XAllocStandardColormap(3X11)AIX (XLIB FUNCTIONS)XAllocStandardColormap(3X11) NAME XAllocStandardColormap, XSetRGBColormaps, XGetRGBColormaps, XStandardColormap - allocate, set, or read a standard color- map structure SYNTAX XStandardColormap *XAllocStandardColormap() void XSetRGBColormaps(_d_i_s_p_l_a_y, _w, _s_t_d__c_o_l_o_r_m_a_p, _c_o_u_n_t, _p_r_o_- _p_e_r_t_y) Display *_d_i_s_p_l_a_y; Window _w; XStandardColormap *_s_t_d__c_o_l_o_r_m_a_p; int _c_o_u_n_t; Atom _p_r_o_p_e_r_t_y; Status XGetRGBColormaps(_d_i_s_p_l_a_y, _w, _s_t_d__c_o_l_o_r_m_a_p__r_e_t_u_r_n, _c_o_u_n_t__r_e_t_u_r_n, _p_r_o_p_e_r_t_y) Display *_d_i_s_p_l_a_y; Window _w; XStandardColormap **_s_t_d__c_o_l_o_r_m_a_p__r_e_t_u_r_n; int *_c_o_u_n_t__r_e_t_u_r_n; Atom _p_r_o_p_e_r_t_y; ARGUMENTS _d_i_s_p_l_a_y Specifies the connection to the X server. _c_o_u_n_t Specifies the number of colormaps. _c_o_u_n_t__r_e_t_u_r_n Returns the number of colormaps. _p_r_o_p_e_r_t_y Specifies the property name. _s_t_d__c_o_l_o_r_m_a_p Specifies the _X_S_t_a_n_d_a_r_d_C_o_l_o_r_m_a_p structure to be used. _s_t_d__c_o_l_o_r_m_a_p__r_e_t_u_r_n Returns the _X_S_t_a_n_d_a_r_d_C_o_l_o_r_m_a_p structure. DESCRIPTION The _X_A_l_l_o_c_S_t_a_n_d_a_r_d_C_o_l_o_r_m_a_p function allocates and returns a pointer to a _X_S_t_a_n_d_a_r_d_C_o_l_o_r_m_a_p structure. Note that all fields in the _X_S_t_a_n_d_a_r_d_C_o_l_o_r_m_a_p structure are initially set to zero. If insufficient memory is available, _X_A_l_l_o_c_S_t_a_n_- _d_a_r_d_C_o_l_o_r_m_a_p returns NULL. To free the memory allocated to this structure, use _X_F_r_e_e. The _X_S_e_t_R_G_B_C_o_l_o_r_m_a_p_s function replaces the RGB colormap definition in the specified property on the named window. If the property does not already exist, _X_S_e_t_R_G_B_C_o_l_o_r_m_a_p_s sets the RGB colormap definition in the specified property Rev. Release 5 Page 1 XAllocStandardColormap(3X11)AIX (XLIB FUNCTIONS)XAllocStandardColormap(3X11) on the named window. The property is stored with a type of RGB_COLOR_MAP and a format of 32. Note that it is the caller's responsibility to honor the ICCCM restriction that only RGB_DEFAULT_MAP contain more than one definition. The _X_S_e_t_R_G_B_C_o_l_o_r_m_a_p_s function usually is only used by window or session managers. To create a standard colormap, follow this procedure: 1. Open a new connection to the same server. 2. Grab the server. 3. See if the property is on the property list of the root window for the screen. 4. If the desired property is not present: o+ Create a colormap (unless using the default color- map of the screen). o+ Determine the color characteristics of the visual. o+ Call _X_A_l_l_o_c_C_o_l_o_r_P_l_a_n_e_s or _X_A_l_l_o_c_C_o_l_o_r_C_e_l_l_s to allocate cells in the colormap. o+ Call _X_S_t_o_r_e_C_o_l_o_r_s to store appropriate color values in the colormap. o+ Fill in the descriptive members in the _X_S_t_a_n_d_a_r_d_- _C_o_l_o_r_m_a_p structure. o+ Attach the property to the root window. o+ Use _X_S_e_t_C_l_o_s_e_D_o_w_n_M_o_d_e to make the resource per- manent. 5. Ungrab the server. _X_S_e_t_R_G_B_C_o_l_o_r_m_a_p_s can generate _B_a_d_A_l_l_o_c, _B_a_d_A_t_o_m, and _B_a_d_W_i_n_- _d_o_w errors. The _X_G_e_t_R_G_B_C_o_l_o_r_m_a_p_s function returns the RGB colormap definitions stored in the specified property on the named window. If the property exists, is of type RGB_COLOR_MAP, is of format 32, and is long enough to contain a colormap definition, _X_G_e_t_R_G_B_C_o_l_o_r_m_a_p_s allocates and fills in space for the returned colormaps and returns a nonzero status. If the visualid is not present, _X_G_e_t_R_G_B_C_o_l_o_r_m_a_p_s assumes the default visual for the screen on which the window is located; if the killid is not present, _N_o_n_e is assumed, which indicates that the resources cannot be released. Oth- erwise, none of the fields are set, and _X_G_e_t_R_G_B_C_o_l_o_r_m_a_p_s