Rocks'n'Diamonds

Heya folks,

I recently got back in the kick of Boulder Dash-like games as of late, and one of things that I wanted to bring up is the Emerald Dash levelsets unable to be played normally in Rocks'n'Diamonds through the the Emerald Mine engine. I wasn't sure if this should be under the 'Bug Reports' section, but I feel it's needed since the engine lacks the specific things needed for the Emerald Dash levelsets to play properly, which is what if Emerald Mine has the properties of the Boulder Dash game object logic? Gems being able to harm enemies, amoeba turning into gems if trapped, amoeba turning into rocks if it grew too much, and those special dummy players that if got harmed would also apply to the actual player. Since the Boulder Dash engine has been released, why not address this?

If you go to this link on the search query of 'Emerald Dash' for the YouTube channel, petsasjim1, you'll find some recordings of how they are played, which looks really fascinating.

Some examples of YouTube videos, timestamped:

• https://youtu.be/kYtO1eNyLbc?t=69 - Gems hurting the butterflies, 9 gems that are worth 1 point from that butterfly explosion and no gem worth 3 points, and amoeba being turned into gems...even though they can grow into dirt. This is while playing Emerald Dash 14, level 80.
• https://youtu.be/5IvDQmuo28g?t=51 - Unusual amoeba behavior, seeing the gem dropped into the magic wall makes all the amoeba tiles into gems? This occurs on Emerald Dash 11, level 00.
• https://youtu.be/QL78ckC_2gQ?t=321 - No such thing as Amoeba Drops since it's a Emerald Mine-specific feature, no, this is a Boulder Dash-style Amoeba growth. This happens on Emerald Dash 12, level 03.
• https://youtu.be/QL78ckC_2gQ?t=398 - Amoeba growing too much and all of them becoming boulders instead of gems. This also occurs on Emerald Dash, level 03.
• https://youtu.be/iZ3suOHsktA?t=107 - Dummy player sightings! Couldn't seem to find the dummy players being harmed at the moment. This instance is sighted on Emerald Dash 5, level 00.

The curious thing if this is addressed is how would this be implemented in terms of detecting those particular levelsets that play differently from regular Emerald Mine levelsets? Like a sub-engine within the Emerald Mine engine, as an option in the level editor?

EDIT: Edited the post to include the levelset and level name in each of the listed bulletpoints in the event the YouTube videos might have vanished.

for what it's worth this is also an issue on emeraldmines.net, which uses the same EM engine as RnD: http://emeraldmines.net/play/src/dev.html?disk=99/14

Hi RAP, nice to hear from you again!

And with a great topic! I always wondered about the title screens of the Emerad Dash series:
All things it describes are not supported by the "normal" EM/EMC game engine used by the many EMC disks (or ADFs, when playing in an Amiga emulator), so apparently it is an "exclusive" version of the standard EM/EMC game engine with C64 Boulder Dash modifications. Indeed, this is all not supported by the EM engine in R'n'D.

But I think it could easily be! You have already listed the main differences very well, and playing the original ADFs in emulation should make it fairly easy to check those differences.

The curious thing if this is addressed is how would this be implemented in terms of detecting those particular levelsets that play differently from regular Emerald Mine levelsets? Like a sub-engine within the Emerald Mine engine, as an option in the level editor?

When creating new R'n'D levels using the EM engine, this could indeed be made configurable by a new checkbox to enable those special engine modifications. For existing, old EMC level sets (as part of the EMC collection for R'n'D, which are converted from the original ADF files), the original, native EM/EMC level file format is used. To automatically use those EM engine modifications for BD behavior, I would either have to look for some differences in the level format that indicate that a modified engine has to be used, or add an explicit flag to the "levelinfo.conf" file for all affected level sets (which will only enable the changes when playing with a new game engine version, so existing tapes for thiose level sets (for those levels which are solvable even with vanilla EM/EMC behavior) would still work).

for what it's worth this is also an issue on emeraldmines.net, which uses the same EM engine as RnD: http://emeraldmines.net/play/src/dev.html?disk=99/14

That's true. And -- at least for me -- the browser based version of the engine seems to run with double speed, which makes all those levels quite hard to play.

