:50 UTC, Kevin wrote:
 Using Archlinux, Derelict-gl3 1.0.18
 check format (GLuint, Glenum, Glint*)

 // this does not work
 glGetShaderiv(program, GL_LINK_STATUS, &success);
 writeln("GL_ERROR: ", glGetError());

 Give me error 1282

 // this one works fine.
 glGetShaderiv(shader, GL_COMPILE_STATUS, &success);

 This has nothing to do with Derelict. It's an error in your use 
 of OpenGL, so you need to look up the OpenGL error code 1282 
 and figure out what it means.

 Since I'm here, I'll save you some time. 1282 is 
 GL_INVALID_OPERATION. However, just because you called it 
 immediately after glGetShaderiv *does not mean* that function 
 caused the error. The error code may have been set any time 
 before that, by any of the functions you called. Then, when you 
 call glGetError, the error code is reset to 0, so your next 
 call to glGetError shows no error.

 Here's some psuedocode to illustrate:

 // OpenGL's internal error code
 errCode = 0;

 // In your code:
 glSomething(); // no error
 glSomethingElse(); // no error
 glAnotherThing();  // Oops! An error - errCode now is set to 
 1282
 glThisThing();  // No error, but the state is now messed up
 glThatThing();  // No error
 err = glGetError();  // This returns 1282, as set by 
 glAnotherThing above


 What you need to do is debug your OpenGL code. The simplest way 
 to do that is to insert glGetError at different points, 
 recompile, and run it again. This will help you narrow things 
 down to the function that actually caused the error.

 And for future reference, please go to opengl.org or the OpenGL 
 forums at gamedev.net for help with OpenGL.

Thanks for info. I already did glGetError() above and below.
and it only from that code. At first I thought i put the wrong 
type. I set success to 1 and let code go through and shader work 
fine. The glGetShaderiv(program, GL_LINK_STATUS, &success) check 
does not work. If you still think it opengl problem I will take 
it there or maybe i made a simple mistake I can't see.

full code
import std.string : toStringz;
import std.stdio;
import std.file;

import derelict.opengl3.gl;

struct Shader {
   private GLuint program;

    disable this(this);

   ~this() {
     glDeleteProgram(program);
   }

   void use() {
     glUseProgram(program);
   }

   bool create(string vertexName, string fragmentName, string 
geometryName=null) {
     char[512] infoLog;
     program = 0;
     GLuint vertexShader = shaderFile(vertexName, 
GL_VERTEX_SHADER);
     GLuint fragmentShader = shaderFile(fragmentName, 
GL_FRAGMENT_SHADER);
     GLuint geometryShader = 0;
     GLint success = 1;

     if(geometryName !is null)
       geometryShader = shaderFile(geometryName, 
GL_GEOMETRY_SHADER);

     if(vertexShader == 0) {
       writeln("Vertex is null");
       return false;
     }

     if(fragmentShader == 0) {
       writeln("Fragment is null");
       glDeleteShader(vertexShader);
       return false;
     }

     if(geometryName !is null) {
       if(geometryShader == 0) {
         writeln("Geometry is null");
         glDeleteShader(vertexShader);
         glDeleteShader(fragmentShader);
         return false;
       }
     }

     // create program
     program = glCreateProgram();
     glAttachShader(program, vertexShader);
     glAttachShader(program, fragmentShader);
     if(geometryName !is null)
       glAttachShader(program, geometryShader);

     glLinkProgram(program);
     writeln("Before GL_ERROR: ", glGetError());

     // this does not work
     glGetShaderiv(program, GL_LINK_STATUS, &success);
     writeln("After GL_ERROR: ", glGetError());
     if(!success) {
       writeln("GL_ERROR: ", glGetError());
       glGetShaderInfoLog(program, 512, null, infoLog.ptr);
       writeln("ERROR::Shader program linking failed");
       writeln(infoLog);
     }

     glDeleteShader(vertexShader);
     glDeleteShader(fragmentShader);
     if(geometryName !is null)
       glDeleteShader(geometryShader);

     return cast(bool) success;
   }

   private GLuint shaderFile(string sourceName, GLenum flag) {
     string fileData;
     GLchar* source;
     GLint success;
     GLchar[512] infoLog;
     GLuint shader = 0;

     if(exists(sourceName) != 0)
       fileData = cast(string) read(sourceName);
     else {
       writeln("ERROR: File doesn't exist");
       return 0;
     }

     source = cast(GLchar*) (toStringz(fileData));
     shader = glCreateShader(flag);
		glShaderSource(shader, 1, &source, null);
		glCompileShader(shader);

     // this one work fine
     glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
     writeln("sh .. GL_ERROR: ", glGetError());
		if(!success)
		{
			glGetShaderInfoLog(shader, 512, null, infoLog.ptr);
       if(flag == GL_VERTEX_SHADER)
         writeln("ERROR::Shader vertex compiltion failed ");
       else if(flag == GL_FRAGMENT_SHADER)
         writeln("ERROR::Shader fragment compiltion failed");
       else if(flag == GL_GEOMETRY_SHADER)
         writeln("ERROR::Shader geometry compiltion failed");

       writeln(infoLog);
		}

     return shader;
   }
}

Kevin <kdrakemagi gmail.com> writes:

On Tuesday, 10 January 2017 at 14:32:29 UTC, Kevin wrote:
 On Tuesday, 10 January 2017 at 04:34:24 UTC, Mike Parker wrote:
 [...]

 Thanks for info. I already did glGetError() above and below.
 and it only from that code. At first I thought i put the wrong 
 type. I set success to 1 and let code go through and shader 
 work fine. The glGetShaderiv(program, GL_LINK_STATUS, &success) 
 check does not work. If you still think it opengl problem I 
 will take it there or maybe i made a simple mistake I can't see.

 [...]

You are right. My simple mistake.
i use glGetShaderiv when I should have us glGetProgramiv.
Thanks for your help.

Jerry <hurricane hereiam.com> writes:

Don't use glGetError() it was such a horrible design decision to 
use that for debugging. A better way to debug was introduced.

https://www.khronos.org/opengl/wiki/Debug_Output