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How do you then detect from which side the player "penetrates" the solid object? Do you need a special case if the player penetrates the object exactly from a corner?

Here are few examples: 1. Player jumps while moving left/right and hits the bottom of solid object. You would need to push the player down here. But if you push player on X axis first the player would zip to the side of the solid object. 2. Similar case if player falls while moving left/right and hi...

I mean if object moves diagonally into another object and you want to push the object out, whether you should push the object out in X or Y axis first? If it depends, how do I figure out in which case X is first and when Y? I think having the order wrong can cause incorrect behavior when the code at...

I'm assuming you can also use the distance required for collision to calculate how much the other object needs to be pushed back to not be inside the other object. Since you are checking X and Y separately, does it matter which one you check first? Especially if moving into another object diagonally...

Do these two detection methods have any differences? Like speed or some advantages?

I have been looking into collision detection and found one method where rather than using hitboxes, the code uses a distance to measure if a hit has occurred. The required distance seems to be calculated something like this: pw = width of player's hitbox ow = width of object's hitbox dist_x = ((pw/2...

To my understanding MMC1 is capable of switching the mirroring mode between horizontal and vertical. I don't know what the nametable updates in this game look like during up/down and left/right screen scrolling, but I would guess that it changes the mirroring mode for the scrolling to happen and the...

.charmap seems to be one option, although it's a shame that you can't map characters using .charmap "A",$0A A custom program might work too. I'm not sure if compression algorithms work well on text, but one could be built in the program too. Although you probably need a lot of text to need compress...

When you define a string in cc65 it seems to convert it to bytes according to ASCII table, but I was wondering if there is a way to map the letters to different values. Many NES games have $00-$09 as numbers from 0-9, $0A-$23 as letters from A-Z and some bytes after that as special characters. It wo...

So, these things are used mostly for relocatable code then? I guess they mostly won't be necessary on SNES since the code is at fixed location. By the way, this is a bit off topic, but what do the "Main Screen" and "Sub-Screen" on the SNES actually mean? There seem to be some registers that point to...

I'm not aware of any Mega Man games using 4 name tables. They do mirror name tables in the same direction of the scroll at times, which may leave one of them unused. I did make a mistake there. The game does use only two, but I made a mistake when I looked at the nametable viewer. As for the reset ...

I was looking at Mega Man 6's code and found some pieces of code that don't make sense to me, so I wanted to ask if anyone knows if they actually have any significance. First one is in the reset. It seems to compare one byte to #$08 and then two strings of bytes to see if they are equal. The banks t...

I got back into SNES assembly and I guess the first thing to start is to try to clear few things I haven't been able to find answers to yet. 1. According to this site PEA/PER/PEI instructions push an effective address to stack. What is the point of these instructions and what are some practical uses...

I don't really get the point, but it can still cause incorrectly displayed code if the "BRK operand" is actually the next opcode. In this case a branch jumps over the BRK instruction. The BRK code itself is a JML instruction pointing to itself. I guess the debugger needs a check to see if the byte a...

I was looking through Super Metroid's code and I came across BRK #$9C . To my understanding BRK shouldn't have an operand, so is this a disassembly error in the debugger or is there another reason why it is displayed this way? Also, would it be possible to add options in the debugger to hide RAM and...