LÖVE

Code: Select all

local shader = love.graphics.newShader("palette/shader.glsl")
local palette = love.graphics.newImage("palette/Palette.png")
local sprite = love.graphics.newImage("sprite.png")
sprite:setFilter("nearest", "nearest")

function love.load()
   row = 0.0
end


local w, h = love.graphics.getDimensions()
function love.draw()
   love.graphics.setColor(0,0,0,1)
   love.graphics.rectangle('fill',0,0,w,h)
   love.graphics.setColor(1,1,1,1)
   love.graphics.setShader(shader)
   shader:send("palette", palette)
   shader:send("row", row)
   love.graphics.draw(sprite, 20, 20, 0, 8, 8)
   love.graphics.setShader()
   love.graphics.setColor(1,1,1,1)
   love.graphics.print(" row :"..row, 0, 0)
end

function love.update(dt)
   if love.keyboard.isDown("=") then
      row = row + 0.005
   elseif love.keyboard.isDown("-") then
      row = row - 0.005
   end
end

-- function love.keypressed(key)
--   if key == '=' then
--     row = row + 0.01
--   elseif key == '-' then
--     row = row - 0.01
--   end
-- end

Code: Select all

uniform sampler2D palette;
extern float row;

vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 screen_coords) {
   vec2 u = Texel(texture, texture_coords).ra;
   vec4 pixel = Texel(palette, vec2(u.r, row));
   pixel.a = u.g;
   return pixel * color;
}