summaryrefslogtreecommitdiff
path: root/board/MAI/bios_emulator/scitech/src/common/gtfcalc.c
diff options
context:
space:
mode:
Diffstat (limited to 'board/MAI/bios_emulator/scitech/src/common/gtfcalc.c')
-rw-r--r--board/MAI/bios_emulator/scitech/src/common/gtfcalc.c436
1 files changed, 436 insertions, 0 deletions
diff --git a/board/MAI/bios_emulator/scitech/src/common/gtfcalc.c b/board/MAI/bios_emulator/scitech/src/common/gtfcalc.c
new file mode 100644
index 000000000..5a03ac588
--- /dev/null
+++ b/board/MAI/bios_emulator/scitech/src/common/gtfcalc.c
@@ -0,0 +1,436 @@
+/****************************************************************************
+*
+* VESA Generalized Timing Formula (GTF)
+* Version 1.1
+*
+* ========================================================================
+*
+* The contents of this file are subject to the SciTech MGL Public
+* License Version 1.0 (the "License"); you may not use this file
+* except in compliance with the License. You may obtain a copy of
+* the License at http://www.scitechsoft.com/mgl-license.txt
+*
+* Software distributed under the License is distributed on an
+* "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
+* implied. See the License for the specific language governing
+* rights and limitations under the License.
+*
+* The Original Code is Copyright (C) 1991-1998 SciTech Software, Inc.
+*
+* The Initial Developer of the Original Code is SciTech Software, Inc.
+* All Rights Reserved.
+*
+* ========================================================================
+*
+* Developed by: SciTech Software, Inc.
+*
+* Language: ANSI C
+* Environment: Any.
+*
+* Description: C module for generating GTF compatible timings given a set
+* of input requirements. Translated from the original GTF
+* 1.14 spreadsheet definition.
+*
+* Compile with #define TESTING to build a command line test
+* program.
+*
+* NOTE: The code in here has been written for clarity and
+* to follow the original GTF spec as closely as
+* possible.
+*
+****************************************************************************/
+
+#include "gtf.h"
+#ifndef __WIN32_VXD__
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#include <math.h>
+#endif
+
+/*------------------------- Global Variables ------------------------------*/
+
+static GTF_constants GC = {
+ 1.8, /* Margin size as percentage of display */
+ 8, /* Character cell granularity */
+ 1, /* Minimum front porch in lines/chars */
+ 3, /* Width of V sync in lines */
+ 8, /* Width of H sync as percent of total */
+ 550, /* Minimum vertical sync + back porch (us) */
+ 600, /* Blanking formula gradient */
+ 40, /* Blanking formula offset */
+ 128, /* Blanking formula scaling factor */
+ 20, /* Blanking formula scaling factor weight */
+ };
+
+/*-------------------------- Implementation -------------------------------*/
+
+#ifdef __WIN32_VXD__
+/* These functions are not supported in a VxD, so we stub them out so this
+ * module will at least compile. Calling the functions in here will do
+ * something wierd!
+ */
+double sqrt(double x)
+{ return x; }
+
+double floor(double x)
+{ return x; }
+
+double pow(double x,double y)
+{ return x*y; }
+#endif
+
+static double round(double v)
+{
+ return floor(v + 0.5);
+}
+
+static void GetInternalConstants(GTF_constants *c)
+/****************************************************************************
+*
+* Function: GetInternalConstants
+* Parameters: c - Place to store the internal constants
+*
+* Description: Calculates the rounded, internal set of GTF constants.
+* These constants are different to the real GTF constants
+* that can be set up for the monitor. The calculations to
+* get these real constants are defined in the 'Work Area'
+* after the constants are defined in the Excel spreadsheet.
+*
+****************************************************************************/
+{
+ c->margin = GC.margin;
+ c->cellGran = round(GC.cellGran);
+ c->minPorch = round(GC.minPorch);
+ c->vSyncRqd = round(GC.vSyncRqd);
+ c->hSync = GC.hSync;
+ c->minVSyncBP = GC.minVSyncBP;
+ if (GC.k == 0)
+ c->k = 0.001;
+ else
+ c->k = GC.k;
+ c->m = (c->k / 256) * GC.m;
+ c->c = (GC.c - GC.j) * (c->k / 256) + GC.j;
+ c->j = GC.j;
+}
+
+void GTF_calcTimings(double hPixels,double vLines,double freq,
+ int type,ibool wantMargins,ibool wantInterlace,GTF_timings *t)
+/****************************************************************************
+*
+* Function: GTF_calcTimings
+* Parameters: hPixels - X resolution
+* vLines - Y resolution
+* freq - Frequency (Hz, KHz or MHz depending on type)
+* type - 1 - vertical, 2 - horizontal, 3 - dot clock
+* margins - True if margins should be generated
+* interlace - True if interlaced timings to be generated
+* t - Place to store the resulting timings
+*
+* Description: Calculates a set of GTF timing parameters given a specified
+* resolution and vertical frequency. The horizontal frequency
+* and dot clock will be automatically generated by this
+* routines.
