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XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) NNNNAAAAMMMMEEEE XSGIvcStoreGammaColors8, XSGIvcStoreGammaColors16, XSGIvcQueryGammaColors, XSGIvcQueryScreenGammaMaps, XSGIvcQueryGammaMap, XSGIvcSetChannelGammaMap, XSGIvcQueryChannelGammaMap - Set and query gamma correction resources SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS ####iiiinnnncccclllluuuuddddeeee <<<<XXXX11111111////eeeexxxxtttteeeennnnssssiiiioooonnnnssss////XXXXSSSSGGGGIIIIvvvvcccc....hhhh>>>> SSSSttttaaaattttuuuussss XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyySSSSccccrrrreeeeeeeennnnGGGGaaaammmmmmmmaaaaMMMMaaaappppssss((((DDDDiiiissssppppllllaaaayyyy ****ddddiiiissssppppllllaaaayyyy,,,, iiiinnnntttt ssssccccrrrreeeeeeeennnn,,,, iiiinnnntttt ****ggggaaaammmmmmmmaaaaMMMMaaaappppssssRRRReeeettttuuuurrrrnnnn)))) SSSSttttaaaattttuuuussss XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaMMMMaaaapppp((((DDDDiiiissssppppllllaaaayyyy ****ddddiiiissssppppllllaaaayyyy,,,, iiiinnnntttt ssssccccrrrreeeeeeeennnn,,,, iiiinnnntttt ggggaaaammmmmmmmaaaaMMMMaaaapppp,,,, iiiinnnntttt ****ggggaaaammmmmmmmaaaaSSSSiiiizzzzeeeeRRRReeeettttuuuurrrrnnnn,,,, iiiinnnntttt ****ggggaaaammmmmmmmaaaaPPPPrrrreeeecccciiiissssiiiioooonnnnRRRReeeettttuuuurrrrnnnn,,,, iiiinnnntttt ****ggggaaaammmmmmmmaaaaMMMMaaaappppAAAAttttttttrrrriiiibbbbuuuutttteeeessss)))) vvvvooooiiiidddd XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss8888((((DDDDiiiissssppppllllaaaayyyy ****ddddiiiissssppppllllaaaayyyy,,,, iiiinnnntttt ssssccccrrrreeeeeeeennnn,,,, iiiinnnntttt ggggaaaammmmmmmmaaaaMMMMaaaapppp,,,, iiiinnnntttt iiiitttteeeemmmmCCCCoooouuuunnnntttt,,,, lllloooonnnngggg llllooooaaaaddddTTTTaaaabbbblllleeeessss ccccoooonnnnsssstttt uuuunnnnssssiiiiggggnnnneeeedddd cccchhhhaaaarrrr ****ggggaaaammmmmmmmaaaaVVVVaaaalllluuuueeee)))) vvvvooooiiiidddd XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss11116666((((DDDDiiiissssppppllllaaaayyyy ****ddddiiiissssppppllllaaaayyyy,,,, iiiinnnntttt ssssccccrrrreeeeeeeennnn,,,, iiiinnnntttt ggggaaaammmmmmmmaaaaMMMMaaaapppp,,,, iiiinnnntttt iiiitttteeeemmmmCCCCoooouuuunnnntttt,,,, lllloooonnnngggg llllooooaaaaddddTTTTaaaabbbblllleeeessss ccccoooonnnnsssstttt uuuunnnnssssiiiiggggnnnneeeedddd sssshhhhoooorrrrtttt ****ggggaaaammmmmmmmaaaaVVVVaaaalllluuuueeee)))) SSSSttttaaaattttuuuussss XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((DDDDiiiissssppppllllaaaayyyy ****ddddiiiissssppppllllaaaayyyy,,,, iiiinnnntttt ssssccccrrrreeeeeeeennnn,,,, iiiinnnntttt ggggaaaammmmmmmmaaaaMMMMaaaapppp,,,, iiiinnnntttt rrrreeeeqqqquuuueeeesssstttteeeeddddCCCCoooolllloooorrrr,,,, iiiinnnntttt ****iiiitttteeeemmmmCCCCoooouuuunnnnttttRRRReeeettttuuuurrrrnnnn,,,, uuuunnnnssssiiiiggggnnnneeeedddd sssshhhhoooorrrrtttt ********ggggaaaammmmmmmmaaaaVVVVaaaalllluuuueeeeRRRReeeettttuuuurrrrnnnn)))) vvvvooooiiiidddd XXXXSSSSGGGGIIIIvvvvccccSSSSeeeettttCCCChhhhaaaannnnnnnneeeellllGGGGaaaammmmmmmmaaaaMMMMaaaapppp((((DDDDiiiissssppppllllaaaayyyy ****ddddiiiissssppppllllaaaayyyy,,,, iiiinnnntttt ssssccccrrrreeeeeeeennnn,,,, iiiinnnntttt cccchhhhaaaannnnnnnneeeellll,,,, iiiinnnntttt ggggaaaammmmmmmmaaaaMMMMaaaapppp)))) SSSSttttaaaattttuuuussss XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyCCCChhhhaaaannnnnnnneeeellllGGGGaaaammmmmmmmaaaaMMMMaaaapppp((((DDDDiiiissssppppllllaaaayyyy ****ddddiiiissssppppllllaaaayyyy,,,, iiiinnnntttt ssssccccrrrreeeeeeeennnn,,,, iiiinnnntttt cccchhhhaaaannnnnnnneeeellll,,,, iiiinnnntttt ****ggggaaaammmmmmmmaaaaMMMMaaaappppRRRReeeettttuuuurrrrnnnn)))) Page 1 (printed 10/3/02) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS _g_a_m_m_a_M_a_p_s_R_e_t_u_r_n Returns the number of gamma maps available on the server. Pass the address of a variable to receive this value. _d_i_s_p_l_a_y Specifies the connection to the X server. _s_c_r_e_e_n Specifies the screen of the X server. _c_h_a_n_n_e_l Specifies the channel number. _g_a_m_m_a_M_a_p Specifies which of the gamma maps within the server should be affected. Gamma map IDs are not X resources, but are numbered implicitly, starting with 0. _i_t_e_m_C_o_u_n_t Specifies the number of elements in the gamma table to be