Allow the importing and display of BMP files less than 24-bit color depth in bitmapped mode. #17
Description
Enhancement request for Dragon Basic under Linux as of commit ID 7693447
For games which use graphics mode 3 (Bitmapped mode), it would be nice if the user could import and display (Blit) BMP images that are less than 24-bit color depth. The reason being, internally images are converted to 15-bit RGB, so most of that data is unused (While taking up a lot of ROM space). For games like Visual Novels which are heavy in graphics, that could add up quickly. Especially when sharing ROM with music and sound.
Currently it seems like DBC will happily import BMPs that are indexed (256 colors), 16-Bit (R5 G6 B5), and 16-bit (X1 R5 G5 B5), however the Blit function (In bitmapped mode 3) doesn't work with these and displays corrupted output instead. For an idea about the space savings, here is a list:
240x160 Source Image gives...
24bits = 115.3kb
16bits = 76.9kb
8bits (256 colors) = 39.5kb
As you can see, if we had support for blitting 8bit color or even 16bit color in mode 3, we'd have significant ROM space savings.