+*
+* For interlaced modes the CRTC parameters are calculated for
+* a single field, so will be half what would be used in
+* a non-interlaced mode.
+*
+****************************************************************************/
+{
+ double interlace,vFieldRate,hPeriod;
+ double topMarginLines,botMarginLines;
+ double leftMarginPixels,rightMarginPixels;
+ double hPeriodEst,vSyncBP,vBackPorch;
+ double vTotalLines,vFieldRateEst;
+ double hTotalPixels,hTotalActivePixels,hBlankPixels;
+ double idealDutyCycle,hSyncWidth,hSyncBP,hBackPorch;
+ double idealHPeriod;
+ double vFreq,hFreq,dotClock;
+ GTF_constants c;
+
+ /* Get rounded GTF constants used for internal calculations */
+ GetInternalConstants(&c);
+
+ /* Move input parameters into appropriate variables */
+ vFreq = hFreq = dotClock = freq;
+
+ /* Round pixels to character cell granularity */
+ hPixels = round(hPixels / c.cellGran) * c.cellGran;
+
+ /* For interlaced mode halve the vertical parameters, and double
+ * the required field refresh rate.
+ */
+ vFieldRate = vFreq;
+ interlace = 0;
+ if (wantInterlace)
+ dotClock *= 2;
+
+ /* Determine the lines for margins */
+ if (wantMargins) {
+ topMarginLines = round(c.margin / 100 * vLines);
+ botMarginLines = round(c.margin / 100 * vLines);
+ }
+ else {
+ topMarginLines = 0;
+ botMarginLines = 0;
+ }
+
+ if (type != GTF_lockPF) {
+ if (type == GTF_lockVF) {
+ /* Estimate the horizontal period */
+ hPeriodEst = ((1/vFieldRate) - (c.minVSyncBP/1000000)) /
+ (vLines + (2*topMarginLines) + c.minPorch + interlace) * 1000000;
+
+ /* Find the number of lines in vSync + back porch */
+ vSyncBP = round(c.minVSyncBP / hPeriodEst);
+ }
+ else if (type == GTF_lockHF) {
+ /* Find the number of lines in vSync + back porch */
+ vSyncBP = round((c.minVSyncBP * hFreq) / 1000);
+ }
+
+ /* Find the number of lines in the V back porch alone */
+ vBackPorch = vSyncBP - c.vSyncRqd;
+
+ /* Find the total number of lines in the vertical period */
+ vTotalLines = vLines + topMarginLines + botMarginLines + vSyncBP
+ + interlace + c.minPorch;
+
+ if (type == GTF_lockVF) {
+ /* Estimate the vertical frequency */
+ vFieldRateEst = 1000000 / (hPeriodEst * vTotalLines);
+
+ /* Find the actual horizontal period */
+ hPeriod = (hPeriodEst * vFieldRateEst) / vFieldRate;
+
+ /* Find the actual vertical field frequency */
+ vFieldRate = 1000000 / (hPeriod * vTotalLines);
+ }
+ else if (type == GTF_lockHF) {
+ /* Find the actual vertical field frequency */
+ vFieldRate = (hFreq / vTotalLines) * 1000;
+ }
+ }
+
+ /* Find the number of pixels in the left and right margins */
+ if (wantMargins) {
+ leftMarginPixels = round(hPixels * c.margin) / (100 * c.cellGran);
+ rightMarginPixels = round(hPixels * c.margin) / (100 * c.cellGran);
+ }
+ else {
+ leftMarginPixels = 0;
+ rightMarginPixels = 0;
+ }
+
+ /* Find the total number of active pixels in image + margins */
+ hTotalActivePixels = hPixels + leftMarginPixels + rightMarginPixels;
+
+ if (type == GTF_lockVF) {
+ /* Find the ideal blanking duty cycle */
+ idealDutyCycle = c.c - ((c.m * hPeriod) / 1000);
+ }
+ else if (type == GTF_lockHF) {
+ /* Find the ideal blanking duty cycle */
+ idealDutyCycle = c.c - (c.m / hFreq);
+ }
+ else if (type == GTF_lockPF) {
+ /* Find ideal horizontal period from blanking duty cycle formula */
