mirror of
https://github.com/irmen/prog8.git
synced 2024-11-30 08:52:30 +00:00
364 lines
14 KiB
Lua
364 lines
14 KiB
Lua
; Routines to load and save "BMX" files (commander X16 bitmap format) Version 1.
|
|
; Only uncompressed images are supported for now.
|
|
; BMX Specification: https://cx16forum.com/forum/viewtopic.php?t=6945
|
|
|
|
%import diskio
|
|
%option ignore_unused
|
|
|
|
bmx {
|
|
|
|
ubyte[32] header
|
|
str FILEID = petscii:"bmx"
|
|
|
|
ubyte bitsperpixel ; consider using set_bpp() when setting this
|
|
ubyte vera_colordepth ; consider using set_vera_colordepth() when setting this
|
|
uword width
|
|
uword height
|
|
ubyte border
|
|
uword palette_entries ; 1-256
|
|
ubyte palette_start
|
|
ubyte compression
|
|
uword @shared palette_buffer_ptr = 0 ; should you want to load or save the palette into main memory instead of directly into vram
|
|
|
|
uword error_message ; pointer to error message, or 0 if all ok
|
|
ubyte old_drivenumber
|
|
|
|
sub open(ubyte drivenumber, str filename) -> bool {
|
|
; Open a BMX bitmap file and reads the header information.
|
|
; Returns true if all is ok, false otherwise + error_message will be set.
|
|
error_message = 0
|
|
old_drivenumber = diskio.drivenumber
|
|
diskio.drivenumber = drivenumber
|
|
if diskio.f_open(filename) {
|
|
diskio.reset_read_channel()
|
|
if read_header() {
|
|
if parse_header() {
|
|
if palette_entries>0 {
|
|
if width<=640 {
|
|
return true
|
|
} else
|
|
error_message = "image too large"
|
|
} else
|
|
error_message = "invalid bmx file"
|
|
} ; note: parse_header sets the error message by itself
|
|
} else
|
|
error_message = "invalid bmx file"
|
|
} else
|
|
error_message = diskio.status()
|
|
|
|
close()
|
|
return false
|
|
}
|
|
|
|
sub close() {
|
|
; if you want to close the file before actually loading palette or bitmap data.
|
|
diskio.f_close()
|
|
diskio.drivenumber = old_drivenumber
|
|
}
|
|
|
|
sub continue_load(ubyte vbank, uword vaddr) -> bool {
|
|
; Continues loading the palette and bitmap data from the opened BMX file.
|
|
; Parameters: the vram bank and address where the bitmap data should go.
|
|
; You can set palette_buffer_ptr if you want the palette buffered rather than directly into vram.
|
|
; Note: does not change vera screen mode or colordepth! You have to do that yourself!
|
|
; Returns true if all is ok, false otherwise + error_message will be set.
|
|
error_message = 0
|
|
diskio.reset_read_channel()
|
|
if width==320 or width==640 {
|
|
if compression==0 {
|
|
if read_palette() {
|
|
if not read_bitmap(vbank, vaddr)
|
|
error_message = "bitmap error"
|
|
} else
|
|
error_message = "palette error"
|
|
} else
|
|
error_message = "compression not supported"
|
|
} else
|
|
error_message = "width not 320 or 640" ; note: use continue_load_stamp() to read other sizes
|
|
|
|
close()
|
|
return error_message==0
|
|
}
|
|
|
|
sub continue_load_stamp(ubyte vbank, uword vaddr, uword screenwidth) -> bool {
|
|
; Continues loading the palette and bitmap "stamp" data from the opened BMX file.
|
|
; "Stamp" means: load an image that is smaller than the screen (so we need to pad around it)
|
|
; Parameters:the vram bank and address where the bitmap data should go,
|
|
; and the screen width that the stamp image is loaded into.
|
|
; You can set palette_buffer_ptr if you want the palette buffered rather than directly into vram.
|
|
; Note: does not change vera screen mode or colordepth! You have to do that yourself!
|
|
; Returns true if all is ok, false otherwise + error_message will be set.
|
|
error_message = 0
|
|
diskio.reset_read_channel()
|
|
if compression==0 {
|
|
if read_palette() {
|
|
if not read_bitmap_padded(vbank, vaddr, screenwidth)
|
|
error_message = "bitmap error"
|
|
} else
|
|
error_message = "palette error"
|
|
} else
|
|
error_message = "compression not supported"
|
|
|
|
close()
|
|
return error_message==0
|
|
}
|
|
|
|
sub continue_load_only_palette() -> bool {
|
|
; Continues loading the palette but not the bitmap data from the opened BMX file.
|
|
; You can set palette_buffer_ptr if you want the palette buffered rather than directly into vram.
|
|
; Returns true if all is ok, false otherwise + error_message will be set.
|
|
; Afterwards the file is closed and you can no longer read additional data from it!
|
|
error_message = 0
|
|
diskio.reset_read_channel()
|
|
if not read_palette()
|
|
error_message = "palette error"
|
|
close()
|
|
return error_message==0
|
|
}
|
|
|
|
sub save(ubyte drivenumber, str filename, ubyte vbank, uword vaddr, uword screenwidth) -> bool {
|
|
; Save bitmap and palette data from vram into a BMX file.
