The title pretty much says it. I've already managed to detect if the player is right clicking on a water source block. To do that, I use the following code to get a RayTraceResult, then check if the block at that position is equal to Blocks.WATER.

 

RayTraceResult code:

Spoiler

    private static RayTraceResult getRayTraceResultFromPlayer(World world, EntityLivingBase entity)
    {
        int reach = 4;
        float var4 = 1.0F;
        float pitch = entity.prevRotationPitch + (entity.rotationPitch - entity.prevRotationPitch) * var4;
        float yaw = entity.prevRotationYaw + (entity.rotationYaw - entity.prevRotationYaw) * var4;
        double posX = entity.prevPosX + (entity.posX - entity.prevPosX) * var4;
        double posY = entity.prevPosY + (entity.posY - entity.prevPosY) * var4 + 1.62D - entity.getYOffset();
        double posZ = entity.prevPosZ + (entity.posZ - entity.prevPosZ) * var4;
        Vec3d vec = new Vec3d(posX, posY, posZ);
        float var14 = MathHelper.cos(-yaw * 0.017453292F - (float) Math.PI);
        float var15 = MathHelper.sin(-yaw * 0.017453292F - (float) Math.PI);
        float var16 = -MathHelper.cos(-pitch * 0.017453292F);
        float var17 = MathHelper.sin(-pitch * 0.017453292F);
        float var18 = var15 * var16;
        float var20 = var14 * var16;

        Vec3d var23 = vec.addVector(var18 * reach, var17 * reach, var20 * reach);
        return world.rayTraceBlocks(vec, var23, true);
    }

 

 

However, when the player right clicks on flowing water, the ray trace does not detect it at all and instead detects the block immediately past the flowing water.

 

It seems like maybe the fault is in BlockLiquid#canCollideCheck, which returns false if the water level is anything other than 0 (not flowing). That method is used by World#rayTraceBlocks, which I'm using in my ray trace code. Is there a another way?

17 hours ago, Daeruin said:

However, when the player right clicks on flowing water, the ray trace does not detect it at all and instead detects the block immediately past the flowing water.

Try

world.rayTraceBlocks(vec1, vec2, true, false, true)

 

Thanks for the suggestion. I tried the parameters you suggested. It only seems to return the flowing water block (with a hit type of MISS) if there's no other block in range. If I'm close to the flowing water, it still returns the block behind the flowing water. I'm thinking I might need to do a custom ray trace.

After copying World#rayTraceBlocks into my PlayerInteractEvent and messing around a bit, I can now say that the culprit was indeed BlockLiquid#canCollideCheck. It returns false if the block's level is anything other than 0 (full source water block) and prevents the ray trace from returning the flowing water block as a hit. So I just need to bypass that in my copy of World#rayTraceBlocks, and the ray trace now returns flowing water blocks.