loaded. _i_t_e_m_C_o_u_n_t_R_e_t_u_r_n Specifies a pointer to an integer that is to contain the number of elements in the gamma table. _l_o_a_d_T_a_b_l_e_s The gamma tables which should be loaded with this command. To economize traffic, you should load all tables simultaneously if you intend to set each color component to the same values. You may use a bitwise OR of the constants _X_S_G_I_V_C__M_C_o_m_p_o_n_e_n_t_R_e_d, _X_S_G_I_V_C__M_C_o_m_p_o_n_e_n_t_G_r_e_e_n, _X_S_G_I_V_C__M_C_o_m_p_o_n_e_n_t_B_l_u_e, or _X_S_G_I_V_C__M_C_o_m_p_o_n_e_n_t_A_l_p_h_a. _g_a_m_m_a_V_a_l_u_e Specifies a pointer to an array containing gamma elements. The number of items of each array must be that specified in itemCount. _g_a_m_m_a_R_e_t_u_r_n Specifies a pointer to a location that is to contain a pointer to an array containing the returned gamma map. Page 2 (printed 10/3/02) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) _g_a_m_m_a_S_i_z_e_R_e_t_u_r_n Specifies a location which is to receive the size of the gamma table (i.e., the number of entries in the gamma table). _g_a_m_m_a_P_r_e_c_i_s_i_o_n_R_e_t_u_r_n Specifies a location which is to receive the precision in bits of the gamma table. For example, if each entry in the gamma table is 10 bits long, the call returns 10. _g_a_m_m_a_M_a_p_A_t_t_r_i_b_u_t_e_s A bitmask describing attributes of the gamma map. The bitmask may contain one or more of the following attributes: _X_S_G_I_V_C__G_M_A_l_p_h_a_P_r_e_s_e_n_t, or _X_S_G_I_V_C__G_M_H_a_r_d_w_a_r_e_A_p_p_r_o_x_i_m_a_t_i_o_n. See the discussion below for a more thorough treatment of attributes _r_e_q_u_e_s_t_e_d_C_o_l_o_r For queries, specifies which color component's information should be returned. Use the constants _X_S_G_I_V_C__C_O_M_P_O_N_E_N_T__R_E_D, _X_S_G_I_V_C__C_O_M_P_O_N_E_N_T__G_R_E_E_N, _X_S_G_I_V_C__C_O_M_P_O_N_E_N_T__B_L_U_E, or _X_S_G_I_V_C__C_O_M_P_O_N_E_N_T__A_L_P_H_A. The server may ignore the alpha component if the gamma map does not have an alpha component; see XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaMMMMaaaapppp. DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN GGGGaaaammmmmmmmaaaa CCCCoooorrrrrrrreeeeccccttttiiiioooonnnn aaaannnndddd SSSSeeeerrrrvvvveeeerrrr CCCCoooonnnnffffiiiigggguuuurrrraaaattttiiiioooonnnn Cathode ray tubes (CRTs) have the unfortunate characteristic that their display is non-linear: the intensity of light displayed at a pixel is not strictly proportional to the voltage supplied to the CRT at that pixel. Gamma correction is used to compensate for that non-linearity so the monitor does produce the proper intensity. A server may contain one or more gamma maps, each of which may perform an independent correction by serving as a look- up table. A gamma map has two distinguishing features: the number of entries in the table (i.e., each gamma color) and the width of each entry. These correspond to the input and output values, respectively, as each pixel is processed through the look-up table. Depending on server configuration, a channel may use one of Page 3 (printed 10/3/02) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) one or more gamma maps. Servers may assign a permanent gamma map to a channel, restrict channels to use one of a subset of all maps, permit a channel to use one of all shared maps, or some combination thereof, depending on hardware configuration. If two channels employ the same gamma map, changing the colors in that gamma map will affect both channels. FFFFuuuunnnnccccttttiiiioooonnnnssss XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyySSSSccccrrrreeeeeeeennnnGGGGaaaammmmmmmmaaaaMMMMaaaappppssss returns the number of separate gamma maps supported. For each gamma map supported, the system returns the number of entries supported. Each color component in a gamma map must support the same number of entries, different gamma maps may support different numbers of entries. Systems with no writable gamma map should return a count of zero (0). XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaMMMMaaaapppp returns information regarding a specified gamma map's configuration. The XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss8888 and XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss11116666 