video_mapping

Author: monkstone

processing_app/library/glvideo/data/checkerboard.png

@@ -29,9 +29,8 @@ def report_config
   devices = GLCapture.list
   puts('Devices:')
   devices.each { |dev| puts dev }
-  if (0 < devices.length)
-    configs = GLCapture.configs(devices[0]).to_a # ruby array
-    puts('Configs:')
-    configs.map { |cam| puts cam.strip }
-  end
+  return unless 0 < devices.length
+  configs = GLCapture.configs(devices[0]).to_a # ruby array
+  puts('Configs:')
+  configs.map { |cam| puts cam.strip }
 end

processing_app/library/glvideo/data/launch2.mp4

@@ -0,0 +1,104 @@
+load_library :glvideo
+include_package 'gohai.glvideo'
+
+# placeholder for vector coordinates
+Vect = Struct.new(:x, :y)
+# placeholder for image sources
+ImageSource = Struct.new(:video, :image)
+
+attr_reader :sources, :sel, :video, :corners, :quads, :last_mouse_move, :sel_corner
+RES = 5	# number of subdivisions (e.g. 5 x 5)
+
+def setup
+  @last_mouse_move = 0
+  @sel_corner = -1
+  no_cursor
+  @video = GLMovie.new(self, data_path('launch2.mp4'))
+  video.loop
+  image = load_image(data_path('checkerboard.png'))
+  @sources = ImageSource.new(video, image)
+  @sel = sources.video
+  @corners = [
+    Vect.new(width / 2 - 100, height / 2 - 100),
+    Vect.new(width / 2 + 100, height / 2 - 100),
+    Vect.new(width / 2 + 100, height / 2 + 100),
+    Vect.new(width / 2 - 100, height / 2 + 100)
+  ]
+  @quads = create_mesh(sel, corners, RES)
+end
+
+def draw
+  background(0)
+  video.read if (sel.respond_to?(:read) && video.available)
+  # regenerate mesh if we're dragging a corner
+  if (sel_corner != -1 && (pmouse_x != mouse_x || pmouse_y != mouse_y))
+    corners[sel_corner] = Vect.new(mouse_x, mouse_y)
+    # this improves performance, but will be replaced by a
+    # more elegant way in a future release
+    @quads = []
+    Java::JavaLang::System.gc # this is  generally not recommended
+    @quads = create_mesh(sel, corners, RES)
+  end
+
+  # display
+  quads.map { |quad| shape(quad) } if !quads.empty?
+  # hide the mouse cursor after two seconds
+  if (pmouse_x != mouse_x || pmouse_y != mouse_y)
+    cursor
+    @last_mouse_move = millis
+  elsif (!last_mouse_move.zero? && 2000 < millis - last_mouse_move)
+    no_cursor
+    @last_mouse_move = 0
+  end
+end
+
+def mouse_pressed
+  corners.each_with_index do |corner, i|
+    return @sel_corner = i if dist(mouse_x, mouse_y, corner.x, corner.y) < 20
+  end
+  # no corner? then switch texture
+  @sel = sel.respond_to?(:loop) ? sources.image : sources.video
+  quads = create_mesh(sel, corners, RES)
+end
+
+def mouse_released
+  @sel_corner = -1
+end
+
+def create_mesh(tex, corners, res)
+  transform = PerspectiveTransform.get_quad_to_quad(
+    0, 0, tex.width, 0,                   # top left, top right
+    tex.width, tex.height, 0, tex.height, # bottom right, bottom left
+    corners[0].x, corners[0].y, corners[1].x, corners[1].y,
+    corners[2].x, corners[2].y, corners[3].x, corners[3].y
+  )
+  warp_perspective = WarpPerspective.new(transform)
+  x_step = tex.width.to_f / res
+  y_step = tex.height.to_f / res
+  quads = []
+  (0...res).each do |y|
+    (0...res).each do |x|
+      texture_mode(NORMAL)
+      sh = create_shape
+      sh.begin_shape(QUAD)
+      sh.no_stroke
+      sh.texture(tex)
+      sh.normal(0, 0, 1)
+      point = warp_perspective.map_dest_point(x * x_step, y * y_step)
+      sh.vertex(point.get_x.to_f, point.get_y.to_f, 0, x.to_f / res, y.to_f / res)
+      point = warp_perspective.map_dest_point((x+1) * x_step, y * y_step)
+      sh.vertex(point.get_x.to_f, point.get_y.to_f, 0, (x + 1).to_f / res, y.to_f / res)
+      point = warp_perspective.map_dest_point((x+1) * x_step, (y + 1) * y_step)
+      sh.vertex(point.get_x.to_f, point.get_y.to_f, 0, (x + 1).to_f / res, (y + 1).to_f / res)
+      point = warp_perspective.map_dest_point(x * x_step, (y + 1) * y_step)
+      sh.vertex(point.get_x.to_f, point.get_y.to_f, 0, x.to_f / res, (y + 1).to_f / res)
+      sh.end_shape
+      quads[y * res + x] = sh
+    end
+  end
+  quads
+end
+
+def settings
+  full_screen(P2D)
+end