|
|
; First you must have set all bmx.* variables to the correct values! (like width, height..)
|
|
; Parameters:
|
|
; drive number and filename to save to,
|
|
; vram bank and address of the bitmap data to save,
|
|
; and optionally the screen width if you want to save a "stamp" that's smaller than the screen.
|
|
; If you're saving the whole screen width, you can leave screenwidth at 0.
|
|
; Returns: success status. If false, error_message points to the error message string.
|
|
error_message = 0
|
|
if compression!=0 {
|
|
error_message = "compression not supported"
|
|
return false
|
|
}
|
|
if screenwidth==0 {
|
|
if width!=320 and width!=640 {
|
|
error_message = "width not 320 or 640"
|
|
return false
|
|
}
|
|
} else {
|
|
if width>screenwidth {
|
|
error_message = "image too large"
|
|
return false
|
|
}
|
|
}
|
|
|
|
old_drivenumber = diskio.drivenumber
|
|
diskio.drivenumber = drivenumber
|
|
if diskio.f_open_w(filename) {
|
|
cx16.r0 = diskio.status()
|
|
if cx16.r0[0]!='0' {
|
|
error_message = cx16.r0
|
|
goto save_end
|
|
}
|
|
diskio.reset_write_channel()
|
|
if write_header() {
|
|
if write_palette() {
|
|
if not write_bitmap(vbank, vaddr, screenwidth)
|
|
error_message = "bitmap error"
|
|
} else
|
|
error_message = "palette error"
|
|
} else
|
|
error_message = "header error"
|
|
} else
|
|
error_message = diskio.status()
|
|
save_end:
|
|
diskio.f_close_w()
|
|
diskio.drivenumber = old_drivenumber
|
|
return error_message==0
|
|
}
|
|
|
|
sub set_bpp(ubyte bpp) {
|
|
ubyte[8] depths = [0,1,1,2,2,2,2,3]
|
|
vera_colordepth = depths[bpp-1]
|
|
bitsperpixel = bpp
|
|
}
|
|
|
|
sub set_vera_colordepth(ubyte depth) {
|
|
vera_colordepth = depth
|
|
bitsperpixel = 1 << depth
|
|
}
|
|
|
|
; ------------------- helper routines, usually not needed to call yourself -------------------------
|
|
|
|
sub read_header() -> bool {
|
|
; load a BMX header from the currently active input file
|
|
for cx16.r0L in 0 to sizeof(header)-1 {
|
|
header[cx16.r0L] = cbm.CHRIN()
|
|
}
|
|
return cbm.READST()==0
|
|
}
|
|
|
|
sub read_palette() -> bool {
|
|
; load palette data from the currently active input file
|
|
; if palette_buffer_ptr is not 0, the palette data is read into that memory buffer,
|
|
; otherwise it is read directly into the palette in vram.
|
|
cx16.vaddr(1, $fa00+palette_start*2, 0, 1)
|
|
cx16.r3 = palette_buffer_ptr
|
|
cx16.r2L = lsb(palette_entries)
|
|
do {
|
|
cx16.r4L = cbm.CHRIN()
|
|
cx16.r4H = cbm.CHRIN()
|
|
if cx16.r3!=0 {
|
|
pokew(cx16.r3, cx16.r4) ; into memory
|
|
cx16.r3+=2
|
|
} else {
|
|
cx16.VERA_DATA0 = cx16.r4L ; into vram
|
|
cx16.VERA_DATA0 = cx16.r4H
|
|
}
|
|
cx16.r2L--
|
|
} until cx16.r2L==0
|
|
return cbm.READST()==0 or cbm.READST()&$40!=0 ; no error or eof?
|
|
}
|
|
|
|
sub read_bitmap_padded(ubyte vbank, uword vaddr, uword screenwidth) -> bool {
|
|
; load bitmap "stamp" into vram from the currently active input file
|
|
cx16.r3 = bytes_per_scanline(width) ; num bytes per image scanline
|
|
cx16.r2 = bytes_per_scanline(screenwidth) ; num bytes per screen scanline
|
|
repeat height {
|
|
cx16.vaddr(vbank, vaddr, 0, 1)
|
|
read_scanline(cx16.r3)
|
|
vaddr += cx16.r2
|
|
if_cs
|
|
vbank++
|
|
}
|
|
return cbm.READST()==0 or cbm.READST()&$40!=0 ; no error or eof?
|
|
}
|
|
|
|
sub read_bitmap(ubyte vbank, uword vaddr) -> bool {
|
|
; load contiguous bitmap into vram from the currently active input file
|
|
cx16.r3 = bytes_per_scanline(width)
|
|
cx16.vaddr(vbank, vaddr, 0, 1)
|
|
repeat height
|
|
read_scanline(cx16.r3)
|
|
return cbm.READST()==0 or cbm.READST()&$40!=0 ; no error or eof?
