-- ===================================================================

-- Welcome to the Minetest Water API.

-- We'd like to avoid adding APIs that create a  huge number of nodes,
-- as RealTest did,  or ones that slows things down, as the Clouds API
-- did.

-- This said,  the Water API  creates  complex data structures  but is
-- quite useful. It greatly simplifies the process of adding new types
-- of water to the "_game".

-- One call sets up all of the following:
--
--    * Water Source and Flowing nodes
--    * Water Gel and Slope nodes
--    * Buckets for the bucket-able nodes
--
-- plus these configurable parameters and/or modes:
--
--    * Optional lighting (a)
--    * Optional damage   (a)
--    * Optional drowning (a)
--    * Viscosity         (a)
--    * Flow range        (b)
--    * Renewable         (b)
--    * Allow water source in creative inventory or not
--    * Conversion of water source by buckets into gel form
--
-- (a) Can be different for normal water and gel forms
-- (b) Doesn't apply to gels

-- The water API automatically  builds  full-bucket images  that match
-- each water type. The images look correct both in inventory and when
-- a bucket is wielded.

-- Three ".png" image files are required for each water type:
--
-- default_red_punch.png
-- default_red_punch_source_animated.png
-- default_red_punch_flowing_animated.png
--
-- These files use the same icon,  source animated, and flowing anima-
-- ted formats that were used for standard Minetest water nodes in the
-- past.

-- Most  settings are illustrated in the  sample definitions block be-
-- low. There is one related "world.conf" setting:
--
-- bucket_gels_water = true
--
-- If the preceding setting is used,  putting a water source node into
-- a bucket will convert it to the corresponding type of gel.

-- ===================================================================

-- local defs = {
--     -- Regular water: 160
--     -- Thicker water: 200
--     alpha             = 200           ,
--
--     -- Omit these to suppress lighting
--     -- Or set them to integer lighting values
--     -- Settings of -1 trigger maximum brightness
--     -- "light" sets both "light_..." at once
--     --
--     light_gel         = -1            ,
--     light_normal      = -1            ,
--     light             = -1            ,
--
--     -- Base name: Lower case, no spaces.
--     basename          = "red_punch"   ,
--
--     -- Standard MT water source  animation table
--     animation_source  = {
--         type     = "vertical_frames"  ,
--         aspect_w = 16                 ,
--         aspect_h = 16                 ,
--         length   =  2.0               ,
--     } ,
--
--     -- Standard MT water flowing animation table
--     animation_flowing = {
--         type     = "vertical_frames"  ,
--         aspect_w = 16                 ,
--         aspect_h = 16                 ,
--         length   =  0.8               ,
--     } ,
--
--     -- "a" is post-effect alpha setting
--     -- "r", "g", "b" are RGB integers ranging from 0 to 255
--     --
--     post_effect_color = { a=180, r=150, g=30, b=30 }
-- }

-- The preceding table plus the following call is all that's needed:
--
-- default.register_water (defs)

-- ===================================================================

-- The "animation_source" parameter is optional.  If it's omitted, the
-- default table used is:
--
-- animation_source = default.base_water_animation_source
--
-- which provides the "animation_source" settings listed in the sample
-- definitions block above.

-- For the default table to work, the animation-source image used must
-- be derived from the Final MT version of:
--
-- default_water_source_animated.png

-- ===================================================================
-- The "animation_flowing" parameter is optional. If it's omitted, the
-- default table used is:
--
-- animation_flowing = default.base_water_animation_flowing
--
-- which provides the  "animation_flowing" settings listed in the sam-
-- ple definitions block above.

-- For the default table  to work,  the  animation-flowing image  used
-- must be derived from the Final MT version of:
--
-- default_water_flowing_animated.png

-- ===================================================================

-- If no "groups" table is provided in the definitions table,  "regis-
-- ter_water"  uses the following default "groups" attributes for nor-
-- mal water:
--
-- groups = {
--     water=3, liquid=3, puts_out_fire=1,
--     not_in_creative_inventory=1
-- } ,
--
-- and the following default "groups" attributes for gel forms:
--
-- groups = { water=3, liquid=3, puts_out_fire=1, water_gel=1 } ,

-- If you'd like normal water to be in the creative inventory, you can
-- add the following setting to the definitions table:
--
-- creative=1 ,
--
-- or you can specify  "groups" explicitly  and set  "not_in_creative_
-- inventory" to 0 in "groups".

-- Presently, gels  are  in the  creative inventory  regardless of any
-- "creative" or "not_in_creative_inventory" setting.