+ idealHPeriod = (((c.c - 100) + (sqrt((pow(100-c.c,2)) +
+ (0.4 * c.m * (hTotalActivePixels + rightMarginPixels +
+ leftMarginPixels) / dotClock)))) / (2 * c.m)) * 1000;
+
+ /* Find the ideal blanking duty cycle */
+ idealDutyCycle = c.c - ((c.m * idealHPeriod) / 1000);
+ }
+
+ /* Find the number of pixels in blanking time */
+ hBlankPixels = round((hTotalActivePixels * idealDutyCycle) /
+ ((100 - idealDutyCycle) * c.cellGran)) * c.cellGran;
+
+ /* Find the total number of pixels */
+ hTotalPixels = hTotalActivePixels + hBlankPixels;
+
+ /* Find the horizontal back porch */
+ hBackPorch = round((hBlankPixels / 2) / c.cellGran) * c.cellGran;
+
+ /* Find the horizontal sync width */
+ hSyncWidth = round(((c.hSync/100) * hTotalPixels) / c.cellGran) * c.cellGran;
+
+ /* Find the horizontal sync + back porch */
+ hSyncBP = hBackPorch + hSyncWidth;
+
+ if (type == GTF_lockPF) {
+ /* Find the horizontal frequency */
+ hFreq = (dotClock / hTotalPixels) * 1000;
+
+ /* Find the number of lines in vSync + back porch */
+ vSyncBP = round((c.minVSyncBP * hFreq) / 1000);
+
+ /* Find the number of lines in the V back porch alone */
+ vBackPorch = vSyncBP - c.vSyncRqd;
+
+ /* Find the total number of lines in the vertical period */
+ vTotalLines = vLines + topMarginLines + botMarginLines + vSyncBP
+ + interlace + c.minPorch;
+
+ /* Find the actual vertical field frequency */
+ vFieldRate = (hFreq / vTotalLines) * 1000;
+ }
+ else {
+ if (type == GTF_lockVF) {
+ /* Find the horizontal frequency */
+ hFreq = 1000 / hPeriod;
+ }
+ else if (type == GTF_lockHF) {
+ /* Find the horizontal frequency */
+ hPeriod = 1000 / hFreq;
+ }
+
+ /* Find the pixel clock frequency */
+ dotClock = hTotalPixels / hPeriod;
+ }
+
+ /* Return the computed frequencies */
+ t->vFreq = vFieldRate;
+ t->hFreq = hFreq;
+ t->dotClock = dotClock;
+
+ /* Determine the vertical timing parameters */
+ t->h.hTotal = (int)hTotalPixels;
+ t->h.hDisp = (int)hTotalActivePixels;
+ t->h.hSyncStart = t->h.hTotal - (int)hSyncBP;
+ t->h.hSyncEnd = t->h.hTotal - (int)hBackPorch;
+ t->h.hFrontPorch = t->h.hSyncStart - t->h.hDisp;
+ t->h.hSyncWidth = (int)hSyncWidth;
+ t->h.hBackPorch = (int)hBackPorch;
+
+ /* Determine the vertical timing parameters */
+ t->v.vTotal = (int)vTotalLines;
+ t->v.vDisp = (int)vLines;
+ t->v.vSyncStart = t->v.vTotal - (int)vSyncBP;
+ t->v.vSyncEnd = t->v.vTotal - (int)vBackPorch;
+ t->v.vFrontPorch = t->v.vSyncStart - t->v.vDisp;
+ t->v.vSyncWidth = (int)c.vSyncRqd;
+ t->v.vBackPorch = (int)vBackPorch;
+ if (wantInterlace) {
+ /* Halve the timings for interlaced modes */
+ t->v.vTotal /= 2;
+ t->v.vDisp /= 2;
+ t->v.vSyncStart /= 2;
+ t->v.vSyncEnd /= 2;
+ t->v.vFrontPorch /= 2;
+ t->v.vSyncWidth /= 2;
+ t->v.vBackPorch /= 2;
+ t->dotClock /= 2;
+ }
+
+ /* Mark as GTF timing using the sync polarities */
+ t->interlace = (wantInterlace) ? 'I' : 'N';
+ t->hSyncPol = '-';
+ t->vSyncPol = '+';
+}
+
+void GTF_getConstants(GTF_constants *constants)
+{ *constants = GC; }
+
+void GTF_setConstants(GTF_constants *constants)
+{ GC = *constants; }
+
+#ifdef TESTING_GTF
+
+void main(int argc,char *argv[])
+{
+ FILE *f;
+ double xPixels,yPixels,freq;
+ ibool interlace;
+ GTF_timings t;
+
+ if (argc != 5 && argc != 6) {
+ printf("Usage: GTFCALC <xPixels> <yPixels> <freq> [[Hz] [KHz] [MHz]] [I]\n");
+ printf("\n");
