Gists Codea Upload

Project.lua

--# Main
-- blendmode bench
displayMode(STANDARD)
function setup()
    -- default colors
    DST_background = color(0,0)
    DST_foreground = color(255, 0, 0, 255)
    SRC_background = color(0,0)
    SRC_foreground = color(35, 0, 255, 255)
    -- buttons
    controlPanel()
    
    createImages()
    updateImages()
    
    text0 = "DST: image already there"
    text1 = "SRC: image to be blended onto DST"
    text2 = "Blended result:"
    text3 = "SRC sprited on top of DST"
end
function controlPanel()
    parameter.clear()
    ready = false
    paramBlendMode()
    paramImages()
    ready = true
end

-- ###############  Blendmode selection  ################

-- this is the interface to choose one of the various syntext of blendmode()
function paramBlendMode()
    parameter.integer("blendmode_syntax",1,3,blendmode_syntax or 1,function()
        switchBlendMode(blendmode_syntax)
        if ready then controlPanel() end
    end)

end
function switchBlendMode(i)
    if i == 1 then selectBlendMode1() end
    if i == 2 then selectBlendMode2() end
    if i == 3 then selectBlendMode3() end
end
function selectBlendMode1()
    title = "1 parameter blendMode:"
    doc = "preset simple modes"
    choices1 = {"NORMAL","ADDITIVE","MULTIPLY",
        ["NORMAL"]=NORMAL, ["ADDITIVE"]=ADDITIVE, ["MULTIPLY"]=MULTIPLY}
    blendParams = {1}
    parameter.integer("param1_1",1,3,param1_1 or 1,function() 
        textP1=choices1[param1_1] 
        p1 = choices1[textP1] 
        textBlend = "blendMode( " .. textP1 .. " )"
        printOut()
    end)
    setBlendMode = function() blendMode(p1) end
end
function printOut()
    output.clear()
    print(textBlend)
end
choices21 = {
    "ZERO","ONE",
    "DST_COLOR","ONE_MINUS_DST_COLOR",
    "SRC_ALPHA","ONE_MINUS_SRC_ALPHA",
    "DST_ALPHA","ONE_MINUS_DST_ALPHA",
    "SRC_ALPHA_SATURATE",
    ["ZERO"]=ZERO, ["ONE"]=ONE,
    ["DST_COLOR"]=DST_COLOR, ["ONE_MINUS_DST_COLOR"]=ONE_MINUS_DST_COLOR,
    ["SRC_ALPHA"]=SRC_ALPHA, ["ONE_MINUS_SRC_ALPHA"]=ONE_MINUS_SRC_ALPHA,
    ["DST_ALPHA"]=DST_ALPHA, ["ONE_MINUS_DST_ALPHA"]=ONE_MINUS_DST_ALPHA,
    ["SRC_ALPHA_SATURATE"]=SRC_ALPHA_SATURATE,
    }
choices22 = {
    "ZERO","ONE",
    "SRC_COLOR","ONE_MINUS_SRC_COLOR",
    "SRC_ALPHA","ONE_MINUS_SRC_ALPHA",
    "DST_ALPHA","ONE_MINUS_DST_ALPHA",
    ["ZERO"]=ZERO, ["ONE"]=ONE,
    ["SRC_COLOR"]=SRC_COLOR, ["ONE_MINUS_SRC_COLOR"]=ONE_MINUS_SRC_COLOR,
    ["SRC_ALPHA"]=SRC_ALPHA, ["ONE_MINUS_SRC_ALPHA"]=ONE_MINUS_SRC_ALPHA,
    ["DST_ALPHA"]=DST_ALPHA, ["ONE_MINUS_DST_ALPHA"]=ONE_MINUS_DST_ALPHA,
    }
doc2 = {
    ["ZERO"] = "(0,0,0,0)",
    ["ONE"] = "(1,1,1,1)",
    ["DST_COLOR"] = "( D.r, D.g, D.b, D.a )/255",
    ["ONE_MINUS_DST_COLOR"] = "(1,1,1,1) - ( D.r, D.g, D.b, D.a )/255",
    ["SRC_COLOR"] = "( S.r, S.g, S.b, S.a )/255",
    ["ONE_MINUS_SRC_COLOR"] = "(1,1,1,1) - ( S.r, S.g, S.b, S.a )/255",
    ["SRC_ALPHA"] = "( S.a, S.a, S.a, S.a )/255",
    ["ONE_MINUS_SRC_ALPHA"] = "(1,1,1,1) - ( S.a, S.a, S.a, S.a )/255",
    ["DST_ALPHA"] = "( D.a, D.a, D.a, D.a )/255",
    ["ONE_MINUS_DST_ALPHA"] = "(1,1,1,1) - ( D.a, D.a, D.a, D.a )/255",
    ["SRC_ALPHA_SATURATE"] = "(f,f,f,1) with f = min ( S.a, 255 - D.a )/255"
    }
doc3 = {
    ["ZERO"] = "0",
    ["ONE"] = "1",
    ["DST_COLOR"] = "D.a /255",
    ["ONE_MINUS_DST_COLOR"] = "1 -  D.a /255",
    ["SRC_COLOR"] = "S.a /255",
    ["ONE_MINUS_SRC_COLOR"] = "1 - S.a /255",
    ["SRC_ALPHA"] = "S.a /255",
    ["ONE_MINUS_SRC_ALPHA"] = "1 - S.a /255",
    ["DST_ALPHA"] = "D.a /255",
    ["ONE_MINUS_DST_ALPHA"] = "1 -  D.a /255",
    ["SRC_ALPHA_SATURATE"] = "min ( S.a, 255 - D.a )/255"
    }
function selectBlendMode2()
    title = "2 parameter blendMode:" 
    parameter.integer("param2_1",1,#choices21, param2_1 or 1,function() 
        updateBlendMode2()
    end)
    parameter.integer("param2_2",1,#choices22, param2_2 or 1,function() 
        updateBlendMode2()
    end)
    setBlendMode = function() blendMode(p1,p2) end
end
function updateBlendMode2()
    textP1=choices21[param2_1] 
    textP2=choices22[param2_2] 
    p1 = choices21[textP1]
    p2 = choices22[textP2]
    textBlend = "blendMode(\n  " .. (textP1 or "") .. ",\n  " .. (textP2 or "") .. "\n)"
    printOut()
    doc = "for r,g,b,a with S=SRC and D=DST:\n"
        .. "new_color = S * s + D * d" .."\n"
        .. "s = " .. (doc2[textP1] or "").."\n"
        .. "d = " .. (doc2[textP2] or "")
end

