3D touch

gistfile1.txt

function setup()
    size=50  --size of circles
    n=30  --number of circle
    counter=0 --for showing text on screen when we have a hit
    CreateImages() --create images
    parameter.integer("FPS",0,60,60) --show running speed on screen
    img=image(WIDTH,HEIGHT) 
end

function draw()
    FPS=FPS*.9+.1/DeltaTime
    if T~=nil then --draw on hidden image if we've had a hit
        
        setContext(img)
    else
        background(80)
    end
    --if we've had a touch, draw to an image instead of the screen, just this one time
    perspective()
    camera(0,0,-200,0,0,-1000,0,1,0)
    --draw all circle meshes
    for i,p in pairs(b) do
        pushMatrix()
        translate(p.x,p.y,p.z)
        --if we've had a touch, set the shader, and id number
        --the shader will put this id number in all the pixels of the circle image
        --(transparent pixels will be discarded)
        if T~=nil then 
            p.m.shader.id=p.id/255
        end
        p.m:draw()
        if T~=nil then p.m.shader.id=0 end
        popMatrix()
    end
    --if we've had a touch, stop drawing on the image, and test for a hit on the image
    if T~=nil then 
        setContext()  
        message=testHit() --message showing what we hit
        counter=120
        d=vec2(T.x,T.y)
        T=nil
    end
    --all the code below does is to draw the message on the screen if we had a touch
    if counter>0 then  --show for as long as counter>0, currently 2 seconds
        ortho()  --this and next statement required to allow us to draw text on a 3D screen
        viewMatrix(matrix()) 
        pushStyle()
        fill(255)
        ellipse(d.x,d.y,20)
        textMode(CORNER)
        fontSize(36)
        text(message,50,HEIGHT-50) --message
        popStyle()
        counter=counter-1 --decrement counter
    end
end

function touched(touch)
    --if we have a touch, store the x,y details
    if touch.state==ENDED then 
        T=vec2(touch.x,touch.y)
    end 
end

--test pixel that was touched
--if it was a circle, it will have a colour of r,0,0 where r = id of circle
function testHit()
    local r,g,b=img:get(T.x,T.y)
    if g+b==0 and r>0 then
       return "You touched "..r
    else return "You missed!" 
    end
end


idShader = {
vertexShader = [[
uniform mat4 modelViewProjection;
attribute vec4 position;
attribute vec4 color;
attribute vec2 texCoord;
varying lowp vec4 vColor;
varying highp vec2 vTexCoord;
void main()
{
    vColor = color;
    vTexCoord = texCoord;
    gl_Position = modelViewProjection * position;
}
]],
fragmentShader = [[
precision highp float;
uniform lowp sampler2D texture;
uniform float id;
varying lowp vec4 vColor;
varying highp vec2 vTexCoord;
void main()
{
    lowp vec4 col=texture2D(texture, vTexCoord);
    if (id==0. || col.a<0.2) gl_FragColor=col;
    else gl_FragColor = vec4(id,0.,0.,1.);
}
]]}

function CreateImages()
    b={}  --table of circles
    for i=1,n do  --create circles
        p={}  --table to hold details for each circle
        p.id=i  --id number of circle
        p.m=mesh()  --create mesh for circle, one per circle
        local img=image(size,size)  --create drawing on an image
        setContext(img)
        fill(math.random(0,255),math.random(0,255),math.random(0,255))
        ellipse(size/2,size/2,size)
        fill(0)
        fontSize(24)
        text(i,size/2,size/2)  --draw id number on circle
        setContext()  --done drawing our image
        p.m:addRect(0,0,size,size)  --add circle to mesh
        p.m:setRectTex(1,0,0,1,1)
        p.m.texture=img
        p.m.shader=shader(idShader.vertexShader,idShader.fragmentShader)
        p.m.shader.id=0
        --random position
        p.x,p.y,p.z=math.random(-100,100),math.random(-200,200),-math.random(300,1000)
        table.insert(b,p) --add to table of circles
    end
    --insert an ordinary image that can't be touched
    local img=readImage("Planet Cute:Character Princess Girl")
    p={}
    p.id=0
    p.m=mesh()
    p.m:addRect(0,0,img.width,img.height)  --add circle to mesh
    p.m:setRectTex(1,0,0,1,1)
    p.m.texture=img
    p.m.shader=shader(idShader.vertexShader,idShader.fragmentShader)
    p.m.shader.id=0
    --random position
    p.x,p.y,p.z=math.random(-100,100),math.random(-200,200),-math.random(300,1000)
    table.insert(b,p) --add to table of circles
    
    table.sort(b,function(i,j) return i.z<j.z end) --sort by distance
end