04. Full background

Under construction.

Writing a full screen as a RLE compressed file.

I wrote another blog page, a while back, about importing a BMP file into NES Screen Tool. Here…

https://nesdoug.com/2017/04/22/nes-screen-tool-bmp-import/

I’m using the same graphics (Girl3.chr), and I’ve saved my NES Screen Tool (.nss) file as a compressed rle file, “Nametable/Save Nametable and Attributes/RLE packed as C header .h”. Now we can import it into the C code, and print it to the background.

A full nametable is 1024 bytes. We can’t do this with the screen on, so turn it off, then set a starting address, and call the rle function.

ppu_off();

vram_adr(NAMETABLE_A);

vram_unrle(Girl3);

ppu_on_all();

So far, I’ve forgotten to mention the palette. I had to change it to make it brown shades. I’m going to discuss this in more detail later. pal_bg() sets the palette for the BG.

04_fullBG

https://github.com/nesdoug/04_FullBG/blob/master/fullBG.c

https://github.com/nesdoug/04_FullBG

.

neslib makes it easy to change the brightness of the screen. You can do this with pal_bright(), using a value between 0 (black) and 8 (white). 4 = normal.

I borrowed a function from Shiru’s “Chase” game, and it’s very easy to use.

pal_fade_to(0,4); // fade from black to normal

pal_fade_to(4,0); // fade from normal to black

https://github.com/nesdoug/05_Fade/blob/master/fade.c

https://github.com/nesdoug/05_Fade

 

 

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