mesa xserver pixman git update 25 nov 2011

1 files changed, 741 insertions, 741 deletions

diff --git a/xorg-server/hw/xfree86/utils/gtf/gtf.c b/xorg-server/hw/xfree86/utils/gtf/gtf.c
index 840626c66..87fcb3f0e 100644
--- a/xorg-server/hw/xfree86/utils/gtf/gtf.c
+++ b/xorg-server/hw/xfree86/utils/gtf/gtf.c
@@ -1,741 +1,741 @@
-/* gtf.c  Generate mode timings using the GTF Timing Standard

- *

- * gcc gtf.c -o gtf -lm -Wall

- *

- * Copyright (c) 2001, Andy Ritger  aritger@nvidia.com

- * All rights reserved.

- * 

- * Redistribution and use in source and binary forms, with or without

- * modification, are permitted provided that the following conditions

- * are met:

- * 

- * o Redistributions of source code must retain the above copyright

- *   notice, this list of conditions and the following disclaimer.

- * o Redistributions in binary form must reproduce the above copyright

- *   notice, this list of conditions and the following disclaimer

- *   in the documentation and/or other materials provided with the

- *   distribution.

- * o Neither the name of NVIDIA nor the names of its contributors

- *   may be used to endorse or promote products derived from this

- *   software without specific prior written permission.

- *

- *

- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT

- * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

- * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL

- * THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,

- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,

- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

- * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

- * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

- * POSSIBILITY OF SUCH DAMAGE.

- *

- * 

- *

- * This program is based on the Generalized Timing Formula(GTF TM)

- * Standard Version: 1.0, Revision: 1.0

- *

- * The GTF Document contains the following Copyright information:

- *

- * Copyright (c) 1994, 1995, 1996 - Video Electronics Standards

- * Association. Duplication of this document within VESA member

- * companies for review purposes is permitted. All other rights

- * reserved.

- *

- * While every precaution has been taken in the preparation

- * of this standard, the Video Electronics Standards Association and

- * its contributors assume no responsibility for errors or omissions,

- * and make no warranties, expressed or implied, of functionality

- * of suitability for any purpose. The sample code contained within

- * this standard may be used without restriction.

- *

- * 

- *

- * The GTF EXCEL(TM) SPREADSHEET, a sample (and the definitive)

- * implementation of the GTF Timing Standard, is available at:

- *

- * ftp://ftp.vesa.org/pub/GTF/GTF_V1R1.xls

- *

- *

- *

- * This program takes a desired resolution and vertical refresh rate,

- * and computes mode timings according to the GTF Timing Standard.

- * These mode timings can then be formatted as an XServer modeline

- * or a mode description for use by fbset(8).

- *

- *

- *

- * NOTES:

- *

- * The GTF allows for computation of "margins" (the visible border

- * surrounding the addressable video); on most non-overscan type

- * systems, the margin period is zero.  I've implemented the margin

- * computations but not enabled it because 1) I don't really have

- * any experience with this, and 2) neither XServer modelines nor

- * fbset fb.modes provide an obvious way for margin timings to be

- * included in their mode descriptions (needs more investigation).

- * 

- * The GTF provides for computation of interlaced mode timings;

- * I've implemented the computations but not enabled them, yet.

- * I should probably enable and test this at some point.

- *

- * 

- *

- * TODO:

- *

- * o Add support for interlaced modes.

- *

- * o Implement the other portions of the GTF: compute mode timings

- *   given either the desired pixel clock or the desired horizontal

- *   frequency.

- *

- * o It would be nice if this were more general purpose to do things

- *   outside the scope of the GTF: like generate double scan mode

- *   timings, for example.

- *   

- * o Printing digits to the right of the decimal point when the

- *   digits are 0 annoys me.

- *

- * o Error checking.

- *

- */

-

-#ifdef HAVE_XORG_CONFIG_H

-# include <xorg-config.h>

-#endif

-

-#include <stdio.h>

-#include <stdlib.h>

-#include <string.h>

-#include <math.h>

-

-#define MARGIN_PERCENT    1.8   /* % of active vertical image                */

-#define CELL_GRAN         8.0   /* assumed character cell granularity        */

-#define MIN_PORCH         1     /* minimum front porch                       */

-#define V_SYNC_RQD        3     /* width of vsync in lines                   */

-#define H_SYNC_PERCENT    8.0   /* width of hsync as % of total line         */

-#define MIN_VSYNC_PLUS_BP 550.0 /* min time of vsync + back porch (microsec) */

-#define M                 600.0 /* blanking formula gradient                 */

-#define C                 40.0  /* blanking formula offset                   */

-#define K                 128.0 /* blanking formula scaling factor           */

-#define J                 20.0  /* blanking formula scaling factor           */

-

-/* C' and M' are part of the Blanking Duty Cycle computation */

-

-#define C_PRIME           (((C - J) * K/256.0) + J)

-#define M_PRIME           (K/256.0 * M)

-

-

-/* struct definitions */

-

-typedef struct __mode

-{

-    int hr, hss, hse, hfl;

-    int vr, vss, vse, vfl;

-    float pclk, h_freq, v_freq;

-} mode;

-

-

-typedef struct __options

-{

-    int x, y;

-    int xorgmode, fbmode;

-    float v_freq;

-} options;

-

-

-

-

-/* prototypes */

-

-void print_value(int n, char *name, float val);

-void print_xf86_mode (mode *m);

-void print_fb_mode (mode *m);

-mode *vert_refresh (int h_pixels, int v_lines, float freq,

-                    int interlaced, int margins);

-options *parse_command_line (int argc, char *argv[]);

-

-

-

-

-/*

- * print_value() - print the result of the named computation; this is

- * useful when comparing against the GTF EXCEL spreadsheet.

