--- /dev/null
+Graphics is still a prototype.
+
+The proposed method of operation is as follows
+
+Issue ioctl(ttyfd, GFXIOC_GETINFO , &display)
+
+An error means no graphics support, otherwise you get the display data for
+the default mode.
+
+If it reports GFX_PALETTE then you can get the palette entries and try
+and set them.
+
+If it reports GFX_MULTIMODE then you can call GFXIOC_GETMODE with a uint8_t
+set and get back a full buffer of the display for that mode.
+
+The formats defined so far are
+
+FMT_MONO_BW Black with white monochrome bitmap. The data
+ is on lines stride pixels wide, bit 7 is left
+FMT_MONO_WB Ditto but white with black
+
+These are the most common small device modes and are defined this way to
+avoid needing palette support on the tiniest devices.
+
+FMT_COLOUR4 2bit packed pixel
+FMT_COLOUR16 4bit packed pixel
+FMT_SPECTRUM ZX Spectrum
+FMT_VDP VDP display (which is mostly plain weird)
+
+Hardware types are defined for
+
+HW_UNACCEL Just a framebuffer of some kind
+HW_VDP_9918 MSX1, MTX and similar
+HW_VDP_9938 MSX2
+
+It's assumed that for some stuff certain apps will want to go direct to GPU
+hence this information.
+
+The properties are
+
+GFX_MAPPABLE Can be accessed if mapped as part of process memory
+ (Mostly for 16/32bit platforms)
+GFX_PALETTE Has a colour palette palette ioctls
+GFX_OFFSCREEN It is meaningful to write or read memory in the full
+ physical range not just the displayed window
+GFX_VBLANK Supports wait for vblank
+GFX_ENABLE Graphics mode must be enabled/disabled (ie its not
+ just the text mode too)
+GFX_MULTIMODE There are multiple display modes possible
+GFX_PALETTE_SET The colour table is settable
+
+Memory holds the amount of RAM for hardware where this also matters (VDP
+primarily ?, otherwise 0)
+
+Commands are again organised to try and minimise size for small devices
+
+GFX_BLTAL_CG Rectangular blit or byte aligned blocks from CPU to
+ the screen
+GFX_BLTAL_GC The reverse
+GFX_SETPIXEL Plot a list of pixels
+GFX_HLINE Horizontal line (on many devices even for software
+ this can be done with optimised methods)
+GFX_VLINE Similar for verticals
+GFX_LINE Arbitrary line from A to B, for accelerator hardware
+GFX_BLT_GG Arbitrary screen to screen memory copy. Mainly for
+ things like VDP2
+GFX_BLT_CG As the aligned blit but any alignment
+GFX_BLT_GC Ditto in reverse
+GFX_RECT Solid rectangle (or patterned if supported)
+GFX_RAW Direct command streams (eg VDP). Device specific
+GFX_RAWCOPY For non mapped non accelerated screens, each command
+ describes a block copy
+
+MODE_XOR XOR drawing mode is supported
+MODE_PATTERN 8x8 Pattern fill is allowed
+
+There are things that need covering if they make sense
+- Sprite discovery, description, setup and movement
+- Blit with stencil
+
+The attributes describe colours and drawing modes.
+
+The basic idea is that a typical 8bit unaccelerated device need only support
+a few minimal operations and most ioctls can be completely ignored but we
+still can support smarter devices while having a direct route for accelerators
+for those cases they are needed (eg games)
+
+HLINE is worth having because in most cases that is faster if done by
+masking the ends and just setting/clearing/cpl the midstream bytes
+
+VLINE is a repeated operation while adding scanline of bytes
+
+RECT covers both and also the useful to optimise case of narrow rectangles
+where its a 1 or 2 byte wide drawing done akin to vline optimisations
+
+The BLTAL blit operations try and keep the logic simple and the code fast
+for the faster paths. It's sufficient for a lot of stuff including 8 pixel
+aligned font work, bitmaps, and double buffering work.
+
+
+Need to decide on the best approach for text and fonts
+
+Some hand optimised standard asm implementations of the rect/vline/hline and
+blits would also be worth having.
