Very good
Sorry I’m late, but I was doing various tests on the effects. The comments were very helpful.
I rewrote a piece of code out of context so I can show you. Then I think he goes. Only thing I do not understand is in touch method that give value “t” because executes a perfect turning. Also how I decide which way I want to go the edge (photo)?
I think I will have solved this all perfect. I thank you again
code:
--snap to use as a card or tile (Slightly larger to have the desidered border) local card = display.newSnapshot( 230, 230 ) card.x = display.contentCenterX card.y = display.contentCenterY --snap group local cardG = card.group --background (used as a card board) local bg = display.newRect( cardG, 0, 0, 200, 200 ) bg:setFillColor( 1, 1, 1, 0 ) bg.strokeWidth = 20 bg:setStrokeColor(.7, .7, .7, 1) --hearts suit local hearts = display.newImageRect( cardG, "hearts.png", 60, 60 ) hearts.x = bg.x - (bg.width\*0.5) + (hearts.width\*0.5) + bg.strokeWidth --diamonds suit local diamonds = display.newImageRect( cardG, "diamonds.png", 60, 60 ) diamonds.x = bg.x + (bg.width\*0.5) - (diamonds.width\*0.5) - bg.strokeWidth --clubs suit local clubs = display.newImageRect( cardG, "clubs.png", 60, 60 ) clubs.y = bg.y - (bg.height\*0.5) + (clubs.height\*0.5) + bg.strokeWidth --spades suit local spades = display.newImageRect( cardG, "spades.png", 60, 60 ) spades.y = bg.y + (bg.height\*0.5) - (spades.height\*0.5) - bg.strokeWidth --centre of card local centre = display.newRect( cardG, 0, 0, 60, 60 ) --button that serves the user to turn the card local rotateButton = display.newRect( 0, 0, 30, 50 ) rotateButton:setFillColor( 0, 1, 0 ) rotateButton.x = rotateButton.width rotateButton.y = display.contentCenterY --rotateButton touch event function rotateButton:touch( event ) if ( event.phase == "began" ) then display.getCurrentStage():setFocus(self, event.id) self.isFocus = true elseif(self.isFocus) then if event.phase == "moved" then --distance path with his finger by the user local distanceTraveled = (event.x-event.xStart) --distance in proportion to the width of the paper local distanceInProportion = (distanceTraveled/card.width)\*2 print(distanceInProportion) if(distanceInProportion \> 0) and (distanceInProportion \< 2) then --tilting the paper by changing the scale (old method) --card.xScale = 1-distanceInProportion --tilting the paper with the new effect --I multiplied by seven only to see the operation but do not understand how to calculate the right number card.fill.effect.t = distanceInProportion\*7 end elseif event.phase == "ended" or event.phase == "cancelled" then display.getCurrentStage():setFocus( self, nil ) self.isFocus = false end end return true end rotateButton:addEventListener( "touch" ) local kernel = { category = "filter", name = "rotate" } kernel.vertexData = { { index = 0, name = "t", default = 0 } } kernel.fragment = [[const P\_UV float PI = 3.14159; const P\_UV float WIDTH = 13.; #define NPIXELS CoronaTexelSize.z \* WIDTH P\_UV float LessThan (P\_UV float threshold, P\_UV float x) { return step(abs(x), threshold); // 1.0 if true, 0.0 otherwise } P\_UV float MoreThan (P\_UV float threshold, P\_UV float x) { return step(-abs(x), threshold); // 1.0 if true, 0.0 otherwise (the negative just accounts for exactly equal values) } P\_UV float ProjectX (P\_UV float x, P\_UV float denom) { return .5 + (x - .5) / denom; } P\_UV float InBounds (P\_UV vec2 uv) { P\_UV vec2 from\_center = step(vec2(-.5), abs(uv - .5)); // 1.0 if inside [0, 1] along axis, 0.0 otherwise (done for x and y) return min(from\_center.x, from\_center.y); // If either is 0.0, we're out-of-bounds; otherwise we're inside } P\_COLOR vec4 FragmentKernel( P\_UV vec2 texCoord ) { P\_UV float angle = CoronaVertexUserData.x \* .09 \* PI; P\_UV float cosa = cos(angle), sina = sin(angle), xcur = texCoord.x; P\_UV float denom = sign(cosa) \* max(abs(cosa), 1e-4); // avoid divides by 0 to avoid driver issues, etc. P\_UV float off\_edge = InBounds(texCoord); texCoord.x = ProjectX(texCoord.x, denom); P\_COLOR vec4 pixel = texture2D(CoronaSampler0, texCoord) \* off\_edge; P\_UV float neighbor\_x = ProjectX(xcur - NPIXELS \* sina, denom); // look a few pixels to the left or right (depending on angle and distance from sideways) P\_UV float at\_center\_and\_sideways = MoreThan(.9975, sina) \* LessThan(NPIXELS / 2., xcur - .5); // the multiply is basically an "and" // if both predicates return 1.0, it's 1.0 // otherwise it's 0.0 texCoord.x = mix(neighbor\_x, .5, at\_center\_and\_sideways); // "interpolate" (using our 0.0 or 1.0 result) to pick a value P\_COLOR vec4 neighbor = texture2D(CoronaSampler0, texCoord) \* InBounds(texCoord); return CoronaColorScale(mix(mix(vec4(0.), vec4(1., 0., 0., 1.), neighbor.a), pixel, pixel.a)); } ]] graphics.defineEffect(kernel) --Apply the new effect card.fill.effect = "filter.custom.rotate"