-- ===================================================================

-- The following parameters are optional but may be set in the defini-
-- tions table as well:

-- damage_gel       = 3 -- Gel          damage/second  (default: 0)
-- damage_normal    = 3 -- Normal water damage/second  (default: 0)
-- damage           = 3 -- Sets the preceding two at once

-- drowning_gel     = 0 -- Gel          drowning       (default: 1)
-- drowning_normal  = 0 -- Normal water drowning       (default: 1)
-- drowning         = 0 -- Sets the preceding two at once

-- viscosity_gel    = 3 -- Gel          viscosity      (default: 1)
-- viscosity_normal = 3 -- Normal water viscosity      (default: 1)
-- viscosity        = 3 -- Sets the preceding two at once

-- These parameters don't apply to gels:
--
-- range            = 2     -- Flow range       (default: engine)
-- renewable        = false -- "renewable" flag (default: engine)
-- liquid_range     = 2     -- Same as "range"
-- liquid_renewable = false -- Same as "renewable"

-- ===================================================================

default.waters = {}

default.base_water_animation_source = {
    type     = "vertical_frames"  ,
    aspect_w = 16                 ,
    aspect_h = 16                 ,
    length   =  2.0               ,
}

default.base_water_animation_flowing = {
    type     = "vertical_frames"  ,
    aspect_w = 16                 ,
    aspect_h = 16                 ,
    length   =  0.8               ,
}

-- ===================================================================

function default.register_water (defs)

    local str
    local defs = ocutil.clone_table (defs)

-- ===================================================================

    -- "basename" is required
    if defs.basename == nil then return end

    -- E.g. "red_punch", "river_water", "water"
    local base         = defs.basename

    local imgbase =  defs.imgbase
    if    imgbase == nil then imgbase = base end

    local base_png     = "default_" .. imgbase .. ".png"
    local base_source  = imgbase .. "_source"
    local base_flowing = imgbase .. "_flowing"

    local node_source  = "default:" .. base .. "_source"
    local node_flowing = "default:" .. base .. "_flowing"
    local node_gel     = "default:" .. base .. "_gel"
    local node_slope   = node_gel   .. "_slope"

-- ===================================================================

    if defs.animation_source  == nil then
       defs.animation_source  =  default.base_water_animation_source
    end

    if defs.animation_flowing == nil then
       defs.animation_flowing =  default.base_water_animation_flowing
    end

-- ===================================================================

    if defs.alpha            == nil then
       defs.alpha            = 160
    end

-- ===================================================================

    if defs.damage_normal    == nil then
       defs.damage_normal    = defs.damage
    end

    if defs.damage_gel       == nil then
       defs.damage_gel       = defs.damage
    end

-- ===================================================================

    if defs.light_normal     == nil then
       defs.light_normal     = defs.light
    end

    if defs.light_gel        == nil then
       defs.light_gel        = defs.light
    end

-- ===================================================================

    if defs.liquid_range     == nil then
       defs.liquid_range     = defs.range
    end

    if defs.liquid_renewable == nil then
       defs.liquid_renewable = defs.renewable
    end

-- ===================================================================

    if defs.drowning         == nil then
       defs.drowning         = 1
    end

    if defs.drowning_normal  == nil then
       defs.drowning_normal  = defs.drowning
    end

    if defs.drowning_gel     == nil then
       defs.drowning_gel     = defs.drowning
    end

-- ===================================================================

    if defs.viscosity        == nil then
       defs.viscosity        =  1
    end

    if defs.viscosity_normal == nil then
       defs.viscosity_normal =  defs.viscosity
    end

    if defs.viscosity_gel    == nil then
       defs.viscosity_gel    =  defs.viscosity
    end

-- ===================================================================

    local maxlight = default.LIGHT_MAX-1

    if defs.light_normal     ~= nil and
       defs.light_normal > maxlight then
       defs.light_normal = maxlight
    end
    if defs.light_gel       ~= nil and
       defs.light_gel    > maxlight then
       defs.light_gel    = maxlight
    end
    if defs.light_normal     ~= nil and
       defs.light_normal < 0        then
       defs.light_normal = maxlight
    end
    if defs.light_gel       ~= nil and
       defs.light_gel    < 0       then
       defs.light_gel    = maxlight
    end

-- ===================================================================

    if defs.ucname           == nil then
        str = base
        str = string.upper (str:sub (1,1)) .. str:sub (2)
        str = string.gsub (str, "_", " ")
        str = string.gsub (str, " punch", " Punch")
        str = string.gsub (str, " water", " Water")
        defs.ucname = str
    end

    default.waters [base] = defs.ucname

-- ===================================================================

    if  defs.groups          == nil then
        defs.groups = { water=3, liquid=3, puts_out_fire=1 }
    end

    defs.groups_normal = ocutil.clone_table (defs.groups)
    defs.groups_gel    = ocutil.clone_table (defs.groups)

-- ===================================================================
-- Fix a misplaced "creative=...".

    if  defs.groups_normal.creative ~= nil then
        defs.creative =
        defs.groups_normal.creative
        defs.groups_normal.creative =  nil
        defs.groups_gel.creative    =  nil
    end