function selectBlendMode3()
    title = "4 parameter blendMode:" 
    parameter.integer("param2_1",1,#choices21, param2_1 or 1,function() 
        updateBlendMode3()
    end)
    parameter.integer("param2_2",1,#choices22, param2_2 or 1,function() 
        updateBlendMode3()
    end)
    parameter.integer("param2_3",1,#choices21, param2_3 or 1,function() 
        updateBlendMode3()
    end)
    parameter.integer("param2_4",1,#choices22, param2_4 or 1,function() 
        updateBlendMode3()
    end)
    setBlendMode = function() blendMode(p1,p2,p3,p4) end
end

function updateBlendMode3()
    textP1=choices21[param2_1] 
    textP2=choices22[param2_2] 
    textP3=choices21[param2_3] 
    textP4=choices22[param2_4] 
    p1 = choices21[textP1]
    p2 = choices22[textP2]
    p3 = choices21[textP3]
    p4 = choices22[textP4]
    textBlend = "blendMode(\n  " .. (textP1 or "") .. ",\n  " .. (textP2 or "")
        .. ",\n  " .. (textP3 or "") .. ",\n  " .. (textP4 or "") .. "\n)"
    printOut()
    doc = "for r,g,b with S=SRC and D=DST:\n"
        .. "new_color = S * s + D * d" .."\n"
        .. "s = " .. (doc2[textP1] or "").."\n"
        .. "d = " .. (doc2[textP2] or "").."\n"
        .. "new_a = S.a * s + D.a * d \n"
        .. "s = " .. (doc3[textP3] or "").."\n"
        .. "d = " .. (doc3[textP4] or "").."\n"
    
end

-- ###############  test images selection  ################

function paramImages()
    parameter.integer("DST_image", 1, 3, DST_image, updateImages)
    parameter.integer("SRC_image", 1, 3, SRC_image, updateImages)
    parameter.color("DST_background",DST_background,updateImages)
    parameter.color("DST_foreground",DST_foreground,updateImages)
    parameter.color("SRC_background",SRC_background,updateImages)
    parameter.color("SRC_foreground",SRC_foreground,updateImages)
end

function createImages()
    DST_image = 1
    SRC_image = 1
    -- real images
    img0 = square()
    img1 = square()
    img2 = square()
end
    
function updateImages()
    if not ready then return end

    if DST_image == 1 then
        simplePattern(img0, DST_background, DST_foreground, 0)
    elseif  DST_image == 2 then
        colorPattern(img0,0)
    elseif  DST_image == 3 then
        textPattern(img0,DST_background, DST_foreground, 90)
    end

    if SRC_image == 1 then
        simplePattern(img1, SRC_background, SRC_foreground, 90)
    elseif  SRC_image == 2 then
        colorPattern(img1,90)
    elseif  SRC_image == 3 then
        textPattern(img1,SRC_background, SRC_foreground, 0)
    end
end

