 Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me. |
Forum Index : Microcontroller and PC projects : Bitmap colour depth
| Author | Message | ||||
thwill Guru  Joined: 16/09/2019 Location: United KingdomPosts: 4036 |
Hey folks, I don't suppose anyone has a set of .bmp files in the various colour depths supported by MMBasic (black & white, 4-bit, 4-bit compressed, 8-bit colour, 8-bit greyscale, 16-bit and 24-bit) ? I'd like to write a test of this functionality for MMB4L. Yes, I know I should be able to just find and download this sort of thing from the internet, but I'm finding that much more difficult than I expected. Best wishes, Tom Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
||||
phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2135 |
Something like this could generate the test images for you. It is similar to the one by @Sasquatch in another thread but reads back the valid primary colours and saves the BMP. It should be possible to expand it to also do mixed colours. 'A display colour counter Clear : Option Base 0 Dim String S$(2) = (" Blues", " Greens", " Reds") Dim Integer a, b, c, d For a = 0 To 2 'cycle through blue, green, red b = 0 'initialize colour count For c = 0 To 255 'set the brightness d = c << (a * 8) 'make a 24bit colour Line c+9, 9+50*a, c+9, 45+50*a, 1, d 'send it to a line If d = Pixel(c+9, 20+50*a) Then 'read that pixel back from the screen Inc b 'if the colour is the same as the one sent count it Print d>>16, (d>>8) And 255, d And 255 'Show the RGB values for the matching colour EndIf Next Print b; S$(a) 'show counted colours Next Save image "colour counter.bmp", 1,1,266,150 End Edited 2024-09-03 17:45 by phil99 |
||||
| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4036 |
Thanks Phil, but SAVE IMAGE always saves in the 24-bit true colour .bmp format. I'm looking for images in all the .bmp sub-formats that MMBasic supports. However I've since found: https://sourceforge.net/projects/bmptestsuite/ Thanks, Tom Edited 2024-09-03 17:48 by thwill Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
||||
| phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2135 |
Ok, my mistake I tested on an ILI9431 and the 2040 PicoVGA which are not the same as a 2350. |
||||
| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4036 |
I don't have a 2350 ... no distractions until I heave the new alpha for MMB4L over the wall. But in any case I'm 99% certain the hardware PicoMite/VGA/CMM2 and display is irrelevant (except that display which doesn't support read), the MMBasic SAVE IMAGE command always saves a 24-bit true colour image, even if all the pixels are black. Best wishes, Tom Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
||||
| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4222 |
Sorry Tom, not true. If you show an image in mode2 on a PicoMiteVGA, and SAVE IMAGE, you get a BMP files that is 38kbyte size. This is 4bpp. If you SAVE COMPRESSED IMAGE, you get a BMP file that is (depending the content) few kB...40kB in size. Also in 4bpp. I use this function, to convert a 24bpp BMP file (created in any package) to a smaller size 4bpp BMP file (like for PETSCII robots). A 320x240 24bpp BMP file is 250kbyte in size. This is different from LCD. The LCD version saves in 24bpp. Maybe this difference should be added to the PicoMiteVGA user manual, since it is quite essential. 4bpp imgae, and compressed 4bpp image. flappy.zip This is the type of image in the zip  Volhout Edited 2024-09-03 21:10 by Volhout PicomiteVGA PETSCII ROBOTS |
||||
| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4036 |
Thanks @Volhout very useful, the manual certainly says the former is saving a 24-bit true colour image, I also wonder if I've been led astray by the CMM2 code or am just "making sh*t up"  .Tom Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
||||
| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4222 |
PicomiteVGA PETSCII ROBOTS |
||||
| phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 2135 |
Saving an image from a LCD screen also has the colours reduced to that of the screen. Eg 24 bits per pixel are sent to an ILI9488 but the saved image has 18 b/P. The colour counter program shows the 2 LS bits are missing from each colour. That and the saved images from the PicoMiteVGA is why I thought the 2350 would do the same thing. |
||||
| thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4036 |
I do not believe that there is an 18-bit .bmp standard so suspect what is being saved to the file is 24-bit true colour. I'm guessing that MMBasic (at least on that platform) is only reading and writing 18-bits to the display, you can provide more bits in your RGB but the 2 LS bits are always being discarded. Try using the PIXEL command to plot some "Red" with the 2 LS bits set and then the PIXEL() function to read it back, I wouldn't be surprised if the 2 LS bits are unset in the returned value. Note that I'm fairly certain that 2350 vs. 2040 has nothing to do with anything; I believe the MMBasic firmware for both is the same in this area. Best wishes, Tom Edited 2024-09-03 23:49 by thwill Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
||||
stanleyella Guru Joined: 25/06/2022 Location: United KingdomPosts: 2120 |
how I did my first sprites pico mmbasic 2 years ago CONST bk = RGB(BLack) const wh = rgb(white) const bl = rgb(blue) const gr = rgb(green) const cy = rgb(cyan) const re = rgb(red) const ma = rgb(magenta) const ye = rgb(yellow) const br = rgb(brown) ' restore cls udg1 'draws sprite1 on screen at 10,10 BLIT READ 1,10,10,16,16 'reads sprite1 from screen to blit buffer1 udg1 'draws sprite2 on screen at 10,10 blit read 2,10,10,16,16 'reads sprite2 from screen to blit buffer2 cls blit read 3,10,10,16,16 'reads 16x16 background to blit buffer3 sub udg1 'draws 16x16 data for blit to copy for spht%=0 to 15 for spw%=0 to 15 read sp1% pixel spw%+10,spht%+10,sp1% next spw% next spht% end sub 'sprite1 data wh,bl,bl,bl,bl,bk,bk,bk,bk,bk,bk,bl,bl,bl,bl,wh data bk,bl,re,re,re,bl,bl,bk,bk,bl,bl,re,re,re,bl,bk data bk,bk,bk,bl,re,wh,bl,bk,bk,bl,wh,re,bl,bk,bk,bk data bk,bk,bk,bl,re,wh,bl,bk,bk,bl,wh,re,bl,bk,bk,bk data bk,bk,bk,bk,bl,wh,bl,bk,bk,bl,wh,bl,bk,bk,bk,bk data bk,bk,bk,bk,bk,bl,bl,bk,bk,bl,bl,bk,bk,bk,bk,bk data bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk data bk,bk,bk,bk,ye,ye,ye,bk,bk,ye,ye,ye,bk,bk,bk,bk data bk,bk,bk,ye,bk,bk,bk,bk,bk,bk,bk,bk,ye,bk,bk,bk data bk,ye,ye,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,ye,ye,bk data bk,ye,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,ye,bk data ye,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bl,ye data ye,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,ye data ye,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,ye data bk,ye,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,ye,bk data bk,bk,ye,bk,bk,bk,bk,bk,bk,bk,bk,bk,bk,ye,bk,bk it's so basic a way of creating a sprite, if I could add the colours to the abbreviations you'd see the sprite Edited 2024-09-04 05:03 by stanleyella |
||||
 Print this page |