+ printf("where <xPixels> is the horizontal resolution of the mode, <yPixels> is the\n");
+ printf("vertical resolution of the mode. The <freq> value will be the frequency to\n");
+ printf("drive the calculations, and will be either the vertical frequency (in Hz)\n");
+ printf("the horizontal frequency (in KHz) or the dot clock (in MHz). To generate\n");
+ printf("timings for an interlaced mode, add 'I' to the end of the command line.\n");
+ printf("\n");
+ printf("For example to generate timings for 640x480 at 60Hz vertical:\n");
+ printf("\n");
+ printf(" GTFCALC 640 480 60 Hz\n");
+ printf("\n");
+ printf("For example to generate timings for 640x480 at 31.5KHz horizontal:\n");
+ printf("\n");
+ printf(" GTFCALC 640 480 31.5 KHz\n");
+ printf("\n");
+ printf("For example to generate timings for 640x480 with a 25.175Mhz dot clock:\n");
+ printf("\n");
+ printf(" GTFCALC 640 480 25.175 MHz\n");
+ printf("\n");
+ printf("GTFCALC will print a summary of the results found, and dump the CRTC\n");
+ printf("values to the UVCONFIG.CRT file in the format used by SciTech Display Doctor.\n");
+ exit(1);
+ }
+
+ /* Get values from command line */
+ xPixels = atof(argv[1]);
+ yPixels = atof(argv[2]);
+ freq = atof(argv[3]);
+ interlace = ((argc == 6) && (argv[5][0] == 'I'));
+
+ /* Compute the CRTC timings */
+ if (toupper(argv[4][0]) == 'H')
+ GTF_calcTimings(xPixels,yPixels,freq,GTF_lockVF,false,interlace,&t);
+ else if (toupper(argv[4][0]) == 'K')
+ GTF_calcTimings(xPixels,yPixels,freq,GTF_lockHF,false,interlace,&t);
+ else if (toupper(argv[4][0]) == 'M')
+ GTF_calcTimings(xPixels,yPixels,freq,GTF_lockPF,false,interlace,&t);
+ else {
+ printf("Unknown command line!\n");
+ exit(1);
+ }
+
+ /* Dump summary info to standard output */
+ printf("CRTC values for %.0fx%.0f @ %.2f %s\n", xPixels, yPixels, freq, argv[4]);
+ printf("\n");
+ printf(" hTotal = %-4d vTotal = %-4d\n",
+ t.h.hTotal, t.v.vTotal);
+ printf(" hDisp = %-4d vDisp = %-4d\n",
+ t.h.hDisp, t.v.vDisp);
+ printf(" hSyncStart = %-4d vSyncStart = %-4d\n",
+ t.h.hSyncStart, t.v.vSyncStart);
+ printf(" hSyncEnd = %-4d vSyncEnd = %-4d\n",
+ t.h.hSyncEnd, t.v.vSyncEnd);
+ printf(" hFrontPorch = %-4d vFrontPorch = %-4d\n",
+ t.h.hFrontPorch, t.v.vFrontPorch);
+ printf(" hSyncWidth = %-4d vSyncWidth = %-4d\n",
+ t.h.hSyncWidth, t.v.vSyncWidth);
+ printf(" hBackPorch = %-4d vBackPorch = %-4d\n",
+ t.h.hBackPorch, t.v.vBackPorch);
+ printf("\n");
+ printf(" Interlaced = %s\n", (t.interlace == 'I') ? "Yes" : "No");
+ printf(" H sync pol = %c\n", t.hSyncPol);
+ printf(" V sync pol = %c\n", t.vSyncPol);
+ printf("\n");
+ printf(" Vert freq = %.2f Hz\n", t.vFreq);
+ printf(" Horiz freq = %.2f KHz\n", t.hFreq);
+ printf(" Dot Clock = %.2f Mhz\n", t.dotClock);
+
+ /* Dump to file in format used by SciTech Display Doctor */
+ if ((f = fopen("UVCONFIG.CRT","w")) != NULL) {
+ fprintf(f, "[%.0f %.0f]\n", xPixels, yPixels);
+ fprintf(f, "%d %d %d %d '%c' %s\n",
+ t.h.hTotal, t.h.hDisp,
+ t.h.hSyncStart, t.h.hSyncEnd,
+ t.hSyncPol, (t.interlace == 'I') ? "I" : "NI");
+ fprintf(f, "%d %d %d %d '%c'\n",
+ t.v.vTotal, t.v.vDisp,
+ t.v.vSyncStart, t.v.vSyncEnd,
+ t.vSyncPol);
+ fprintf(f, "%.2f\n", t.dotClock);
+ fclose(f);
+ }
+}
+
+#endif /* TESTING */
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-10-31 18:07:48 +0000