+
+
--- /dev/null
+#ifndef _GRAPHICS_H
+#define _GRAPHICS_H
+
+/* We use the same structure for modes */
+struct display {
+ uint16_t width, height; /* Logical display size */
+ uint16_t stride, lines; /* Physical layout */
+ uint8_t vstep, hstep; /* Scrolling step if supported or 0xFF */
+ uint8_t format;
+#define FMT_MONO_BW 0
+#define FMT_MONO_WB 1
+#define FMT_COLOUR4 2
+#define FMT_COLOUR16 3
+/* Those sufficiently funky */
+#define FMT_SPECTRUM 128
+#define FMT_VDP 129 /* VDP graphics engines */
+ uint8_t hardware;
+#define HW_UNACCEL 1 /* Simple display */
+#define HW_VDP_9918 128 /* Not neccessarily MSX... */
+#define HW_VDP_9938 129
+ uint16_t features;
+#define GFX_MAPPABLE 1 /* Can map into process memory */
+#define GFX_PALETTE 2 /* Has colour palette */
+#define GFX_OFFSCREEN 4 /* Offscreen memory */
+#define GFX_VBLANK 8
+#define GFX_ENABLE 16 /* Separate mode we enable/disable */
+#define GFX_MULTIMODE 32 /* Has multiple modes */
+#define GFX_PALETTE_SET 64 /* Has settable colour palette */
+ uint16_t memory; /* Memory size in KB (may be 0 if not relevant) */
+ uint16_t commands;
+#define GFX_BLTAL_CG 1 /* Aligned blit CPU to graphics */
+#define GFX_BLTAL_GC 2 /* And the reverse */
+#define GFX_SETPIXEL 4 /* Driver supports set/clear pixel */
+#define GFX_HLINE 8 /* Horizontal line */
+#define GFX_VLINE 16 /* Vertical line */
+#define GFX_LINE 32 /* Arbitrary line */
+#define GFX_BLT_GG 64 /* Screen to screen blit */
+#define GFX_BLT_CG 128 /* Unaligned blits */
+#define GFX_BLT_GC 256
+#define GFX_RECT 512 /* Rectangles */
+#define GFX_RAW 1024 /* Raw command streams */
+#define GFX_RAWCOPY 1024 /* Raw command stream is copier format */
+ uint16_t drawmodes;
+#define MODE_XOR 1 /* XOR as well as set/clr */
+#define MODE_PATTERN 2 /* 8x8 pattern */
+};
+
+/* FIXME: need a way to describe/set modes if multiple supported */
+
+struct palette {
+ uint8_t n;
+ uint8_t r,g,b;
+};
+
+/* Do not fiddle with this struct idly - it has asm users */
+struct attribute {
+ uint8_t ink, paper;
+ uint8_t mode;
+#define GFX_OP_COPY 0
+#define GFX_OP_SET 1
+#define GFX_OP_CLEAR 2
+#define GFX_OP_XOR 3
+ uint8_t flags;
+};
+
+#define GFX_BUFLEN 64 /* Default buffer length (128 byte) */
+
+#define GFXIOC_GETINFO 0x0300 /* Query display info for this tty */
+#define GFXIOC_ENABLE 0x0301 /* Enter graphics mode */
+#define GFXIOC_DISABLE 0x0302 /* Exit graphics mode */
+#define GFXIOC_GETPALETTE 0x0303 /* Get a palette entry */
+#define GFXIOC_SETPALETTE 0x0304 /* Set a palette entry */
+#define GFXIOC_MAP 0x0305 /* Map into process if supported */
+#define GFXIOC_UNMAP 0x0306 /* Unmap from process */
+#define GFXIOC_SETATTR 0x0307 /* Set the drawing attributes */
+#define GFXIOC_SETPIXEL 0x0308 /* Set a pixel */
+#define GFXIOC_HLINE 0x0309 /* Horizontal line */
+#define GFXIOC_VLINE 0x030A /* Vertical line */
+#define GFXIOC_RECT 0x030B /* Draw rectangle */
+#define GFXIOC_BLTAL_CG 0x030C /* Blit functions */
+#define GFXIOC_BLTAL_GC 0x030D
+#define GFXIOC_BLTCG 0x030E
+#define GFXIOC_BLTGC 0x030F
+#define GFXIOC_BLTGG 0x0310
+#define GFXIOC_CMD 0x0311 /* Raw command stream for a VDP */
+#define GFXIOC_PAN 0x0312 /* Panning */
+#define GFXIOC_WAITVB 0x0313 /* Wait for vblank */
+#define GFXIOC_GETPIXEL 0x0314 /* Read a pixel */
+#define GFXIOC_GETMODE 0x0315 /* Get info on a mode */
+#define GFXIOC_SETMODE 0x0315 /* Set video mode */
+#endif
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