- */

-

-int global_verbose = 0;

-

-void print_value(int n, char *name, float val)

-{

-    if (global_verbose) {

-        printf("%2d: %-27s: %15f\n", n, name, val);

-    }

-}

-

-

-

-/* print_xf86_mode() - print the XServer modeline, given mode timings. */

-

-void print_xf86_mode (mode *m)

-{

-    printf ("\n");

-    printf ("  # %dx%d @ %.2f Hz (GTF) hsync: %.2f kHz; pclk: %.2f MHz\n",

-            m->hr, m->vr, m->v_freq, m->h_freq, m->pclk);

-    

-    printf ("  Modeline \"%dx%d_%.2f\"  %.2f"

-            "  %d %d %d %d"

-            "  %d %d %d %d"

-            "  -HSync +Vsync\n\n",

-            m->hr, m->vr, m->v_freq, m->pclk,

-            m->hr, m->hss, m->hse, m->hfl,

-            m->vr, m->vss, m->vse, m->vfl);

-    

-}

-

-

-

-/*

- * print_fb_mode() - print a mode description in fbset(8) format;

- * see the fb.modes(8) manpage.  The timing description used in

- * this is rather odd; they use "left and right margin" to refer

- * to the portion of the hblank before and after the sync pulse

- * by conceptually wrapping the portion of the blank after the pulse

- * to infront of the visible region; ie:

- * 

- *

- * Timing description I'm accustomed to:

- *

- *

- *

- *     <--------1--------> <--2--> <--3--> <--4-->

- *                                _________

- *    |-------------------|_______|       |_______

- *

- *                        R       SS      SE     FL

- *       

- * 1: visible image

- * 2: blank before sync (aka front porch)

- * 3: sync pulse

- * 4: blank after sync (aka back porch)

- * R: Resolution

- * SS: Sync Start

- * SE: Sync End

- * FL: Frame Length

- *

- *

- * But the fb.modes format is:

- *

- *

- *    <--4--> <--------1--------> <--2--> <--3--> 

- *                                       _________

- *    _______|-------------------|_______|       |

- *  

- * The fb.modes(8) manpage refers to <4> and <2> as the left and

- * right "margin" (as well as upper and lower margin in the vertical

- * direction) -- note that this has nothing to do with the term

- * "margin" used in the GTF Timing Standard.

- *

- * XXX always prints the 32 bit mode -- should I provide a command

- * line option to specify the bpp?  It's simple enough for a user

- * to edit the mode description after it's generated.

- */

-

-void print_fb_mode (mode *m)

-{

-    printf ("\n");

-    printf ("mode \"%dx%d %.2fHz 32bit (GTF)\"\n",

-            m->hr, m->vr, m->v_freq);

-    printf ("    # PCLK: %.2f MHz, H: %.2f kHz, V: %.2f Hz\n",

-            m->pclk, m->h_freq, m->v_freq);

-    printf ("    geometry %d %d %d %d 32\n",

-            m->hr, m->vr, m->hr, m->vr);

-    printf ("    timings %d %d %d %d %d %d %d\n",

-            (int) rint(1000000.0/m->pclk),/* pixclock in picoseconds */

-            m->hfl - m->hse,              /* left margin (in pixels) */

-            m->hss - m->hr,               /* right margin (in pixels) */

-            m->vfl - m->vse,              /* upper margin (in pixel lines) */

-            m->vss - m->vr,               /* lower margin (in pixel lines) */

-            m->hse - m->hss,              /* horizontal sync length (pixels) */

-            m->vse - m->vss);             /* vert sync length (pixel lines) */

-    printf ("    hsync low\n");

-    printf ("    vsync high\n");

-    printf ("endmode\n\n");

-    

-}

-

-

-

-

-/*

- * vert_refresh() - as defined by the GTF Timing Standard, compute the

- * Stage 1 Parameters using the vertical refresh frequency.  In other

- * words: input a desired resolution and desired refresh rate, and

- * output the GTF mode timings.

- *

- * XXX All the code is in place to compute interlaced modes, but I don't

- * feel like testing it right now.

- *

- * XXX margin computations are implemented but not tested (nor used by

- * XServer of fbset mode descriptions, from what I can tell).

- */

-

-mode *vert_refresh (int h_pixels, int v_lines, float freq,

-                    int interlaced, int margins)

-{

-    float h_pixels_rnd;

-    float v_lines_rnd;

-    float v_field_rate_rqd;

-    float top_margin;

-    float bottom_margin;

-    float interlace;

-    float h_period_est;

-    float vsync_plus_bp;

-    float v_back_porch;

-    float total_v_lines;

-    float v_field_rate_est;

-    float h_period;

-    float v_field_rate;

-    float v_frame_rate;

-    float left_margin;

-    float right_margin;

-    float total_active_pixels;

-    float ideal_duty_cycle;

-    float h_blank;

-    float total_pixels;

-    float pixel_freq;

-    float h_freq;

-

-    float h_sync;

-    float h_front_porch;

-    float v_odd_front_porch_lines;

-

-    mode *m = (mode*) malloc (sizeof (mode));

-    

-    

-    /*  1. In order to give correct results, the number of horizontal

-     *  pixels requested is first processed to ensure that it is divisible

-     *  by the character size, by rounding it to the nearest character

-     *  cell boundary:

-     *

-     *  [H PIXELS RND] = ((ROUND([H PIXELS]/[CELL GRAN RND],0))*[CELLGRAN RND])

-     */

-    

-    h_pixels_rnd = rint((float) h_pixels / CELL_GRAN) * CELL_GRAN;

-    

-    print_value(1, "[H PIXELS RND]", h_pixels_rnd);

-

-    

-    /*  2. If interlace is requested, the number of vertical lines assumed

-     *  by the calculation must be halved, as the computation calculates

-     *  the number of vertical lines per field. In either case, the

-     *  number of lines is rounded to the nearest integer.

-     *   

-     *  [V LINES RND] = IF([INT RQD?]="y", ROUND([V LINES]/2,0),

-     *                                     ROUND([V LINES],0))

-     */

-

-    v_lines_rnd = interlaced ?

-            rint((float) v_lines) / 2.0 :

-            rint((float) v_lines);

-    

-    print_value(2, "[V LINES RND]", v_lines_rnd);

-    

-    

-    /*  3. Find the frame rate required:

-     *

-     *  [V FIELD RATE RQD] = IF([INT RQD?]="y", [I/P FREQ RQD]*2,

-     *                                          [I/P FREQ RQD])

-     */

-

-    v_field_rate_rqd = interlaced ? (freq * 2.0) : (freq);

-

-    print_value(3, "[V FIELD RATE RQD]", v_field_rate_rqd);

-    

-

-    /*  4. Find number of lines in Top margin:

-     *

-     *  [TOP MARGIN (LINES)] = IF([MARGINS RQD?]="Y",

-     *          ROUND(([MARGIN%]/100*[V LINES RND]),0),

-     *          0)

-     */

-

-    top_margin = margins ? rint(MARGIN_PERCENT / 100.0 * v_lines_rnd) : (0.0);

-

-    print_value(4, "[TOP MARGIN (LINES)]", top_margin);

-    

-

-    /*  5. Find number of lines in Bottom margin:

