Using shaders in OpenGL

using the GLSL shader step in OpenGL

The GLSL is suitable for both vertex shaders and fragment shaders.
to use a shader object:

1. Create a Shader object:
Gluint glcreateshader (glenum type);
Creates a shader object, the type value must be Gl_vertex_shader or Gl_fragment_shader. Error returns 0
2. The source of the shader is associated with the shader object:
Glshadersource (Gluint shader, Glsizei count, const glchar** string, const glint* length);
3, compile the source of the shader object:
void Glcompileshader (Gluint shader);
Glgetshaderiv (Gl_cimpile_status); Query compilation results
Glgetshaderinfolog (Gluint shader, Glsizei bufSize, Glsizei *length, char* infoLog);
4. Create an empty shader program:
Gluint Glcreateprogram (); If error, return 0;
5. Connect the shader object to the shader program:
Glattachshader (gluint program, gluint Shader); Gldetachshader (program, shader);
6. Link the objects connected to the shader program into an executable program:
Voi Gllinkprogram (gluint program);
GLGETPROGRAMIV (Gl_link_status); Query link results, Gl_true represent success
Glgetprograminfolog (Gluint shader, Glsizei bufSize, Glsizei *length, char* infoLog);
7. Start the vertex or fragment shader program:
void Gluseprogram (Gluint program); Using the program's object handle as a parameter
eg

Gluint Shader,program; Gluint compiled, linked;const glchar* shadersrc[] = {"void main () {" "Gl_position = Gl_modelviewprojectionmatrix *gl_vertex; "}"}; Shader = Glcreateshader (Gl_vertex_shader); Glshadersource (shader, 1, shadersrc, NULL); Glcompileshader (shader);    Glgetshaderinfolog (shader, Gl_compile_status, &compiled); if (!compiled) {glint length;    glchar* log;    Glgetshaderiv (shader, Gl_info_log_length, &length);    Log = (glchar*) malloc (length);    Glgetshaderinfolog (shader, length, &length, log);    fprintf (stderr, "compile log = '%s ' \ n", log); Free (log);} Program =glcreateprogram (); Glattachshader (program, shader); Gllinkprogram (program); GLGETPROGRAMIV (program, Gl_link _status, &linked); if (linker) {Gluseprogram (program);}    else{glint length;    glchar* log;    GLGETPROGRAMIV (program, Gl_info_log_length, &length);    Log = (glchar*) malloc (length);    Glgetprograminfolog (program, length, &length, log); fprintf (stderr, "link log = '%s ')\ n ", log); Free (log);}

To delete a shader:

void Gldeleteshader (Gluint shader); If it is being used, it is marked as deleted and deleted after use.
Determine if the shader program name is valid:
Glboolean Glisprogram (gluint program); Gl_true
Verify that a shader can be executed in the current OpenGL state:
void Glvalidateprogram (Gluint program);

If validation passes, Gl_validate_status is set to Gl_true, calling GLGETPROGRAMIV () to query the value of Gl_validate_status.

Using shaders in OpenGL