func NewSpriteDrawer(window *glfw.Window, layers int) *SpriteDrawer {
s := new(SpriteDrawer)
vao := gl.GenVertexArray()
vao.Bind()
s.Camera = vec2.Identity
s.Program = CreateProgram("shaders/2d.vert", "shaders/2d.geom", "shaders/texture.frag")
s.Use()
s.camera_uniform = s.GetUniformLocation("camera")
s.Texture = gl.GenTexture()
s.Texture.Bind(gl.TEXTURE_2D_ARRAY)
gl.TexImage3D(gl.TEXTURE_2D_ARRAY, 0, gl.RGBA, 2048, 2048, layers, 0, gl.RGBA, gl.UNSIGNED_BYTE, nil)
gl.TexParameteri(gl.TEXTURE_2D_ARRAY, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D_ARRAY, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
s.Window = window
w, h := window.GetSize()
s.OnScreenResize(w, h)
s.Window.SetSizeCallback(func(window *glfw.Window, w, h int) {
s.OnScreenResize(w, h)
})
return s
}
// onResize sets up a simple 2d ortho context based on the window size
func onResize(window *glfw.Window, w, h int) {
w, h = window.GetSize() // query window to get screen pixels
width, height := window.GetFramebufferSize()
gl.Viewport(0, 0, width, height)
gl.MatrixMode(gl.PROJECTION)
gl.LoadIdentity()
gl.Ortho(0, float64(w), 0, float64(h), -1, 1)
gl.MatrixMode(gl.MODELVIEW)
gl.LoadIdentity()
gl.ClearColor(1, 1, 1, 1)
}
func MouseCoord(window *glfw.Window, xpos, ypos float64) glm.Vec2d {
width, height := window.GetSize()
return glm.Vec2d{xpos / float64(width), 1 - ypos / float64(height)}
}