-     *

-     *  [BOT MARGIN (LINES)] = IF([MARGINS RQD?]="Y",

-     *          ROUND(([MARGIN%]/100*[V LINES RND]),0),

-     *          0)

-     */

-

-    bottom_margin = margins ? rint(MARGIN_PERCENT/100.0 * v_lines_rnd) : (0.0);

-

-    print_value(5, "[BOT MARGIN (LINES)]", bottom_margin);

-

-    

-    /*  6. If interlace is required, then set variable [INTERLACE]=0.5:

-     *   

-     *  [INTERLACE]=(IF([INT RQD?]="y",0.5,0))

-     */

-

-    interlace = interlaced ? 0.5 : 0.0;

-

-    print_value(6, "[INTERLACE]", interlace);

-    

-

-    /*  7. Estimate the Horizontal period

-     *

-     *  [H PERIOD EST] = ((1/[V FIELD RATE RQD]) - [MIN VSYNC+BP]/1000000) /

-     *                    ([V LINES RND] + (2*[TOP MARGIN (LINES)]) +

-     *                     [MIN PORCH RND]+[INTERLACE]) * 1000000

-     */

-

-    h_period_est = (((1.0/v_field_rate_rqd) - (MIN_VSYNC_PLUS_BP/1000000.0))

-                    / (v_lines_rnd + (2*top_margin) + MIN_PORCH + interlace)

-                    * 1000000.0);

-

-    print_value(7, "[H PERIOD EST]", h_period_est);

-    

-

-    /*  8. Find the number of lines in V sync + back porch:

-     *

-     *  [V SYNC+BP] = ROUND(([MIN VSYNC+BP]/[H PERIOD EST]),0)

-     */

-

-    vsync_plus_bp = rint(MIN_VSYNC_PLUS_BP/h_period_est);

-

-    print_value(8, "[V SYNC+BP]", vsync_plus_bp);

-    

-    

-    /*  9. Find the number of lines in V back porch alone:

-     *

-     *  [V BACK PORCH] = [V SYNC+BP] - [V SYNC RND]

-     *

-     *  XXX is "[V SYNC RND]" a typo? should be [V SYNC RQD]?

-     */

-    

-    v_back_porch = vsync_plus_bp - V_SYNC_RQD;

-    

-    print_value(9, "[V BACK PORCH]", v_back_porch);

-    

-

-    /*  10. Find the total number of lines in Vertical field period:

-     *

-     *  [TOTAL V LINES] = [V LINES RND] + [TOP MARGIN (LINES)] +

-     *                    [BOT MARGIN (LINES)] + [V SYNC+BP] + [INTERLACE] +

-     *                    [MIN PORCH RND]

-     */

-

-    total_v_lines = v_lines_rnd + top_margin + bottom_margin + vsync_plus_bp +

-        interlace + MIN_PORCH;

-    

-    print_value(10, "[TOTAL V LINES]", total_v_lines);

-    

-

-    /*  11. Estimate the Vertical field frequency:

-     *

-     *  [V FIELD RATE EST] = 1 / [H PERIOD EST] / [TOTAL V LINES] * 1000000

-     */

-

-    v_field_rate_est = 1.0 / h_period_est / total_v_lines * 1000000.0;

-    

-    print_value(11, "[V FIELD RATE EST]", v_field_rate_est);

-    

-

-    /*  12. Find the actual horizontal period:

-     *

-     *  [H PERIOD] = [H PERIOD EST] / ([V FIELD RATE RQD] / [V FIELD RATE EST])

-     */

-

-    h_period = h_period_est / (v_field_rate_rqd / v_field_rate_est);

-    

-    print_value(12, "[H PERIOD]", h_period);

-    

-

-    /*  13. Find the actual Vertical field frequency:

-     *

-     *  [V FIELD RATE] = 1 / [H PERIOD] / [TOTAL V LINES] * 1000000

-     */

-

-    v_field_rate = 1.0 / h_period / total_v_lines * 1000000.0;

-

-    print_value(13, "[V FIELD RATE]", v_field_rate);

-    

-

-    /*  14. Find the Vertical frame frequency:

-     *

-     *  [V FRAME RATE] = (IF([INT RQD?]="y", [V FIELD RATE]/2, [V FIELD RATE]))

-     */

-

-    v_frame_rate = interlaced ? v_field_rate / 2.0 : v_field_rate;

-

-    print_value(14, "[V FRAME RATE]", v_frame_rate);

-    

-

-    /*  15. Find number of pixels in left margin:

-     *

-     *  [LEFT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",

-     *          (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /

-     *                   [CELL GRAN RND]),0)) * [CELL GRAN RND],

-     *          0))

-     */

-

-    left_margin = margins ?

-        rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN :

-        0.0;

-    

-    print_value(15, "[LEFT MARGIN (PIXELS)]", left_margin);

-    

-

-    /*  16. Find number of pixels in right margin:

-     *

-     *  [RIGHT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",

-     *          (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /

-     *                   [CELL GRAN RND]),0)) * [CELL GRAN RND],

-     *          0))

-     */

-    

-    right_margin = margins ?

-        rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN :

-        0.0;

-    

-    print_value(16, "[RIGHT MARGIN (PIXELS)]", right_margin);

-    

-

-    /*  17. Find total number of active pixels in image and left and right

-     *  margins:

-     *

-     *  [TOTAL ACTIVE PIXELS] = [H PIXELS RND] + [LEFT MARGIN (PIXELS)] +

-     *                          [RIGHT MARGIN (PIXELS)]

-     */

-

-    total_active_pixels = h_pixels_rnd + left_margin + right_margin;

-    

-    print_value(17, "[TOTAL ACTIVE PIXELS]", total_active_pixels);

-    

-    

-    /*  18. Find the ideal blanking duty cycle from the blanking duty cycle

-     *  equation:

-     *

-     *  [IDEAL DUTY CYCLE] = [C'] - ([M']*[H PERIOD]/1000)

-     */

-

-    ideal_duty_cycle = C_PRIME - (M_PRIME * h_period / 1000.0);

-    

-    print_value(18, "[IDEAL DUTY CYCLE]", ideal_duty_cycle);

-    

-

-    /*  19. Find the number of pixels in the blanking time to the nearest

-     *  double character cell:

-     *

-     *  [H BLANK (PIXELS)] = (ROUND(([TOTAL ACTIVE PIXELS] *

-     *                               [IDEAL DUTY CYCLE] /

-     *                               (100-[IDEAL DUTY CYCLE]) /

-     *                               (2*[CELL GRAN RND])), 0))

