Rotating Animations

[Zekallinos]

Alright, here's another request that could probably be useful to many other people. What I need is rather self-explanatory, I need to be able to rotate an animation. It doesn't have to be rotating while animating, more like the whole thing is turned to begin with (every frame has the same rotation). And I'm not talking only about the "Angle" propriety of the Animations Cells, since it has to be rotated according to animation center (which will always be middle - 0,0 , not screen or anything) (so basically there's a bit of trigonometry involved). I can't really do this manually, since I'd probably need about 100 angles out of the 360.

I hope this is actually doable, since this "class Sprite_Character < RPG::Sprite" is where the animation are handled (I think?). If it is great, then I owe you in advance ^^. Also, IF possible, I'd like to be able to stop the animation before a certain frame is reached, but that is if it's not too much trouble (like Animation.call(name, frame, angle) or something).

 

[Brewmeister]

Alright, I'm making some progress, but this is still not quite right.
Unfortunately, I have to go rent a car & drive to Ohio. [sarcasm]WooHoo!!![/sarcasm]

See if you can make some progress with it, and I'll take another look when I get home on Friday

module RPG
  class Sprite 
    def animation(animation, hit)
      dispose_animation
      @_animation = animation
      return if @_animation == nil
      # set the rotation based on the global variable
      if $anim_rot != nil && $anim_rot != 0
        #for each frame
        for i in 0..@_animation.frame_max - 1
          # for each cell in each frame
          for j in 0..@_animation.frames[i].cell_max - 1
            angle_orig = @_animation.frames[i].cell_data[j,4]
            @_animation.frames[i].cell_data[j,4] = (angle_orig + $anim_rot) % 360
            x_orig = @_animation.frames[i].cell_data[j,1]
            y_orig = @_animation.frames[i].cell_data[j,2]
            r = Math.hypot(x_orig, y_orig)
            # check x_orig so we don't divide by 0
            if x_orig == 0
              sa_rad = 0
              if y_orig > 0
                sa_rad = 90 * (Math::PI / 180)
              end
              if y_orig < 0
                sa_rad = -90 * (Math::PI / 180)
              end
            else
              sa_rad = Math.atan(y_orig / x_orig)
            end
            rot_rad = $anim_rot * (Math::PI / 180)
            ea_rad = sa_rad + rot_rad
            x_new = r * Math.cos(ea_rad)
            y_new = r * Math.sin(ea_rad)
            @_animation.frames[i].cell_data[j,1] = x_new
            @_animation.frames[i].cell_data[j,2] = y_new
          end
        end
      end
      @_animation_hit = hit
      @_animation_duration = @_animation.frame_max
      animation_name = @_animation.animation_name
      animation_hue = @_animation.animation_hue
      bitmap = RPG::Cache.animation(animation_name, animation_hue)
      if @@_reference_count.include?(bitmap)
        @@_reference_count[bitmap] += 1
      else
        @@_reference_count[bitmap] = 1
      end
      @_animation_sprites = []
      if @_animation.position != 3 or not @@_animations.include?(animation)
        for i in 0..15
          sprite = ::Sprite.new(self.viewport)
          sprite.bitmap = bitmap
          sprite.visible = false
          @_animation_sprites.push(sprite)
        end
        unless @@_animations.include?(animation)
          @@_animations.push(animation)
        end
      end
      update_animation
    end
  end
end

Be Well

 

[Zekallinos]

Thank you, it's a very nice start! I'll just wait a little...

Every time I call that animation, the angles add up. Meaning first time it may be +43, the next time will be +86. I think the problem may be that when you set coordinates (X,Y, and angle) to the cells, it actually stays that number. Probably they should be reset to database original numbers (although I'm not quite familiar with modules at all, so...). Then, why use Math.atan? Doesn't tan works by itself, the result (being in radians) being added to the $anim_rot (in radian too)?

(I'm just speculating, don't really know. It doesn't really rotate in the right way when I continuously rotate it +10 (so after 36 button-smash I make a full twist))

 

[Zekallinos]

Oh, and this :

x_new = r * Math.cos(ea_rad)
y_new = r * Math.sin(ea_rad)

Should be

x_new = x_orig + r * Math.cos(ea_rad)
y_new = y_orig + r * Math.sin(ea_rad)

maybe? Still doesn't rotate right, but it could have something to do...