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making one line to reduce size

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Bjorn Einar Bjarntes 2021-12-19 19:41:46 +01:00
parent 3fad901873
commit 5a45ff1c36
1 changed files with 7 additions and 4 deletions
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11
src/main.c
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@ -29,20 +29,23 @@ void setAndClearHiRes(){
setHiRes();
}
void calcAdress(){
ad = 0x2000+((y & 0xf8) << 3) +((y & 0xf8) << 4) +((y & 0xf8) << 4) + (y & 7)+ (x&(0xfff8));
}
BYTE isPositionWhite() {
ad = 0x2000+((y >> 3) << 6) +((y >> 3) << 7) +((y >> 3) << 7) + (y & 7)+ (x&(0xfff8));
calcAdress();
return *(short*)(ad) & 1 << ((7-(x & 7)));
}
// https://archive.org/details/The_Graphics_Book_for_the_Commodore_65/page/n129/
void setPositionWhite() {
ad = 0x2000+ ((y >> 3) << 6) +((y >> 3) << 7) +((y >> 3) << 7) + (y & 7)+(x&(0xfff8));
calcAdress();
*(short*)(ad) = *(short*)(ad) | 1 << ((7-(x & 7)));
}
void setPositionBlack() {
// TODO is it faster to somehow reuse y >> 3 than do it many times, and maybe add the same result twice...
ad = 0x2000+((y >> 3) << 6) +((y >> 3) << 7) +((y >> 3) << 7) + (y & 7)+ (x&(0xfff8));
calcAdress();
*(short*)(ad) = (*(short*)(ad)) & ~(1 << ((7-(x & 7))));
}