-     *                       * (2*[CELL GRAN RND])

-     */

-

-    h_blank = rint(total_active_pixels *

-                   ideal_duty_cycle /

-                   (100.0 - ideal_duty_cycle) /

-                   (2.0 * CELL_GRAN)) * (2.0 * CELL_GRAN);

-    

-    print_value(19, "[H BLANK (PIXELS)]", h_blank);

-    

-

-    /*  20. Find total number of pixels:

-     *

-     *  [TOTAL PIXELS] = [TOTAL ACTIVE PIXELS] + [H BLANK (PIXELS)]

-     */

-

-    total_pixels = total_active_pixels + h_blank;

-    

-    print_value(20, "[TOTAL PIXELS]", total_pixels);

-    

-

-    /*  21. Find pixel clock frequency:

-     *

-     *  [PIXEL FREQ] = [TOTAL PIXELS] / [H PERIOD]

-     */

-    

-    pixel_freq = total_pixels / h_period;

-    

-    print_value(21, "[PIXEL FREQ]", pixel_freq);

-    

-

-    /*  22. Find horizontal frequency:

-     *

-     *  [H FREQ] = 1000 / [H PERIOD]

-     */

-

-    h_freq = 1000.0 / h_period;

-    

-    print_value(22, "[H FREQ]", h_freq);

-    

-

-

-    /* Stage 1 computations are now complete; I should really pass

-       the results to another function and do the Stage 2

-       computations, but I only need a few more values so I'll just

-       append the computations here for now */

-

-    

-

-    /*  17. Find the number of pixels in the horizontal sync period:

-     *

-     *  [H SYNC (PIXELS)] =(ROUND(([H SYNC%] / 100 * [TOTAL PIXELS] /

-     *                             [CELL GRAN RND]),0))*[CELL GRAN RND]

-     */

-

-    h_sync = rint(H_SYNC_PERCENT/100.0 * total_pixels / CELL_GRAN) * CELL_GRAN;

-

-    print_value(17, "[H SYNC (PIXELS)]", h_sync);

-    

-

-    /*  18. Find the number of pixels in the horizontal front porch period:

-     *

-     *  [H FRONT PORCH (PIXELS)] = ([H BLANK (PIXELS)]/2)-[H SYNC (PIXELS)]

-     */

-

-    h_front_porch = (h_blank / 2.0) - h_sync;

-

-    print_value(18, "[H FRONT PORCH (PIXELS)]", h_front_porch);

-    

-    

-    /*  36. Find the number of lines in the odd front porch period:

-     *

-     *  [V ODD FRONT PORCH(LINES)]=([MIN PORCH RND]+[INTERLACE])

-     */

-    

-    v_odd_front_porch_lines = MIN_PORCH + interlace;

-    

-    print_value(36, "[V ODD FRONT PORCH(LINES)]", v_odd_front_porch_lines);

-    

-

-    /* finally, pack the results in the mode struct */

-    

-    m->hr  = (int) (h_pixels_rnd);

-    m->hss = (int) (h_pixels_rnd + h_front_porch);

-    m->hse = (int) (h_pixels_rnd + h_front_porch + h_sync);

-    m->hfl = (int) (total_pixels);

-

-    m->vr  = (int) (v_lines_rnd);

-    m->vss = (int) (v_lines_rnd + v_odd_front_porch_lines);

-    m->vse = (int) (int) (v_lines_rnd + v_odd_front_porch_lines + V_SYNC_RQD);

-    m->vfl = (int) (total_v_lines);

-

-    m->pclk   = pixel_freq;

-    m->h_freq = h_freq;

-    m->v_freq = freq;

-

-    return m;

-    

-}

-

-

-

-

-/*

- * parse_command_line() - parse the command line and return an

- * alloced structure containing the results.  On error print usage

- * and return NULL.

- */ 

-

-options *parse_command_line (int argc, char *argv[])

-{

-    int n;

-

-    options *o = (options *) calloc (1, sizeof (options));

-

-    if (argc < 4) goto bad_option;

-

-    o->x = atoi (argv[1]);

-    o->y = atoi (argv[2]);

-    o->v_freq = atof (argv[3]);

-

-    /* XXX should check for errors in the above */

-    

-    n = 4;

-

-    while (n < argc) {

-        if ((strcmp (argv[n], "-v") == 0) ||

-            (strcmp (argv[n], "--verbose") == 0)) {

-            global_verbose = 1;

-        } else if ((strcmp (argv[n], "-f") == 0) ||

-                   (strcmp (argv[n], "--fbmode") == 0)) {

-            o->fbmode = 1;

-        } else if ((strcmp (argv[n], "-x") == 0) ||

-		   (strcmp (argv[n], "--xorgmode") == 0) ||

-                   (strcmp (argv[n], "--xf86mode") == 0)) {

-            o->xorgmode = 1;

-        } else {

-            goto bad_option;

-        }

-        

-        n++;

-    }

-

-    /* if neither xorgmode nor fbmode were requested, default to

-       xorgmode */

-

-    if (!o->fbmode && !o->xorgmode) o->xorgmode = 1;

-    

-    return o;

-    

- bad_option:

-

-    fprintf (stderr, "\n");

-    fprintf (stderr, "usage: %s x y refresh [-v|--verbose] "

-             "[-f|--fbmode] [-x|--xorgmode]\n", argv[0]);

-

-    fprintf (stderr, "\n");

-    

-    fprintf (stderr, "            x : the desired horizontal "

-             "resolution (required)\n");

-    fprintf (stderr, "            y : the desired vertical "

-             "resolution (required)\n");

-    fprintf (stderr, "      refresh : the desired refresh "

-             "rate (required)\n");

-    fprintf (stderr, " -v|--verbose : enable verbose printouts "

-             "(traces each step of the computation)\n");

-    fprintf (stderr, "  -f|--fbmode : output an fbset(8)-style mode "

-             "description\n");

-    fprintf (stderr, " -x|--xorgmode : output an "__XSERVERNAME__"-style mode "

-             "description (this is the default\n"

-             "                if no mode description is requested)\n");

-    

-    fprintf (stderr, "\n");

-    

-    free (o);

-    return NULL;

-

-}

-

-

-

-int main (int argc, char *argv[])

-{

-    mode *m;

-    options *o;

-

-    o = parse_command_line (argc, argv);

-    if (!o) exit (1);

-    

-    m = vert_refresh (o->x, o->y, o->v_freq, 0, 0);

