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Created June 2, 2013 08:56
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function setup()
img=readImage("Platformer Art:Block Brick")
--note that when parameter values change, CreateMesh will be called
--and this will rebuild the mesh at the new size
print("Slide the sliders to change the size of the mesh")
function CreateMesh()
--CreateMesh will be called for the first time when the parameters are defined above, which creates
--a problem with the first one, because MeshHeight hasn't been defined yet (it's the second one!). So
--the first line below just returns if we're not ready to build it yet. So the MeshHeight parameter
--will also call CreateMesh, and this time it will be ok to continue. After this, this function will
--only be called if the user changes size.
if MeshHeight==nil then return end
--clear any existing mesh
if m~=nil then m:clear() else m=mesh() end
--calculate how many images will fit into our mesh
--create the mesh, one big rectangle with 6 vertices
v[1]=vec3(0,0,0) t[1]=vec2(0,0)
v[2]=vec3(MeshWidth,0,0) t[2]=vec2(nx,0)
v[3]=vec3(MeshWidth,MeshHeight,0) t[3]=vec2(nx,ny)
v[4]=vec3(MeshWidth,MeshHeight,0) t[4]=vec2(nx,ny)
v[5]=vec3(0,MeshHeight,0) t[5]=vec2(0,ny)
v[6]=vec3(0,0,0) t[6]=vec2(0,0)
m.shader = shader(TilerShader.vertexShader, TilerShader.fragmentShader)
function draw()
TilerShader = {
vertexShader = [[
// A basic vertex shader
//This is the current model * view * projection matrix
// Codea sets it automatically
uniform mat4 modelViewProjection;
//This is the current mesh vertex position, color and tex coord
// Set automatically
attribute vec4 position;
attribute vec4 color;
attribute vec2 texCoord;
//This is an output variable that will be passed to the fragment shader
varying lowp vec4 vColor;
varying highp vec2 vTexCoord;
void main()
//Pass the mesh color to the fragment shader
vColor = color;
vTexCoord = texCoord;
//Multiply the vertex position by our combined transform
gl_Position = modelViewProjection * position;
fragmentShader = [[
// A basic fragment shader
//Default precision qualifier
precision highp float;
//This represents the current texture on the mesh
uniform lowp sampler2D texture;
//The interpolated vertex color for this fragment
varying lowp vec4 vColor;
//The interpolated texture coordinate for this fragment
varying highp vec2 vTexCoord;
void main()
//Sample the texture at the interpolated coordinate
lowp vec4 col = texture2D( texture, vec2(mod(vTexCoord.x,1.0), mod(vTexCoord.y,1.0))) * vColor;
//Set the output color to the texture color
gl_FragColor = col;
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