_slang_alloc_statevar alloc_state_var_array emit_statevars lookup_statevar STATE_ARRAY

static GLint alloc_state_var_array ( const slang_variable *  var, struct gl_program_parameter_list *  paramList  ) [static] Unroll the named built-in uniform variable into a sequence of state vars in the given parameter list. Definition at line 584 of file slang_builtin.c. Referenced by _slang_alloc_statevar(). { gl_state_index tokens[STATE_LENGTH]; GLuint i; GLint pos; /* Initialize the state tokens array. This is very important. * When we call _mesa_add_state_reference() it'll searches the parameter * list to see if the given statevar token sequence is already present. * This is normally a good thing since it prevents redundant values in the * constant buffer. * * But when we're building arrays of state this can be bad. For example, * consider this fragment of GLSL code: * foo = gl_LightSource[3].diffuse; * ... * bar = gl_LightSource[i].diffuse; * * When we unroll the gl_LightSource array (for "bar") we want to re-emit * gl_LightSource[3].diffuse and not re-use the first instance (from "foo") * since that would upset the array layout. We handle this situation by * setting the last token in the state var token array to the special * value STATE_ARRAY. * This token will only be set for array state. We can hijack the last * element in the array for this since it's never used for light, clipplane * or texture env array state. */ for (i = 0; i < STATE_LENGTH; i++) tokens[i] = 0; tokens[STATE_LENGTH - 1] = STATE_ARRAY; pos = emit_statevars(var->a_name, var->array_len, &var->type.specifier, tokens, paramList); return pos; }