functions change the gamma map entries for the specified map to the specified colors, the former function loading 8-bit entries and the latter loading 16-bit entries. To load a gamma color, you pass a single array of values via _g_a_m_m_a_V_a_l_u_e and specify into which color components that array will be loaded. The _d_o_R_e_d, _d_o_G_r_e_e_n, _d_o_B_l_u_eand _d_o_A_l_p_h_a arguments indicate which components should actually be changed. If you select more than one component, each component will be loaded with the same values; you may select any one or a combination of the colors to load. N.B.: The hardware of some servers may require the server to load all components simultaneously in an encoded (packed) manner, so choosing a single color component may require the server to query the gamma table to encode the component before writing it; thus, the most efficient use of this function may be to store all color components simultaneously. All tables loaded via a single call must have the same number of entries, specified via the parameter _i_t_e_m_C_o_u_n_t. Note that the count of the number of entries you load in a table must exactly equal the length of the table (returned via the parameter _g_a_m_m_a_S_i_z_e_R_e_t_u_r_n in the function XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaMMMMaaaapppp). XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss(((()))) returns the gamma values for the specified gamma map. The number of items in the requested color component is returned in itemCountReturn. Use XXXXFFFFrrrreeeeeeee(((()))) to free the memory allocated in _g_a_m_m_a_V_a_l_u_e_R_e_t_u_r_n. Page 4 (printed 10/3/02) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) XXXXSSSSGGGGIIIIvvvvccccSSSSeeeettttCCCChhhhaaaannnnnnnneeeellllGGGGaaaammmmmmmmaaaaMMMMaaaapppp(((()))) selects the specified channel to use the specified gamma map. On server startup, each channel uses the lowest-number gamma map available to it. XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyCCCChhhhaaaannnnnnnneeeellllGGGGaaaammmmmmmmaaaaMMMMaaaapppp(((()))) returns the gamma map ID associated with the specified channel. The function XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss8888 is provided as an economy to the function XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss11116666 because it minimizes traffic between the client and X server. You should use the operation that best suits your need: for rapid animations, you may prefer the 8-bit function; for greater accuracy, the 16-bit function. SSSSeeeerrrrvvvveeeerrrr''''ssss OOOOppppeeeerrrraaaattttiiiioooonnnnssss oooonnnn CCCCoooolllloooorrrrssss DDDDuuuurrrriiiinnnngggg SSSSttttoooorrrreeee If you store a gamma map's colors using a function whose width is different than the width of the gamma map, the server will alter the values when loading the gamma hardware. This alteration occurs for each color value you specify. If you use a function whose width is larger than that of the table, the server will truncate, using only the most- signficant bits (MSBs) of your values; for example, if you use the XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss8888 function to store values into a table that contains only five bits, the server will use only the upper five MSBs of your color values, discarding the lower three bits. If you use a function whose width is narrower than the table, the server will use your stored values for the most- significants bits (MSBs), and store into the unsupplied least-signficant bits (LSBs) a copy of the most significant bits; for example, if you use the XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss8888 function to store values into a table that contains 12 bits, the server will store your values into the eight MSBs, copying the upper four bits of each of your values into each entry's LSBs. SSSSeeeerrrrvvvveeeerrrr''''ssss OOOOppppeeeerrrraaaattttiiiioooonnnnssss oooonnnn CCCCoooolllloooorrrrssss DDDDuuuurrrriiiinnnngggg QQQQuuuueeeerrrryyyy The XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss function implicitly returns 16- bit quantities, irrespective of the precision of the underlying hardware. If the gamma map's