Rev. Release 5 Page 2 XAllocStandardColormap(3X11)AIX (XLIB FUNCTIONS)XAllocStandardColormap(3X11) returns a zero status. Note that it is the caller's respon- sibility to honor the ICCCM restriction that only RGB_DEFAULT_MAP contain more than one definition. _X_G_e_t_R_G_B_C_o_l_o_r_m_a_p_s can generate _B_a_d_A_t_o_m and _B_a_d_W_i_n_d_o_w errors. STRUCTURES The _X_S_t_a_n_d_a_r_d_C_o_l_o_r_m_a_p structure contains: /* Hints */ lw(.5i) lw(2i) lw(1i). T{ #define T} T{ _R_e_l_e_a_s_e_B_y_F_r_e_e_i_n_g_C_o_l_o_r_m_a_p T} T{ ( (XID) 1L) T} /* Values */ typedef struct { Colormap colormap; unsigned long red_max; unsigned long red_mult; unsigned long green_max; unsigned long green_mult; unsigned long blue_max; unsigned long blue_mult; unsigned long base_pixel; VisualID visualid; XID killid; } XStandardColormap; The colormap member is the colormap created by the _X_C_r_e_a_t_e_C_o_l_o_r_m_a_p function. The red_max, green_max, and blue_max members give the maximum red, green, and blue values, respectively. Each color coefficient ranges from zero to its max, inclusive. For example, a common colormap allocation is 3/3/2 (3 planes for red, 3 planes for green, and 2 planes for blue). This colormap would have red_max = 7, green_max = 7, and blue_max = 3. An alternate allocation that uses only 216 colors is red_max = 5, green_max = 5, and blue_max = 5. The red_mult, green_mult, and blue_mult members give the scale factors used to compose a full pixel value. (See the discussion of the base_pixel members for further informa- tion.) For a 3/3/2 allocation, red_mult might be 32, green_mult might be 4, and blue_mult might be 1. For a 6- colors-each allocation, red_mult might be 36, green_mult might be 6, and blue_mult might be 1. The base_pixel member gives the base pixel value used to compose a full pixel value. Usually, the base_pixel is obtained from a call to the _X_A_l_l_o_c_C_o_l_o_r_P_l_a_n_e_s function. Given integer red, green, and blue coefficients in their appropriate ranges, one then can compute a corresponding pixel value by using the following expression: (r * red_mult + g * green_mult + b * blue_mult + base_pixel) & 0xFFFFFFFF For _G_r_a_y_S_c_a_l_e colormaps, only the colormap, red_max, Rev. Release 5 Page 3 XAllocStandardColormap(3X11)AIX (XLIB FUNCTIONS)XAllocStandardColormap(3X11) red_mult, and base_pixel members are defined. The other members are ignored. To compute a _G_r_a_y_S_c_a_l_e pixel value, use the following expression: (gray * red_mult + base_pixel) & 0xFFFFFFFF Negative multipliers can be represented by converting the 2's complement representation of the multiplier into an unsigned long and storing the result in the appropriate _mult field. The step of masking by 0xFFFFFFFF effectively converts the resulting positive multiplier into a negative one. The masking step will take place automatically on many machine architectures, depending on the size of the integer type used to do the computation, The visualid member gives the ID number of the visual from which the colormap was created. The killid member gives a resource ID that indicates whether the cells held by this standard colormap are to be released by freeing the colormap ID or by calling the _X_K_i_l_l_C_l_i_e_n_t function on the indicated resource. (Note that this method is necessary for allocat- ing out of an existing colormap.) The properties containing the _X_S_t_a_n_d_a_r_d_C_o_l_o_r_m_a_p information have the type RGB_COLOR_MAP. DIAGNOSTICS _B_a_d_A_l_l_o_c The server failed to allocate the requested resource or server memory. _B_a_d_A_t_o_m A value for an Atom argument does not name a defined Atom. _B_a_d_W_i_n_d_o_w A value for a Window argument does not name a defined Window. SEE ALSO XAllocColor(3X11), XCreateColormap(3X11), XFree(3X11), XSetCloseDownMode(3X11) _X_l_i_b - _C _L_a_n_g_u_a_g_e _X _I_n_t_e_r_f_a_c_e Rev. Release 5 Page 4