-    if (!m) exit (1);

-

-    if (o->xorgmode)

-        print_xf86_mode(m);

-    

-    if (o->fbmode)

-        print_fb_mode(m);

-    

-    return 0;

-    

-}

+/* gtf.c  Generate mode timings using the GTF Timing Standard
+ *
+ * gcc gtf.c -o gtf -lm -Wall
+ *
+ * Copyright (c) 2001, Andy Ritger  aritger@nvidia.com
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ * o Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * o Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer
+ *   in the documentation and/or other materials provided with the
+ *   distribution.
+ * o Neither the name of NVIDIA nor the names of its contributors
+ *   may be used to endorse or promote products derived from this
+ *   software without specific prior written permission.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
+ * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * 
+ *
+ * This program is based on the Generalized Timing Formula(GTF TM)
+ * Standard Version: 1.0, Revision: 1.0
+ *
+ * The GTF Document contains the following Copyright information:
+ *
+ * Copyright (c) 1994, 1995, 1996 - Video Electronics Standards
+ * Association. Duplication of this document within VESA member
+ * companies for review purposes is permitted. All other rights
+ * reserved.
+ *
+ * While every precaution has been taken in the preparation
+ * of this standard, the Video Electronics Standards Association and
+ * its contributors assume no responsibility for errors or omissions,
+ * and make no warranties, expressed or implied, of functionality
+ * of suitability for any purpose. The sample code contained within
+ * this standard may be used without restriction.
+ *
+ * 
+ *
+ * The GTF EXCEL(TM) SPREADSHEET, a sample (and the definitive)
+ * implementation of the GTF Timing Standard, is available at:
+ *
+ * ftp://ftp.vesa.org/pub/GTF/GTF_V1R1.xls
+ *
+ *
+ *
+ * This program takes a desired resolution and vertical refresh rate,
+ * and computes mode timings according to the GTF Timing Standard.
+ * These mode timings can then be formatted as an XServer modeline
+ * or a mode description for use by fbset(8).
+ *
+ *
+ *
+ * NOTES:
+ *
+ * The GTF allows for computation of "margins" (the visible border
+ * surrounding the addressable video); on most non-overscan type
+ * systems, the margin period is zero.  I've implemented the margin
+ * computations but not enabled it because 1) I don't really have
+ * any experience with this, and 2) neither XServer modelines nor
+ * fbset fb.modes provide an obvious way for margin timings to be
+ * included in their mode descriptions (needs more investigation).
+ * 
+ * The GTF provides for computation of interlaced mode timings;
+ * I've implemented the computations but not enabled them, yet.
+ * I should probably enable and test this at some point.
+ *
+ * 
+ *
+ * TODO:
+ *
+ * o Add support for interlaced modes.
+ *
+ * o Implement the other portions of the GTF: compute mode timings
+ *   given either the desired pixel clock or the desired horizontal
+ *   frequency.
+ *
+ * o It would be nice if this were more general purpose to do things
+ *   outside the scope of the GTF: like generate double scan mode
+ *   timings, for example.
+ *   
+ * o Printing digits to the right of the decimal point when the
+ *   digits are 0 annoys me.
+ *
+ * o Error checking.
+ *
+ */
+
+#ifdef HAVE_XORG_CONFIG_H
+# include <xorg-config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+
+#define MARGIN_PERCENT    1.8   /* % of active vertical image                */
+#define CELL_GRAN         8.0   /* assumed character cell granularity        */
+#define MIN_PORCH         1     /* minimum front porch                       */
+#define V_SYNC_RQD        3     /* width of vsync in lines                   */
+#define H_SYNC_PERCENT    8.0   /* width of hsync as % of total line         */
+#define MIN_VSYNC_PLUS_BP 550.0 /* min time of vsync + back porch (microsec) */
+#define M                 600.0 /* blanking formula gradient                 */
+#define C                 40.0  /* blanking formula offset                   */
+#define K                 128.0 /* blanking formula scaling factor           */
+#define J                 20.0  /* blanking formula scaling factor           */
+
+/* C' and M' are part of the Blanking Duty Cycle computation */
+
+#define C_PRIME           (((C - J) * K/256.0) + J)
+#define M_PRIME           (K/256.0 * M)
+
+
+/* struct definitions */
+
+typedef struct __mode
+{
+    int hr, hss, hse, hfl;
+    int vr, vss, vse, vfl;
+    float pclk, h_freq, v_freq;
+} mode;
+
+
+typedef struct __options
+{
+    int x, y;
+    int xorgmode, fbmode;
+    float v_freq;
+} options;
+
+
+
+
+/* prototypes */
+
+void print_value(int n, const char *name, float val);
+void print_xf86_mode (mode *m);
+void print_fb_mode (mode *m);
+mode *vert_refresh (int h_pixels, int v_lines, float freq,
+                    int interlaced, int margins);
+options *parse_command_line (int argc, char *argv[]);
+
+
+
+
+/*
+ * print_value() - print the result of the named computation; this is
+ * useful when comparing against the GTF EXCEL spreadsheet.
+ */
+
+int global_verbose = 0;
+
+void print_value(int n, const char *name, float val)
+{
+    if (global_verbose) {
+        printf("%2d: %-27s: %15f\n", n, name, val);
+    }
+}
+
+
+
+/* print_xf86_mode() - print the XServer modeline, given mode timings. */
+
+void print_xf86_mode (mode *m)
+{
+    printf ("\n");
+    printf ("  # %dx%d @ %.2f Hz (GTF) hsync: %.2f kHz; pclk: %.2f MHz\n",
