mirror of
https://github.com/alfishe/amiga-bootcamp.git
synced 2026-06-13 00:26:28 +00:00
91 lines
3 KiB
Markdown
91 lines
3 KiB
Markdown
|
[← Home](../README.md) · [Graphics](README.md)
|
||
|
|
|
||
|
|
# GfxBase — Graphics Library Global State
|
||
|
|
|
||
|
|
## Overview
|
||
|
|
|
||
|
|
`graphics.library` manages all display output, drawing primitives, and custom chip programming. `GfxBase` is the library base containing display state, chip revision info, and the system copper lists.
|
||
|
|
|
||
|
|
---
|
||
|
|
|
||
|
|
## struct GfxBase (Key Fields)
|
||
|
|
|
||
|
|
```c
|
||
|
|
/* graphics/gfxbase.h — NDK39 */
|
||
|
|
struct GfxBase {
|
||
|
|
struct Library LibNode;
|
||
|
|
struct View *ActiView; /* currently active View */
|
||
|
|
struct copinit *copinit; /* system copper list init */
|
||
|
|
LONG *cia; /* CIA base (deprecated) */
|
||
|
|
LONG *blitter; /* blitter base (deprecated) */
|
||
|
|
UWORD *LOFlist; /* long-frame copper list pointer */
|
||
|
|
UWORD *SHFlist; /* short-frame copper list (interlace) */
|
||
|
|
struct bltnode *blthd; /* blitter queue head */
|
||
|
|
struct bltnode *blttl; /* blitter queue tail */
|
||
|
|
struct bltnode *bsblthd;
|
||
|
|
struct bltnode *bsblttl;
|
||
|
|
struct Interrupt vbsrv; /* vertical blank server list */
|
||
|
|
struct Interrupt timsrv;
|
||
|
|
struct Interrupt bltsrv;
|
||
|
|
struct List TextFonts; /* system font list */
|
||
|
|
struct TextFont *DefaultFont; /* default system font */
|
||
|
|
UWORD Modes; /* current display mode bits */
|
||
|
|
BYTE VBlankFrequency; /* 50 (PAL) or 60 (NTSC) */
|
||
|
|
BYTE DisplayFlags; /* PAL/NTSC/GENLOCK flags */
|
||
|
|
UWORD NormalDisplayColumns;
|
||
|
|
UWORD NormalDisplayRows;
|
||
|
|
UWORD MaxDisplayColumn;
|
||
|
|
UWORD MaxDisplayRow;
|
||
|
|
UWORD ChipRevBits0; /* chip revision flags */
|
||
|
|
/* ... many more fields ... */
|
||
|
|
struct MonitorSpec *monitor_id;
|
||
|
|
struct List MonitorList;
|
||
|
|
struct List ModesList; /* display mode database */
|
||
|
|
UBYTE MemType; /* memory type flags */
|
||
|
|
/* OS 3.x additions */
|
||
|
|
APTR ChunkyToPlanarPtr; /* c2p conversion routine */
|
||
|
|
};
|
||
|
|
```
|
||
|
|
|
||
|
|
---
|
||
|
|
|
||
|
|
## Chip Revision Detection
|
||
|
|
|
||
|
|
```c
|
||
|
|
/* graphics/gfxbase.h */
|
||
|
|
#define GFXB_BIG_BLITS 0 /* big blitter (ECS Agnus) */
|
||
|
|
#define GFXB_HR_AGNUS 0 /* same — hi-res Agnus */
|
||
|
|
#define GFXB_HR_DENISE 1 /* ECS Denise (SuperHires, scan-doubling) */
|
||
|
|
#define GFXB_AA_ALICE 2 /* AGA Alice (A1200/A4000) */
|
||
|
|
#define GFXB_AA_LISA 3 /* AGA Lisa */
|
||
|
|
#define GFXB_AA_MLISA 4 /* AGA Lisa (modified) */
|
||
|
|
|
||
|
|
#define GFXF_BIG_BLITS (1<<0)
|
||
|
|
#define GFXF_HR_AGNUS (1<<0)
|
||
|
|
#define GFXF_HR_DENISE (1<<1)
|
||
|
|
#define GFXF_AA_ALICE (1<<2)
|
||
|
|
#define GFXF_AA_LISA (1<<3)
|
||
|
|
#define GFXF_AA_MLISA (1<<4)
|
||
|
|
|
||
|
|
/* Check for AGA: */
|
||
|
|
if (GfxBase->ChipRevBits0 & GFXF_AA_ALICE) {
|
||
|
|
/* AGA chipset — 8-bit planar, 256 colours in indexed mode */
|
||
|
|
}
|
||
|
|
```
|
||
|
|
|
||
|
|
---
|
||
|
|
|
||
|
|
## PAL vs NTSC
|
||
|
|
|
||
|
|
```c
|
||
|
|
if (GfxBase->VBlankFrequency == 50) /* PAL: 50Hz, 625 lines */
|
||
|
|
if (GfxBase->VBlankFrequency == 60) /* NTSC: 60Hz, 525 lines */
|
||
|
|
```
|
||
|
|
|
||
|
|
---
|
||
|
|
|
||
|
|
## References
|
||
|
|
|
||
|
|
- NDK39: `graphics/gfxbase.h`
|
||
|
|
- ADCD 2.1: graphics.library autodocs
|