Source Code for Module toon.effects.simplechroma

  1  #!/usr/bin/env python 
  2  """ 
  3  GLSL shaders with SDL, OpenGL texture and Python 
  4  """ 
  5  from pygame.locals import * 
  6  from OpenGL.GL import * 
  7  from OpenGL.error import GLError 
  8  from OpenGL.GLU import * 
  9  from rats.glsl import ShaderProgram 
 10  from rats.glsl import ShaderError 
 11  from toon import fx 
 12  from toon import optgroup 
 13   
 14  # Vertex shader that does nothing 
 15  # 
 16  # :texcoord0: variable passed to the fragment shader 
 17  # :texdim0: variable passed to the fragment shader 
 18  vert = """ 
 19  varying vec2 texcoord0; 
 20  varying vec2 texdim0; 
 21  void main() 
 22  { 
 23      gl_Position = ftransform(); 
 24      texcoord0 = vec2(gl_TextureMatrix[0] * gl_MultiTexCoord0); 
 25      texdim0 = vec2(abs(gl_TextureMatrix[0][0][0]), abs(gl_TextureMatrix[0][1][1])); 
 26  } 
 27  """ 
 28   
 29  # Simple fragment shader for boolean chroma-keying.  
 30  #  
 31  # Makes pixels of a texture transparent if proximity to keying_color is under threshold. 
 32  # Make sure to use rectangle textures.  
 33  # :param keying_color: The RGB keying color that will be made transparent. 
 34  # :param thresh: The distance from the color for a pixel to disappear. 
 35  # :author: Alexandre Quessy <alexandre@quessy.net> 2009 
 36  # :license: GNU Public License version 3 
 37  frag = """ 
 38  #extension GL_ARB_texture_rectangle : enable 
 39  // user configurable variables (read-only here) 
 40  uniform vec3 keying_color; 
 41  uniform vec3 thresh; 
 42  uniform float alpha_under_thresh; 
 43  // the texture 
 44  uniform sampler2DRect image; 
 45  // data passed from vertex shader: 
 46  varying vec2 texcoord0; 
 47  varying vec2 texdim0; 
 48   
 49  void main(void) 
 50  { 
 51      vec3 input_color = texture2DRect(image, texcoord0).rgb; 
 52      float input_alpha = gl_Color.a; 
 53      float output_alpha = input_alpha; 
 54      vec3 delta = abs(input_color - keying_color); 
 55      if (delta.r <= thresh.r && delta.g <= thresh.g && delta.b <= thresh.b) 
 56      { 
 57          output_alpha = alpha_under_thresh; 
 58      } 
 59      gl_FragColor = vec4(input_color, output_alpha);  
 60  } 
 61  """ 
 62  # ----------------------------  functions ---------------------------- 
 63 -class SimpleChromaOptions(optgroup.OptionsGroup): 
 64 -    def __init__(self): 
 65          self.color = [0.2, 0.8, 0.0] 
 66          self.thresh = [0.8, 0.8, 0.8] 
 67          self.texture_id = 0 
 68          self.alpha_under_thresh = 0.1 
 69   
 70 -class SimpleChromaEffect(fx.Effect): 
 71 -    def __init__(self): 
 72          fx.Effect.__init__(self) 
 73          self.program = None 
 74          self.options = SimpleChromaOptions() 
 75          self.name = "simplechroma" 
 76          #print("init %s" % (self.name)) 
 77           
 78 -    def setup(self): 
 79          global vert 
 80          global frag 
 81          if True: 
 82          #try: 
 83              self.program = ShaderProgram() 
 84              self.program.add_shader_text(GL_VERTEX_SHADER_ARB, vert) 
 85              self.program.add_shader_text(GL_FRAGMENT_SHADER_ARB, frag) 
 86              self.program.linkShaders() 
 87          #except Exception, e:  
 88          #    print(e.message) 
 89          #else: 
 90              self.loaded = True 
 91              #print(self.config) 
 92       
 93 -    def pre_draw(self): 
 94          if self.enabled and self.loaded: 
 95              try: 
 96                  self.program.enable() 
 97              except Exception, e:  
 98                  print(e.message) 
 99              self.program.glUniform1i("image", self.options.texture_id) 
100              self.program.glUniform3f( 
101                  "keying_color", *self.options.color) 
102              self.program.glUniform3f( 
103                  "thresh", *self.options.thresh) 
104              self.program.glUniform1f("alpha_under_thresh", self.options.alpha_under_thresh) 
105  #self.config['alpha_under_thresh']) 
106   
107 -    def post_draw(self): 
108          if self.enabled and self.loaded: 
109              try: 
110                  self.program.disable() 
111              except Exception, e:  
112                  print e.message 
113   
114 -def create_effect(): 
115      return SimpleChromaEffect() 
116