+            m->hr, m->vr, m->v_freq, m->h_freq, m->pclk);
+    
+    printf ("  Modeline \"%dx%d_%.2f\"  %.2f"
+            "  %d %d %d %d"
+            "  %d %d %d %d"
+            "  -HSync +Vsync\n\n",
+            m->hr, m->vr, m->v_freq, m->pclk,
+            m->hr, m->hss, m->hse, m->hfl,
+            m->vr, m->vss, m->vse, m->vfl);
+    
+}
+
+
+
+/*
+ * print_fb_mode() - print a mode description in fbset(8) format;
+ * see the fb.modes(8) manpage.  The timing description used in
+ * this is rather odd; they use "left and right margin" to refer
+ * to the portion of the hblank before and after the sync pulse
+ * by conceptually wrapping the portion of the blank after the pulse
+ * to infront of the visible region; ie:
+ * 
+ *
+ * Timing description I'm accustomed to:
+ *
+ *
+ *
+ *     <--------1--------> <--2--> <--3--> <--4-->
+ *                                _________
+ *    |-------------------|_______|       |_______
+ *
+ *                        R       SS      SE     FL
+ *       
+ * 1: visible image
+ * 2: blank before sync (aka front porch)
+ * 3: sync pulse
+ * 4: blank after sync (aka back porch)
+ * R: Resolution
+ * SS: Sync Start
+ * SE: Sync End
+ * FL: Frame Length
+ *
+ *
+ * But the fb.modes format is:
+ *
+ *
+ *    <--4--> <--------1--------> <--2--> <--3--> 
+ *                                       _________
+ *    _______|-------------------|_______|       |
+ *  
+ * The fb.modes(8) manpage refers to <4> and <2> as the left and
+ * right "margin" (as well as upper and lower margin in the vertical
+ * direction) -- note that this has nothing to do with the term
+ * "margin" used in the GTF Timing Standard.
+ *
+ * XXX always prints the 32 bit mode -- should I provide a command
+ * line option to specify the bpp?  It's simple enough for a user
+ * to edit the mode description after it's generated.
+ */
+
+void print_fb_mode (mode *m)
+{
+    printf ("\n");
+    printf ("mode \"%dx%d %.2fHz 32bit (GTF)\"\n",
+            m->hr, m->vr, m->v_freq);
+    printf ("    # PCLK: %.2f MHz, H: %.2f kHz, V: %.2f Hz\n",
+            m->pclk, m->h_freq, m->v_freq);
+    printf ("    geometry %d %d %d %d 32\n",
+            m->hr, m->vr, m->hr, m->vr);
+    printf ("    timings %d %d %d %d %d %d %d\n",
+            (int) rint(1000000.0/m->pclk),/* pixclock in picoseconds */
+            m->hfl - m->hse,              /* left margin (in pixels) */
+            m->hss - m->hr,               /* right margin (in pixels) */
+            m->vfl - m->vse,              /* upper margin (in pixel lines) */
+            m->vss - m->vr,               /* lower margin (in pixel lines) */
+            m->hse - m->hss,              /* horizontal sync length (pixels) */
+            m->vse - m->vss);             /* vert sync length (pixel lines) */
+    printf ("    hsync low\n");
+    printf ("    vsync high\n");
+    printf ("endmode\n\n");
+    
+}
+
+
+
+
+/*
+ * vert_refresh() - as defined by the GTF Timing Standard, compute the
+ * Stage 1 Parameters using the vertical refresh frequency.  In other
+ * words: input a desired resolution and desired refresh rate, and
+ * output the GTF mode timings.
+ *
+ * XXX All the code is in place to compute interlaced modes, but I don't
+ * feel like testing it right now.
+ *
+ * XXX margin computations are implemented but not tested (nor used by
+ * XServer of fbset mode descriptions, from what I can tell).
+ */
+
+mode *vert_refresh (int h_pixels, int v_lines, float freq,
+                    int interlaced, int margins)
+{
+    float h_pixels_rnd;
+    float v_lines_rnd;
+    float v_field_rate_rqd;
+    float top_margin;
+    float bottom_margin;
+    float interlace;
+    float h_period_est;
+    float vsync_plus_bp;
+    float v_back_porch;
+    float total_v_lines;
+    float v_field_rate_est;
+    float h_period;
+    float v_field_rate;
+    float v_frame_rate;
+    float left_margin;
+    float right_margin;
+    float total_active_pixels;
+    float ideal_duty_cycle;
+    float h_blank;
+    float total_pixels;
+    float pixel_freq;
+    float h_freq;
+
+    float h_sync;
+    float h_front_porch;
+    float v_odd_front_porch_lines;
+
+    mode *m = (mode*) malloc (sizeof (mode));
+    
+    
+    /*  1. In order to give correct results, the number of horizontal
+     *  pixels requested is first processed to ensure that it is divisible
+     *  by the character size, by rounding it to the nearest character
+     *  cell boundary:
+     *
+     *  [H PIXELS RND] = ((ROUND([H PIXELS]/[CELL GRAN RND],0))*[CELLGRAN RND])
+     */
+    
+    h_pixels_rnd = rint((float) h_pixels / CELL_GRAN) * CELL_GRAN;
+    
+    print_value(1, "[H PIXELS RND]", h_pixels_rnd);
+
+    
+    /*  2. If interlace is requested, the number of vertical lines assumed
+     *  by the calculation must be halved, as the computation calculates
+     *  the number of vertical lines per field. In either case, the
+     *  number of lines is rounded to the nearest integer.
+     *   
+     *  [V LINES RND] = IF([INT RQD?]="y", ROUND([V LINES]/2,0),
+     *                                     ROUND([V LINES],0))
+     */
+
+    v_lines_rnd = interlaced ?
+            rint((float) v_lines) / 2.0 :
+            rint((float) v_lines);
+    
+    print_value(2, "[V LINES RND]", v_lines_rnd);
+    
+    
+    /*  3. Find the frame rate required:
+     *
+     *  [V FIELD RATE RQD] = IF([INT RQD?]="y", [I/P FREQ RQD]*2,
+     *                                          [I/P FREQ RQD])
+     */
+
+    v_field_rate_rqd = interlaced ? (freq * 2.0) : (freq);
+