precision is less than 16 bits, the server will return the significant bits of the precision in the uppermost bits of the returned 16-bit quantity; the least significant bits of the returned quantity will contain replicated copies of the gamma map's MSBs. Page 5 (printed 10/3/02) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) This operation is similar and complementary to the actions taken during store operations. For example, if the hardware gamma map has 11 significant bits, the 16-bit value returned to the client will contain the hardware's value in bits the upper 11 bits. The most significant five bits of the hardware's value will be replicated in the lower four bits of the returned value. In general, the significant bits of the returned value may be determined via the following C-language statement (given _p_r_e_c_i_s_i_o_n as the width of the gamma entry and _g_a_m_m_a_V_a_l_u_e_R_e_t_u_r_n as the returned value): unsigned short sigBits; ... sigBits = (gammaValueReturn >> (16 - precision)); You can use the function XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss11116666 as a complementary store operation; that function expects a value with the significant bits similarly shifted into the MSBs. GGGGaaaammmmmmmmaaaa MMMMaaaapppp AAAAttttttttrrrriiiibbbbuuuutttteeeessss Some gamma maps may have certain attributes which modify their operation. The attributes of the gamma map may be retrieved by calling XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaMMMMaaaapppp. The attributes are: _X_S_G_I_V_C__G_M_A_l_p_h_a_P_r_e_s_e_n_t The gamma map has an alpha component in addition to the red, green, and blue components. _X_S_G_I_V_C__G_M_H_a_r_d_w_a_r_e_A_p_p_r_o_x_i_m_a_t_i_o_n The server hardware may use private techniques to approximate the stated size and precision of the gamma map, substituting a less thorough representation. In most cases when you load a gamma-shaped curve, the visual result will not be different from that of a gamma map which has not undergone hardware approximation. Queries of the value of the colors of this gamma map will return the values as previously stored, not of the internal approximation. The techniques used to approximate the gamma map are at the discretion of the server. _X_S_G_I_V_C__G_M_W_r_i_t_e_L_o_c_k The gamma map cannot be modified programmatically. The server hardware may have a fixed gamma map or the server does not implement alteration of this map. _X_S_G_I_V_C__G_M_R_e_a_d_L_o_c_k The gamma map cannot be queried programmatically. The Page 6 (printed 10/3/02) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss((((3333)))) server hardware may not permit readback or the server does not implement readback of this map. EEEEVVVVEEEENNNNTTTTSSSS When this control is altered, the server generates a GammaMapNotify event. RRRREEEETTTTUUUURRRRNNNNEEEEDDDD VVVVAAAALLLLUUUUEEEE XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss, XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyCCCChhhhaaaannnnnnnneeeellllGGGGaaaammmmmmmmaaaaMMMMaaaapppp, XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaMMMMaaaapppp, and XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyySSSSccccrrrreeeeeeeennnnGGGGaaaammmmmmmmaaaaMMMMaaaappppssss return TRUE if successful, FALSE upon failure. Parameter errors are reported via BadValue or BadMatch. DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS In the XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss8888(((()))) and XXXXSSSSGGGGIIIIvvvvccccSSSSttttoooorrrreeeeGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss11116666(((()))) functions, a Value error is generated if a specified pixel is not a valid index into the gamma map. If more than one pixel is in error, it is arbitrary as to which pixel is reported. A Colormap error is generated if the map id is not valid. In the XXXXSSSSGGGGIIIIvvvvccccQQQQuuuueeeerrrryyyyGGGGaaaammmmmmmmaaaaCCCCoooolllloooorrrrssss(((()))) function, a Colormap error is generated if the gamma map id is invalid. A Value error is generated if a pixel is invalid. If more than one pixel is in error, it is arbitrary as to which pixel is reported. SSSSEEEEEEEE AAAALLLLSSSSOOOO XSGIvc Page 7 (printed 10/3/02) 
