[SOLVED] [1.11.2] Random leaf colors

[Daeruin]

I'm attempting to add seasons to my mod. I thought I was being clever by registering a new block color handler for vanilla leaves that randomizes the leaf color, so every leaf block has a different color. Each season has its own palette of colors to choose randomly from. The fall leaves look fantastic! I update the leaf block colors every time the season changes by forcing Minecraft to reload the renderers, via RenderGlobal#loadRenderers, in a ClientTickEvent.

 

The issue I didn't foresee is that leaves tend to change color randomly all throughout the day, even without me reloading the renderers. I guess there's something in the client that's trying to look up the block color at certain points. I'm not sure what it is. Was my idea just a bad one? Or is there some way to salvage it? Maybe there's some way for me to ensure the same "random" color is always chosen within the same season for a given block? Or store which color is chosen somehow?

 

Code (I chopped out some of the seasons enum for brevity):

 

Spoiler

        blockColors.registerBlockColorHandler(new IBlockColor()
        {
            @Override
            public int colorMultiplier(IBlockState state, @Nullable IBlockAccess blockAccess, @Nullable BlockPos pos, int tintIndex)
            {
                if (blockAccess == null || pos == null)
                {
                    return ColorizerFoliage.getFoliageColorBasic();
                }

                BlockPlanks.EnumType leafType = state.getValue(BlockOldLeaf.VARIANT);
                PrimalTime.Month month = PrimalTime.getMonth(MINECRAFT.world.getTotalWorldTime());

                return month.getRandomLeafColor(leafType);
            }
        }, Blocks.LEAVES);

 

    public enum Month
    {
        EARLY_SPRING("Early Spring", new int[]{13693083, 8235823, 9093906, 11461411, 16046127}, new int[]{16643845, 13360128, 15857547, 11516964, 11703159}, new int[]{5478471, 1402894, 4680230, 5536279}, new int[]{10788864, 15522940, 8795965, 9341257, 16119796}, new int[]{10599766, 10270732, 12439591, 15790414, 14671277}),
        MID_SPRING("Mid-Spring", new int[]{8624642, 13031424, 16769285, 16772867, 16046127}, new int[]{16643845, 13360128, 15857547, 11516964, 6795023}, new int[]{1402894, 2573336, 2638875, 4680230, 5536279}, new int[]{14418458, 11547439, 15121083, 8795965, 10788864}, new int[]{10599766, 10270732, 7460875, 6603561, 15790414});

        private final String monthName;
        private int[] acaciaLeafColors;
        private int[] birchLeafColors;
        private int[] darkOakLeafColors;
        private int[] jungleLeafColors;
        private int[] oakLeafColors;
        private Random random = new Random();

        Month(String monthName, int[] acaciaLeafColors, int[] birchLeafColors, int[] darkOakLeafColors, int[] jungleLeafColors, int[] oakLeafColors)
        {
            this.monthName = monthName;
            this.acaciaLeafColors = acaciaLeafColors;
            this.birchLeafColors = birchLeafColors;
            this.darkOakLeafColors = darkOakLeafColors;
            this.jungleLeafColors = jungleLeafColors;
            this.oakLeafColors = oakLeafColors;
        }

        @Override
        public String toString()
        {
            return this.monthName;
        }

        public String getNameByIndex(int index)
        {
            return Month.values()[index].toString();
        }

        public int getRandomLeafColor(BlockPlanks.EnumType leafType)
        {
            if (leafType == BlockPlanks.EnumType.ACACIA)
                return this.acaciaLeafColors[random.nextInt(acaciaLeafColors.length)];
            else if (leafType == BlockPlanks.EnumType.BIRCH)
                return this.birchLeafColors[random.nextInt(birchLeafColors.length)];
            else if (leafType == BlockPlanks.EnumType.DARK_OAK)
                return this.darkOakLeafColors[random.nextInt(darkOakLeafColors.length)];
            else if (leafType == BlockPlanks.EnumType.JUNGLE)
                return this.jungleLeafColors[random.nextInt(jungleLeafColors.length)];
            else if (leafType == BlockPlanks.EnumType.OAK)
                return this.oakLeafColors[random.nextInt(oakLeafColors.length)];
            else if (leafType == BlockPlanks.EnumType.SPRUCE)
            {
                return ColorizerFoliage.getFoliageColorPine();
            }
            else
                return ColorizerFoliage.getFoliageColorBasic();
        }

    }

 

 

Edited January 30, 2018 by Daeruin
Marking solved.

[Draco18s]

I do it like this in one of my mods:

Random r = new Random(pos.toLong());

[Daeruin]

That seems to have done the trick! I thought it might be something along those lines. +1 knowledge.

[Daeruin]

OK, one wrinkle with this, I guess because of how the math works out. If I only provide four leaf colors to choose randomly from, and use the BlockPos as the random seed, every block along the same Z axis ends up the same color. Easily solved by providing one extra color, but something to be aware of if someone is reading this later.

[Draco18s]

1 hour ago, diesieben07 said:

Check out MathHelper.getPositionRandom. It does some bit-mangling to avoid issues like this.

Oh cool, I'll start using this. I don't think my usage had an observable pattern like that, but I didn't know this existed.

[Daeruin]

Yep, using that method does indeed make the issue go away. I used it like this:

 

Random random = new Random(MathHelper.getPositionRandom(pos));

[Daeruin]

Thank you for the correction. I misunderstood.

[Daeruin]

I should not be trying to code when it's this late. I need to choose randomly among four or five options. getPositionRandom returns a long. I don't understand what it's doing to generate the random number, or if it could potentially generate a negative number. But I guess I need to do some maths like this?

 

Math.abs(MathHelper.getPositionRandom(pos)) % 5;

 

[Draco18s]

9 hours ago, Daeruin said:

I should not be trying to code when it's this late. I need to choose randomly among four or five options. getPositionRandom returns a long. I don't understand what it's doing to generate the random number, or if it could potentially generate a negative number. But I guess I need to do some maths like this?

 

Math.abs(MathHelper.getPositionRandom(pos)) % 5;

 

Yep, that's sufficient. There may be a (very small) bias, but it's not worth worrying about.

[Daeruin]

Now that I'm doing it right, there is still a noticeable pattern: the colors form a 4x4 grid along the Y axis. However, it isn't that big of a deal since I decided I want to add more colors anyway.

[Draco18s]

Yeah I had that problem in 1.7 (where I did my own randomization) before finding a satisfactory result.  And I was working with 11 different sprites!

[Draco18s]

On 1/31/2018 at 7:53 AM, diesieben07 said:

Check out MathHelper.getPositionRandom. It does some bit-mangling to avoid issues like this.

Turns out that MathHelper.getPositionRandom is SideOnly(CLIENT), which makes it (directly) unusable for me.

Ah, but that's just a wrapper function to getCoordinateRandom, which isn't sided. OTOH, I pass my Random instance into a method to get a random position within a circle, followed by several other random calls for a few other things,* so I do actually need a full random instance.

 

*I get the unit circle, multiple by a radius, offset this from the original position, then make up to 8 more [random inside-unit-circle] * [smaller distance] polls, in order to create a randomly placed tight cluster of flowers (plus sometimes I need a boolean random for if the plant can be two-blocks-tall).