|
|
}
|
|
|
|
sub read_scanline(uword size) {
|
|
while size!=0 {
|
|
void, cx16.r0 = cx16.MACPTR(min(255, size) as ubyte, &cx16.VERA_DATA0, true)
|
|
if_cs {
|
|
; no MACPTR support
|
|
repeat size
|
|
cx16.VERA_DATA0 = cbm.CHRIN()
|
|
return
|
|
}
|
|
size -= cx16.r0
|
|
}
|
|
}
|
|
|
|
sub write_header() -> bool {
|
|
; save out the BMX header to the currently active output file
|
|
build_header()
|
|
for cx16.r0L in 0 to sizeof(header)-1 {
|
|
cbm.CHROUT(header[cx16.r0L])
|
|
}
|
|
return cbm.READST()==0
|
|
}
|
|
|
|
sub write_palette() -> bool {
|
|
; write palette data to the currently active input file
|
|
; if palette_buffer_ptr is not 0, the palette data is read from that memory buffer,
|
|
; otherwise it is read directly from the palette in vram.
|
|
cx16.r3 = palette_buffer_ptr
|
|
cx16.r2L = lsb(palette_entries)
|
|
cx16.vaddr(1, $fa00+palette_start*2, 0, 1)
|
|
do {
|
|
if cx16.r3!=0 {
|
|
cbm.CHROUT(@(cx16.r3)) ; from memory
|
|
cx16.r3++
|
|
cbm.CHROUT(@(cx16.r3))
|
|
cx16.r3++
|
|
} else {
|
|
cbm.CHROUT(cx16.VERA_DATA0) ; from vram
|
|
cbm.CHROUT(cx16.VERA_DATA0)
|
|
}
|
|
cx16.r2L--
|
|
} until cx16.r2L==0
|
|
return cbm.READST()==0
|
|
}
|
|
|
|
sub write_bitmap(ubyte vbank, uword vaddr, uword screenwidth) -> bool {
|
|
; screenwidth=0: save contiguous bitmap from vram to the currently active output file
|
|
; screenwidth>0: save "stamp" bitmap from vram to the currently active output file
|
|
cx16.vaddr(vbank, vaddr, 0, 1)
|
|
cx16.r3 = bytes_per_scanline(width) ; num bytes per image scanline
|
|
cx16.r2 = 0
|
|
if screenwidth!=0
|
|
cx16.r2 = bytes_per_scanline(screenwidth-width) ; num bytes padding per screen scanline
|
|
repeat height {
|
|
write_scanline(cx16.r3)
|
|
repeat cx16.r2
|
|
cx16.r0L = cx16.VERA_DATA0
|
|
}
|
|
return cbm.READST()==0
|
|
|
|
sub write_scanline(uword size) {
|
|
while size!=0 {
|
|
cx16.r0L = lsb(size)
|
|
if msb(size)!=0
|
|
cx16.r0L = 0 ; 256 bytes
|
|
void, cx16.r0 = cx16.MCIOUT(cx16.r0L, &cx16.VERA_DATA0, true)
|
|
if_cs {
|
|
; no MCIOUT support
|
|
repeat size
|
|
cbm.CHROUT(cx16.VERA_DATA0)
|
|
return
|
|
}
|
|
size -= cx16.r0
|
|
}
|
|
}
|
|
}
|
|
|
|
sub bytes_per_scanline(uword w) -> uword {
|
|
ubyte[4] shifts = [3,2,1,0]
|
|
return w >> shifts[vera_colordepth]
|
|
}
|
|
|
|
sub parse_header() -> bool {
|
|
if header[0]==FILEID[0] and header[1]==FILEID[1] and header[2]==FILEID[2] {
|
|
if header[3]==1 { ; only version 1 supported for now
|
|
bitsperpixel = header[4]
|
|
vera_colordepth = header[5]
|
|
width = peekw(&header+6)
|
|
height = peekw(&header+8)
|
|
palette_entries = header[10]
|
|
if palette_entries==0
|
|
palette_entries=256
|
|
palette_start = header[11]
|
|
; the data offset is not needed: data_offset = peekw(&header+12)
|
|
compression = header[14]
|
|
border = header[15]
|
|
return true
|
|
} else
|
|
error_message = "unsupported bmx file version"
|
|
} else
|
|
error_message = "invalid bmx file"
|
|
|
|
return false
|
|
}
|
|
|
|
sub build_header() {
|
|
; build the internal BMX header structure
|
|
; normally you don't have to call this yourself
|
|
sys.memset(header, sizeof(header), 0)
|
|
uword data_offset = palette_entries*$0002
|
|
data_offset += sizeof(header)
|
|
header[0] = FILEID[0]
|
|
header[1] = FILEID[1]
|
|
header[2] = FILEID[2]
|
|
header[3] = 1 ; version 1
|
|
header[4] = bitsperpixel
|
|
header[5] = vera_colordepth
|
|
header[6] = lsb(width)
|
|
header[7] = msb(width)
|
|
header[8] = lsb(height)
|
|
header[9] = msb(height)
|
|
header[10] = lsb(palette_entries)
|
|
header[11] = palette_start
|
|
header[12] = lsb(data_offset)
|
|
header[13] = msb(data_offset)
|
|
header[14] = compression
|
|
header[15] = border
|
|
}
|
|
}
|