-- ===================================================================

    defs.groups_gel.not_in_creative_inventory = nil
    if  defs.creative == nil then defs.creative = false end

    if  defs.creative ~= 1 and defs.creative ~= true and
        defs.groups_normal.not_in_creative_inventory == nil then
        defs.groups_normal.not_in_creative_inventory = 1
    end

-- ===================================================================

    if  defs.post_effect_color == nil then
        defs.post_effect_color = { a=103, r=60, g=60, b=60 }
    end

-- ===================================================================

    local amtiles_source = {
        name             = "default_" .. base_source
                                      .. "_animated.png" ,
        backface_culling = false                         ,
        animation        = defs.animation_source
    }

-- ===================================================================

    minetest.register_node (node_source, {

        description       = defs.ucname .. " Source"    ,
        alpha             = defs.alpha                  ,
        light_source      = defs.light_normal           ,
        paramtype         = "light"                     ,

        tiles             = { amtiles_source }          ,
        special_tiles     = { amtiles_source }          ,

        buildable_to      = true                        ,
        diggable          = false                       ,
        is_ground_content = false                       ,
        pointable         = false                       ,
        walkable          = false                       ,

        damage_per_second = defs.damage_normal          ,
        drop              = ""                          ,
        drowning          = defs.drowning_normal        ,
        groups            = defs.groups_normal          ,
        post_effect_color = defs.post_effect_color      ,

        drawtype          = "liquid"                    ,
        liquidtype        = "source"                    ,
        liquid_range      = defs.liquid_range           ,
        liquid_renewable  = defs.liquid_renewable       ,
        liquid_viscosity  = defs.viscosity_normal       ,

        liquid_alternative_flowing = node_flowing       ,
        liquid_alternative_source  = node_source        ,
    })

-- ===================================================================

    local amtiles_flowing_bc0 = {
        name             = "default_" .. base_flowing
                                      .. "_animated.png" ,
        backface_culling = false                         ,
        animation        = defs.animation_flowing
    }

    local                   amtiles_flowing_bc1 =
        ocutil.clone_table (amtiles_flowing_bc0)
    amtiles_flowing_bc1.backface_culling = true

-- ===================================================================

    minetest.register_node (node_flowing, {

        description       = "Flowing " .. defs.ucname   ,
        alpha             = defs.alpha                  ,
        light_source      = defs.light_normal           ,
        paramtype         = "light"                     ,
        paramtype2        = "flowingliquid"             ,

        tiles             = { base_png }                ,
        special_tiles     = {
            amtiles_flowing_bc0 ,
            amtiles_flowing_bc1 ,
        } ,

        buildable_to      = true                        ,
        diggable          = false                       ,
        is_ground_content = false                       ,
        pointable         = false                       ,
        walkable          = false                       ,

        damage_per_second = defs.damage_normal          ,
        drop              = ""                          ,
        drowning          = defs.drowning_normal        ,
        groups            = defs.groups_normal          ,
        post_effect_color = defs.post_effect_color      ,

        drawtype          = "flowingliquid"             ,
        liquidtype        = "flowing"                   ,
        liquid_range      = defs.liquid_range           ,
        liquid_renewable  = defs.liquid_renewable       ,
        liquid_viscosity  = defs.viscosity_normal       ,

        liquid_alternative_flowing = node_flowing       ,
        liquid_alternative_source  = node_source        ,
    })

-- ===================================================================

-- For standard types of water:

-- Water Gel resembles water, but it neither flows nor  generates more
-- water. It can be picked up and moved using a bucket.

-- By default, the only source for Water Gel is WorldEdit. However, if
-- you add the following setting to "world.conf":
--
-- bucket_gels_water = true
--
-- Water Source  that is placed in a  bucket will turn into Water Gel.
-- Some world hosts may prefer this mode as an anti-griefing measure.

-- ===================================================================

    minetest.register_node (node_gel, {

        description       = defs.ucname .. " Gel"       ,
        alpha             = defs.alpha                  ,
        light_source      = defs.light_gel              ,
        paramtype         = "light"                     ,

        tiles             = { amtiles_source }          ,
        special_tiles     = { amtiles_source }          ,

        buildable_to      = true                        ,
        diggable          = false                       ,
        is_ground_content = false                       ,
        pointable         = false                       ,
        walkable          = false                       ,

        damage_per_second = defs.damage_gel             ,
        drop              = ""                          ,
        drowning          = defs.drowning_gel           ,
        groups            = defs.groups_gel             ,
        post_effect_color = defs.post_effect_color      ,

        drawtype          = "liquid"                    ,
        liquidtype        = "source"                    ,
        liquid_range      = 0                           ,
        liquid_renewable  = false                       ,
        liquid_viscosity  = defs.viscosity_gel          ,

        liquid_alternative_flowing = node_gel           ,
        liquid_alternative_source  = node_gel           ,
    })

-- ===================================================================

-- For standard types of water:

-- Water Gel Slope,  like Water Gel,  is an alternative  type of water
-- used for anti-griefing and/or building purposes.  Also  like  Water
-- Gel, this type of water doesn't flow.