+    print_value(3, "[V FIELD RATE RQD]", v_field_rate_rqd);
+    
+
+    /*  4. Find number of lines in Top margin:
+     *
+     *  [TOP MARGIN (LINES)] = IF([MARGINS RQD?]="Y",
+     *          ROUND(([MARGIN%]/100*[V LINES RND]),0),
+     *          0)
+     */
+
+    top_margin = margins ? rint(MARGIN_PERCENT / 100.0 * v_lines_rnd) : (0.0);
+
+    print_value(4, "[TOP MARGIN (LINES)]", top_margin);
+    
+
+    /*  5. Find number of lines in Bottom margin:
+     *
+     *  [BOT MARGIN (LINES)] = IF([MARGINS RQD?]="Y",
+     *          ROUND(([MARGIN%]/100*[V LINES RND]),0),
+     *          0)
+     */
+
+    bottom_margin = margins ? rint(MARGIN_PERCENT/100.0 * v_lines_rnd) : (0.0);
+
+    print_value(5, "[BOT MARGIN (LINES)]", bottom_margin);
+
+    
+    /*  6. If interlace is required, then set variable [INTERLACE]=0.5:
+     *   
+     *  [INTERLACE]=(IF([INT RQD?]="y",0.5,0))
+     */
+
+    interlace = interlaced ? 0.5 : 0.0;
+
+    print_value(6, "[INTERLACE]", interlace);
+    
+
+    /*  7. Estimate the Horizontal period
+     *
+     *  [H PERIOD EST] = ((1/[V FIELD RATE RQD]) - [MIN VSYNC+BP]/1000000) /
+     *                    ([V LINES RND] + (2*[TOP MARGIN (LINES)]) +
+     *                     [MIN PORCH RND]+[INTERLACE]) * 1000000
+     */
+
+    h_period_est = (((1.0/v_field_rate_rqd) - (MIN_VSYNC_PLUS_BP/1000000.0))
+                    / (v_lines_rnd + (2*top_margin) + MIN_PORCH + interlace)
+                    * 1000000.0);
+
+    print_value(7, "[H PERIOD EST]", h_period_est);
+    
+
+    /*  8. Find the number of lines in V sync + back porch:
+     *
+     *  [V SYNC+BP] = ROUND(([MIN VSYNC+BP]/[H PERIOD EST]),0)
+     */
+
+    vsync_plus_bp = rint(MIN_VSYNC_PLUS_BP/h_period_est);
+
+    print_value(8, "[V SYNC+BP]", vsync_plus_bp);
+    
+    
+    /*  9. Find the number of lines in V back porch alone:
+     *
+     *  [V BACK PORCH] = [V SYNC+BP] - [V SYNC RND]
+     *
+     *  XXX is "[V SYNC RND]" a typo? should be [V SYNC RQD]?
+     */
+    
+    v_back_porch = vsync_plus_bp - V_SYNC_RQD;
+    
+    print_value(9, "[V BACK PORCH]", v_back_porch);
+    
+
+    /*  10. Find the total number of lines in Vertical field period:
+     *
+     *  [TOTAL V LINES] = [V LINES RND] + [TOP MARGIN (LINES)] +
+     *                    [BOT MARGIN (LINES)] + [V SYNC+BP] + [INTERLACE] +
+     *                    [MIN PORCH RND]
+     */
+
+    total_v_lines = v_lines_rnd + top_margin + bottom_margin + vsync_plus_bp +
+        interlace + MIN_PORCH;
+    
+    print_value(10, "[TOTAL V LINES]", total_v_lines);
+    
+
+    /*  11. Estimate the Vertical field frequency:
+     *
+     *  [V FIELD RATE EST] = 1 / [H PERIOD EST] / [TOTAL V LINES] * 1000000
+     */
+
+    v_field_rate_est = 1.0 / h_period_est / total_v_lines * 1000000.0;
+    
+    print_value(11, "[V FIELD RATE EST]", v_field_rate_est);
+    
+
+    /*  12. Find the actual horizontal period:
+     *
+     *  [H PERIOD] = [H PERIOD EST] / ([V FIELD RATE RQD] / [V FIELD RATE EST])
+     */
+
+    h_period = h_period_est / (v_field_rate_rqd / v_field_rate_est);
+    
+    print_value(12, "[H PERIOD]", h_period);
+    
+
+    /*  13. Find the actual Vertical field frequency:
+     *
+     *  [V FIELD RATE] = 1 / [H PERIOD] / [TOTAL V LINES] * 1000000
+     */
+
+    v_field_rate = 1.0 / h_period / total_v_lines * 1000000.0;
+
+    print_value(13, "[V FIELD RATE]", v_field_rate);
+    
+
+    /*  14. Find the Vertical frame frequency:
+     *
+     *  [V FRAME RATE] = (IF([INT RQD?]="y", [V FIELD RATE]/2, [V FIELD RATE]))
+     */
+
+    v_frame_rate = interlaced ? v_field_rate / 2.0 : v_field_rate;
+
+    print_value(14, "[V FRAME RATE]", v_frame_rate);
+    
+
+    /*  15. Find number of pixels in left margin:
+     *
+     *  [LEFT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",
+     *          (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /
+     *                   [CELL GRAN RND]),0)) * [CELL GRAN RND],
+     *          0))
+     */
+
+    left_margin = margins ?
+        rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN :
+        0.0;
+    
+    print_value(15, "[LEFT MARGIN (PIXELS)]", left_margin);
+    
+
+    /*  16. Find number of pixels in right margin:
+     *
+     *  [RIGHT MARGIN (PIXELS)] = (IF( [MARGINS RQD?]="Y",
+     *          (ROUND( ([H PIXELS RND] * [MARGIN%] / 100 /
+     *                   [CELL GRAN RND]),0)) * [CELL GRAN RND],
+     *          0))
+     */
+    
+    right_margin = margins ?
+        rint(h_pixels_rnd * MARGIN_PERCENT / 100.0 / CELL_GRAN) * CELL_GRAN :
+        0.0;
+    
+    print_value(16, "[RIGHT MARGIN (PIXELS)]", right_margin);
+    
+
+    /*  17. Find total number of active pixels in image and left and right
+     *  margins:
+     *
+     *  [TOTAL ACTIVE PIXELS] = [H PIXELS RND] + [LEFT MARGIN (PIXELS)] +
+     *                          [RIGHT MARGIN (PIXELS)]
+     */
+
+    total_active_pixels = h_pixels_rnd + left_margin + right_margin;
+    
+    print_value(17, "[TOTAL ACTIVE PIXELS]", total_active_pixels);
+    
+    
+    /*  18. Find the ideal blanking duty cycle from the blanking duty cycle
+     *  equation:
+     *
+     *  [IDEAL DUTY CYCLE] = [C'] - ([M']*[H PERIOD]/1000)
+     */
+
+    ideal_duty_cycle = C_PRIME - (M_PRIME * h_period / 1000.0);
+    
+    print_value(18, "[IDEAL DUTY CYCLE]", ideal_duty_cycle);
+    
+
+    /*  19. Find the number of pixels in the blanking time to the nearest
+     *  double character cell:
+     *
+     *  [H BLANK (PIXELS)] = (ROUND(([TOTAL ACTIVE PIXELS] *