P.S.: Especially the "dummy player" behavior (if killed, player gets killed, too) seems to be interesting -- the game element used for this seems to be the "spring bumper", so finding Emerald Dash levels that may use this game element with different properties might be easy by checking all those levels in the R'n'D level editor for this specific game element...

Watching more of the YouTube videos, there's some interesting instances of using elements from Emerald Mine within the Emerald Dash levelsets, some within the levels themselves, but most from level 00:

• https://youtu.be/XN9o5PtKxSs?t=605 - Emerald Dash 16, level 01: Acid pool and the associated acid pool tub walls, I wonder if it was in the original levelsets before it got converted, or was there like an acid element in a custom engine or version of Boulder Dash?
• https://youtu.be/9gvkOcxZ5VA?t=162 - Emerald Dash 28, level 00: Keys and doors? That's definitely more Emerald Mine than Boulder Dash stuff!
• https://youtu.be/9gvkOcxZ5VA?t=185 - Emerald Dash 28, level 00: Wha? Magic balls? Using the player character art as the magic ball to spawn those Spaceship-equivalent enemies?
• https://youtu.be/9gvkOcxZ5VA?t=193 - Emerald Dash 28, level 00: Yam yams as well? They 've not been being smashed yet, but the iconic movement is still retained!
• https://youtu.be/9gvkOcxZ5VA?t=202 - Emerald Dash 28, level 00: Even dynamite? Again, Hasn't been used yet, but they're collectible!
• https://youtu.be/pjrPCTKZAao?t=265 - Emerald Dash 31, level 00: Balloons and even the wind direction tile?

Like, really interesting, especially since it's like at the latter half of the whole collection of Emerald Dash, which, I'm surprised there isn't any more Emerald Mine and Boulder Dash levelset hybrids, and the thing is, these Emerald Dash levelsets were the last of the collection in the Emerald Mine Club before things slowed to a trickle and stopped, which again, makes me wonder where all those people involved in the scene nowadays, notably since the organization and the website has long since been gone.

And more sightings of Boulder Dash functionality, beyond the visuals:

• https://youtu.be/XN9o5PtKxSs?t=665 - Emerald Dash 16, level 01: Magic wall changes between boulders and gems, not sequentially like boulder to emerald to diamond and then back to boulder like how it was handled in Emerald Mine.
• https://youtu.be/9gvkOcxZ5VA?t=518 - Emerald Dash 28, level 03: A more clearer instance of the dummy player in action, with the player accidentally revealing the path towards it for the Bug-equivalent enemy to go into it, causing level loss, with the player exploding in a unique explosion radius.
• https://youtu.be/NQqBDvGaVlo?t=309 - Emerald Dash 22, level 01: Curiously, the bugs still retain the chain explosions from Emerald Mine, which definitely wasn't a thing in Boulder Dash.
• https://youtu.be/mmGvA6w0mKo?t=171 - Emerald Dash 04, level 00: Oh, I guess the dummy players don't really die from rocks falling down onto them, or are these magic balls in disguise?
• https://youtu.be/ovssONrPL6s?t=114 - Emerald Dash 20, level 80: Quicksand? Or are these like the slime one from the second Boulder Dash game but it's blue and not green like the amoeba? I think those were randomized whether the rocks fall through, this acts more like Emerald Mine's take of it.

I edited my main post to include the levelset and level number in case the YouTube videos in the unlikely event would've vanished.

Yeah, it would be really neat if these particular set of levelsets would be properly playable, and which again, it would be wild to mix the two stuff together and make a brand new levelset out from this and not relegate it to being Boulder Dash conversion levelsets. This would've been more difficult to document if it weren't for the snapshot videos from that YouTube channel.