-- Water Gel Slope  is used with Water Gel  but  it  doesn't come from
-- Water Gel. Presently, it comes only from WorldEdit, but it could be
-- added to Creative or possibly to crafting recipes.

-- This node can be picked up and moved using a bucket.

-- The  purpose of Water Gel Slope  is to add slopes  to the  edges of
-- structures  made  out of Water  Gel cubes.  If a Water Gel Slope is
-- placed next to a Water Gel cube,  the Slope  connects  in a natural
-- manner to the cube.

-- ===================================================================

    minetest.register_node (node_slope, {

        description       = defs.ucname .. " Gel Slope" ,
        light_source      = defs.light_gel              ,
        paramtype         = "light"                     ,

        tiles             = { base_png }                ,
        special_tiles     = {
            amtiles_flowing_bc0 ,
            amtiles_flowing_bc1 ,
        } ,

        buildable_to      = true                        ,
        diggable          = true                        ,
        is_ground_content = false                       ,
        pointable         = true                        ,
        walkable          = false                       ,

        damage_per_second = defs.damage_gel             ,
        drop              = node_slope                  ,
        drowning          = defs.drowning_gel           ,
        groups            = defs.groups_gel             ,
        post_effect_color = defs.post_effect_color      ,

        drawtype          = "flowingliquid"             ,
        liquidtype        = "liquid"                    ,
        liquid_range      = 0                           ,
        liquid_renewable  = false                       ,
        liquid_viscosity  = defs.viscosity_gel          ,

        liquid_alternative_flowing = node_slope         ,
        liquid_alternative_source  = node_gel           ,
    })
end

-- ===================================================================

local defs = {}

-- ===================================================================
-- Set up regular water.

defs = {
    alpha             = 160            ,
    basename          = "water"        ,
    light_gel         = -1             ,
    post_effect_color = { a=103, r=30, g=60, b=90 } ,
}

default.register_water (defs)

-- ===================================================================
-- Set up River Water.

defs = {
    alpha             = 160            ,
    basename          = "river_water"  ,
    liquid_range      = 2              ,
    liquid_renewable  = false          ,
    post_effect_color = { a=103, r=30, g=76, b=90 } ,
}

default.register_water (defs)

-- ===================================================================
-- Set up Sewer Water.

defs = {
    alpha             = 160            ,
    basename          = "sewer_water"  ,
    imgbase           = "brown_punch"  ,
    light             = 4              ,
    ucname            = "Sewer Water"  ,
    post_effect_color = { a=103, r=40, g=20, b=0 } ,
}

default.register_water (defs)

-- ===================================================================
-- Set up Toxic Waste.

defs = {
    alpha             = 160            ,
    basename          = "toxic_waste"  ,
    damage            =  1             ,
    imgbase           = "green_punch"  ,
    light             = -1             ,
    ucname            = "Toxic Waste"  ,

    groups = {
        water=3, liquid=3,
        toxic_waste=1,
        not_in_creative_inventory=1
    } ,

    post_effect_color = { a=180, r=30, g=150, b=30 } ,
}

default.register_water (defs)

-- ===================================================================
-- Set up Green Punch.

defs = {
    alpha             = 200            ,
    basename          = "green_punch"  ,
    light             = -1             ,
    post_effect_color = { a=180, r=30, g=150, b=30 } ,
}

default.register_water (defs)

-- ===================================================================
-- Set up Orange Punch.

defs = {
    alpha             = 200            ,
    basename          = "orange_punch" ,
    light             = -1             ,
    post_effect_color = { a=120, r=190, g=140, b=90 } ,
}

default.register_water (defs)

-- ===================================================================
-- Set up Purple Punch.

defs = {
    alpha             = 200            ,
    basename          = "purple_punch" ,
    light             = -1             ,
    post_effect_color = { a=120, r=168, g=67, b=192 } ,
}

default.register_water (defs)

-- ===================================================================
-- Set up Red Punch.

defs = {
    alpha             = 200            ,
    basename          = "red_punch"    ,
    light             = -1             ,
    post_effect_color = { a=180, r=150, g=30, b=30 } ,
}

default.register_water (defs)

-- ===================================================================
-- Set up Yellow Punch.

defs = {
    alpha             = 200            ,
    basename          = "yellow_punch" ,
    light             = -1             ,
    post_effect_color = { a=120, r=100, g=100, b=10 } ,
}

default.register_water (defs)

-- ===================================================================
-- End of module.