-- empty image of final size
function square()
    local m = math.min(WIDTH,HEIGHT)
    local w = m/5
    local h = w
    local img = image(w*2,h*2)
    setContext(img)
        background(0,0)
    setContext()
    return img
end

-- this is a diagonal grid to visualize transparency
function grid()
    local w = 20
    local img = image(w,w)
    setContext(img)
        noSmooth()
        background(0)
        strokeWidth(0.5)
        stroke(128)
        for i=1,w/2 do
            line(0,i*2,i*2,0)
            line(i*2, w, w, i*2)
        end
    setContext()
    return img
end
-- a background image
back = grid()

-- this is a text pattern
function textPattern(imgOut,c0,c1,angle)
    local w,h = imgOut.width, imgOut.height
    resetMatrix()
    pushStyle()
    textMode(CENTER)
    font("Futura-CondensedExtraBold")
    fontSize(40)
    setContext(imgOut)
        background(c0)
        fill(c1)
        translate(w/2, h/2)
        rotate(angle or 0)
        text("HELLO WORLD" ,0,0)
    setContext()
    resetMatrix()
    popStyle()
    return imgOut
end

-- this is a simple pattern
function simplePattern(imgOut,c0,c1,angle)
    local w,h = imgOut.width, imgOut.height
    resetMatrix()
    ellipseMode(CENTER)
    setContext(imgOut)
        background(c0)
        fill(c1)
        translate(w/2, h/2)
        rotate(angle or 0)
        ellipse(0,0,w/2,h/4)
    setContext()
    resetMatrix()
    return imgOut
end

-- this is a color pattern
function smallColorPattern()
    -- first make a low resolution color pattern
    local w = 10
    local img = image(w,25)
    local as = { 0, 0.25, 0.5, 0.75, 1 }
    local cs = { color(255), color(255,0,0), color(0,255,0), color(0,0,255)}
    local y = 1
    setContext(img)
        noSmooth()
        background(0,0,0,0)
        for _,a in pairs(as) do
            strokeWidth(1)
            local cl = color( 255,255,255,255*a)
            stroke(cl)
            line(0,y,w,y)
            y = y + 1
        end
        for _,c in pairs(cs) do for _,a in pairs(as) do
            strokeWidth(1)
            local cl = color( c.r*a, c.g*a, c.b*a, c.a )
            stroke(cl)
            line(0,y,w,y)
            y = y + 1
        end end
    setContext()
    return img
end
local colorGrid = smallColorPattern()
function colorPattern(imgOut,angle)
    -- then sprite it into output image
    local w,h = imgOut.width, imgOut.height
    resetMatrix()
    spriteMode(CENTER)
    setContext(imgOut)
        background(0,0)
        translate(w/2, h/2)
        rotate(angle or 0)
        sprite(colorGrid, 0,0,w,h )
    setContext()
    resetMatrix()
    return imgOut
end

-- ###############  blending  ################

function updateBlending()
    local w,h = img2.width, img2.height
    pushStyle()
    spriteMode(CORNER)
    setContext(img2)
        blendMode(NORMAL)
        background(0,0,0,0)
        sprite(img0,0,0,w,h)
        setBlendMode()
        sprite(img1,0,0,w,h)
    setContext()
    blendMode(NORMAL)
    popStyle()
end

function draw()
    -- This sets a dark background color 
    background(40, 40, 50)

    local m = math.min(WIDTH,HEIGHT)
    local w = m/5
    local h = w
    local s = (m-w*4)/3
    local x,y
    
    fill(255)
    fontSize(17)
    spriteMode(CENTER)
    
    -- DST: image already there
    x,y = w+s,h*3+s*2
    text(text0, x, y+h+s/2)
    sprite(back,x,y,img0.width,img0.height)
    sprite(img0,x,y)

    -- SRC: image to be blended onto DST
    x,y = w+s,h+s
    text(text1,x,y+h+s/2)
    sprite(back,x,y,img0.width,img0.height)
    sprite(img1,x,y)

    -- Blended result:
    updateBlending()
    x,y = w*3+s*2,h+s
    text(text2 ,x,y+h+s/2)
    text(text3 ,x,y+h+s)
    sprite(back,x,y,img0.width,img0.height)
    sprite(img2,x,y)

    -- details of the blending process
    local t = title .."\n\n" .. textBlend
    local tw,th =textSize(t)
    x,y = w*3+s*2, HEIGHT - th/2 -20
    text( t ,x,y)
    
    y = (y + h*2 +s)/2
    text(doc ,x,y)

end