+     *                               [IDEAL DUTY CYCLE] /
+     *                               (100-[IDEAL DUTY CYCLE]) /
+     *                               (2*[CELL GRAN RND])), 0))
+     *                       * (2*[CELL GRAN RND])
+     */
+
+    h_blank = rint(total_active_pixels *
+                   ideal_duty_cycle /
+                   (100.0 - ideal_duty_cycle) /
+                   (2.0 * CELL_GRAN)) * (2.0 * CELL_GRAN);
+    
+    print_value(19, "[H BLANK (PIXELS)]", h_blank);
+    
+
+    /*  20. Find total number of pixels:
+     *
+     *  [TOTAL PIXELS] = [TOTAL ACTIVE PIXELS] + [H BLANK (PIXELS)]
+     */
+
+    total_pixels = total_active_pixels + h_blank;
+    
+    print_value(20, "[TOTAL PIXELS]", total_pixels);
+    
+
+    /*  21. Find pixel clock frequency:
+     *
+     *  [PIXEL FREQ] = [TOTAL PIXELS] / [H PERIOD]
+     */
+    
+    pixel_freq = total_pixels / h_period;
+    
+    print_value(21, "[PIXEL FREQ]", pixel_freq);
+    
+
+    /*  22. Find horizontal frequency:
+     *
+     *  [H FREQ] = 1000 / [H PERIOD]
+     */
+
+    h_freq = 1000.0 / h_period;
+    
+    print_value(22, "[H FREQ]", h_freq);
+    
+
+
+    /* Stage 1 computations are now complete; I should really pass
+       the results to another function and do the Stage 2
+       computations, but I only need a few more values so I'll just
+       append the computations here for now */
+
+    
+
+    /*  17. Find the number of pixels in the horizontal sync period:
+     *
+     *  [H SYNC (PIXELS)] =(ROUND(([H SYNC%] / 100 * [TOTAL PIXELS] /
+     *                             [CELL GRAN RND]),0))*[CELL GRAN RND]
+     */
+
+    h_sync = rint(H_SYNC_PERCENT/100.0 * total_pixels / CELL_GRAN) * CELL_GRAN;
+
+    print_value(17, "[H SYNC (PIXELS)]", h_sync);
+    
+
+    /*  18. Find the number of pixels in the horizontal front porch period:
+     *
+     *  [H FRONT PORCH (PIXELS)] = ([H BLANK (PIXELS)]/2)-[H SYNC (PIXELS)]
+     */
+
+    h_front_porch = (h_blank / 2.0) - h_sync;
+
+    print_value(18, "[H FRONT PORCH (PIXELS)]", h_front_porch);
+    
+    
+    /*  36. Find the number of lines in the odd front porch period:
+     *
+     *  [V ODD FRONT PORCH(LINES)]=([MIN PORCH RND]+[INTERLACE])
+     */
+    
+    v_odd_front_porch_lines = MIN_PORCH + interlace;
+    
+    print_value(36, "[V ODD FRONT PORCH(LINES)]", v_odd_front_porch_lines);
+    
+
+    /* finally, pack the results in the mode struct */
+    
+    m->hr  = (int) (h_pixels_rnd);
+    m->hss = (int) (h_pixels_rnd + h_front_porch);
+    m->hse = (int) (h_pixels_rnd + h_front_porch + h_sync);
+    m->hfl = (int) (total_pixels);
+
+    m->vr  = (int) (v_lines_rnd);
+    m->vss = (int) (v_lines_rnd + v_odd_front_porch_lines);
+    m->vse = (int) (int) (v_lines_rnd + v_odd_front_porch_lines + V_SYNC_RQD);
+    m->vfl = (int) (total_v_lines);
+
+    m->pclk   = pixel_freq;
+    m->h_freq = h_freq;
+    m->v_freq = freq;
+
+    return m;
+    
+}
+
+
+
+
+/*
+ * parse_command_line() - parse the command line and return an
+ * alloced structure containing the results.  On error print usage
+ * and return NULL.
+ */ 
+
+options *parse_command_line (int argc, char *argv[])
+{
+    int n;
+
+    options *o = (options *) calloc (1, sizeof (options));
+
+    if (argc < 4) goto bad_option;
+
+    o->x = atoi (argv[1]);
+    o->y = atoi (argv[2]);
+    o->v_freq = atof (argv[3]);
+
+    /* XXX should check for errors in the above */
+    
+    n = 4;
+
+    while (n < argc) {
+        if ((strcmp (argv[n], "-v") == 0) ||
+            (strcmp (argv[n], "--verbose") == 0)) {
+            global_verbose = 1;
+        } else if ((strcmp (argv[n], "-f") == 0) ||
+                   (strcmp (argv[n], "--fbmode") == 0)) {
+            o->fbmode = 1;
+        } else if ((strcmp (argv[n], "-x") == 0) ||
+		   (strcmp (argv[n], "--xorgmode") == 0) ||
+                   (strcmp (argv[n], "--xf86mode") == 0)) {
+            o->xorgmode = 1;
+        } else {
+            goto bad_option;
+        }
+        
+        n++;
+    }
+
+    /* if neither xorgmode nor fbmode were requested, default to
+       xorgmode */
+
+    if (!o->fbmode && !o->xorgmode) o->xorgmode = 1;
+    
+    return o;
+    
+ bad_option:
+
+    fprintf (stderr, "\n");
+    fprintf (stderr, "usage: %s x y refresh [-v|--verbose] "
+             "[-f|--fbmode] [-x|--xorgmode]\n", argv[0]);
+
+    fprintf (stderr, "\n");
+    
+    fprintf (stderr, "            x : the desired horizontal "
+             "resolution (required)\n");
+    fprintf (stderr, "            y : the desired vertical "
+             "resolution (required)\n");
+    fprintf (stderr, "      refresh : the desired refresh "
+             "rate (required)\n");
+    fprintf (stderr, " -v|--verbose : enable verbose printouts "
+             "(traces each step of the computation)\n");
+    fprintf (stderr, "  -f|--fbmode : output an fbset(8)-style mode "
+             "description\n");
+    fprintf (stderr, " -x|--xorgmode : output an "__XSERVERNAME__"-style mode "
+             "description (this is the default\n"
+             "                if no mode description is requested)\n");
+    
+    fprintf (stderr, "\n");
+    
+    free (o);
+    return NULL;
+
+}
+
+
+
+int main (int argc, char *argv[])
+{
+    mode *m;
+    options *o;
+
+    o = parse_command_line (argc, argv);
+    if (!o) exit (1);
+    
+    m = vert_refresh (o->x, o->y, o->v_freq, 0, 0);
+    if (!m) exit (1);
+
+    if (o->xorgmode)
+        print_xf86_mode(m);
+    
+    if (o->fbmode)
+        print_fb_mode(m);
+    
+    return 0;
+    
+}