repos/svgalib-1
1
Fork 0
Code Issues Pull requests Projects Releases 1 Packages Wiki Activity Actions

Initial. Don't... just don't ask.

Browse source
This commit is contained in:
Ryan McGrath 2011-02-24 00:22:00 -08:00
commit 00bae13bba
586 changed files with 129057 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

152
utils/gtf/gtf.h Normal file
View file

@ -0,0 +1,152 @@
/****************************************************************************
*
* VESA Generalized Timing Formula (GTF)
* Version 1.0
*
* ========================================================================
*
* 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: Header file for generating GTF compatible timings given a
* set of input requirements. Translated from the original GTF
* 1.14 spreadsheet definition.
*
*
****************************************************************************/
#ifndef __GTF_H
#define __GTF_H
#ifndef __SCITECH_H
#include "scitech.h"
#endif
/*---------------------- Macros and type definitions ----------------------*/
/* Define the structures for holding the horizontal and vertical
* CRTC parameters for a mode.
*
* Note: The sync timings are defined in both VGA compatible timings
* (sync start and sync end positions) and also in GTF compatible
* modes with the front porch, sync width and back porch defined.
*/
typedef struct {
int hTotal; /* Horizontal total */
int hDisp; /* Horizontal displayed */
int hSyncStart; /* Horizontal sync start */
int hSyncEnd; /* Horizontal sync end */
int hFrontPorch; /* Horizontal front porch */
int hSyncWidth; /* Horizontal sync width */
int hBackPorch; /* Horizontal back porch */
} GTF_hCRTC;
typedef struct {
int vTotal; /* Vertical total */
int vDisp; /* Vertical displayed */
int vSyncStart; /* Vertical sync start */
int vSyncEnd; /* Vertical sync end */
int vFrontPorch; /* Vertical front porch */
int vSyncWidth; /* Vertical sync width */
int vBackPorch; /* Vertical back porch */
} GTF_vCRTC;
/* Define the main structure for holding generated GTF timings */
typedef struct {
GTF_hCRTC h; /* Horizontal CRTC paremeters */
GTF_vCRTC v; /* Vertical CRTC parameters */
char hSyncPol; /* Horizontal sync polarity */
char vSyncPol; /* Vertical sync polarity */
char interlace; /* 'I' for Interlace, 'N' for Non */
double vFreq; /* Vertical frequency (Hz) */
double hFreq; /* Horizontal frequency (KHz) */
double dotClock; /* Pixel clock (Mhz) */
} GTF_timings;
/* Define the structure for holding standard GTF formula constants */
typedef struct {
double margin; /* Margin size as percentage of display */
double cellGran; /* Character cell granularity */
double minPorch; /* Minimum front porch in lines/chars */
double vSyncRqd; /* Width of V sync in lines */
double hSync; /* Width of H sync as percent of total */
double minVSyncBP; /* Minimum vertical sync + back porch (us) */
double m; /* Blanking formula gradient */
double c; /* Blanking formula offset */
double k; /* Blanking formula scaling factor */
double j; /* Blanking formula scaling factor weight */
} GTF_constants;
#define GTF_lockVF 1 /* Lock to vertical frequency */
#define GTF_lockHF 2 /* Lock to horizontal frequency */
#define GTF_lockPF 3 /* Lock to pixel clock frequency */
/*-------------------------- Function Prototypes --------------------------*/
#ifdef __cplusplus
extern "C" { /* Use "C" linkage when in C++ mode */
#endif
/* Generate a set of timings for a mode from the GTF formulas. This will
* allow you to generate a set of timings by specifying the type as:
*
* 1. Vertical frequency
* 2. Horizontal frequency
* 3. Pixel clock
*
* Generally if you want to find the timings for a specific vertical
* frequency, you may want to generate a first set of timings given the
* desired vertical frequency, which will give you a specific horizontal
* frequency and dot clock. You can then adjust the dot clock to a value
* that is known to be available on the underlying hardware, and then
* regenerate the timings for that particular dot clock to determine what
* the exact final timings will be.
*
* Alternatively if you only have a fixed set of dot clocks available such
* as on older controllers, you can simply run through the set of available
* dot clocks, and generate a complete set of all available timings that
* can be generated with the set of available dot clocks (and filter out
* unuseable values say < 60Hz and > 120Hz).
*/
void GTF_calcTimings(double hPixels,double vLines,double freq,int type,
ibool wantMargins,ibool wantInterlace,GTF_timings *timings);
/* Functions to read and write the current set of GTF formula constants.
* These constants should be left in the default state that is defined
* by the current version of the GTF specification. However newer DDC
* monitos that support the GTF specification may be able to pass back a
* table of GTF constants to fine tune the GTF timings for their particular
* requirements.
*/
void GTF_getConstants(GTF_constants *constants);
void GTF_setConstants(GTF_constants *constants);
#ifdef __cplusplus
} /* End of "C" linkage for C++ */
#endif
#endif /* __GTF_H */