FXStage.js

var glu = require('pex-glu');
var Context = glu.Context;
var ScreenImage = glu.ScreenImage;
var RenderTarget = glu.RenderTarget;
var Program = glu.Program;
var Texture2D = glu.Texture2D;
var FXResourceMgr = require('./FXResourceMgr');

var FXStageCount = 0;

function FXStage(source, resourceMgr, fullscreenQuad) {
  this.id = FXStageCount++;
  this.gl = Context.currentContext;
  this.source = source || null;
  this.resourceMgr = resourceMgr || new FXResourceMgr();
  this.fullscreenQuad = fullscreenQuad || new ScreenImage();
  this.defaultBPP = 8;
}

FXStage.prototype.reset = function() {
  this.resourceMgr.markAllAsNotUsed();
};

FXStage.prototype.getOutputSize = function(width, height, verbose) {
  if (width && height) {
    return {
      width: width,
      height: height
    };
  }
  else if (this.source) {
    return {
      width: this.source.width,
      height: this.source.height
    };
  }
  else {
    var viewport = this.gl.getParameter(this.gl.VIEWPORT);
    return {
      width: viewport[2],
      height: viewport[3]
    };
  }
};

FXStage.prototype.getRenderTarget = function(w, h, depth, bpp) {
  depth = depth || false;
  bpp = bpp || this.defaultBPP;
  var resProps = {
    w: w,
    h: h,
    depth: depth,
    bpp: bpp
  };
  var res = this.resourceMgr.getResource('RenderTarget', resProps);
  if (!res) {
    var renderTarget = new RenderTarget(w, h, resProps);
    res = this.resourceMgr.addResource('RenderTarget', renderTarget, resProps);
  }
  res.used = true;
  return res.obj;
};

FXStage.prototype.getFXStage = function(name) {
  var resProps = {};
  var res = this.resourceMgr.getResource('FXStage', resProps);
  if (!res) {
    var fxState = new FXStage(null, this.resourceMgr, this.fullscreenQuad);
    res = this.resourceMgr.addResource('FXStage', fxState, resProps);
  }
  res.used = true;
  return res.obj;
};

FXStage.prototype.asFXStage = function(source, name) {
  var stage = this.getFXStage(name);
  stage.source = source;
  stage.name = name + '_' + stage.id;
  return stage;
};

FXStage.prototype.getShader = function(code) {
  if (code.indexOf('.glsl') == code.length - 5) {
    throw 'FXStage.getShader - loading files not supported yet.';
  }
  var resProps = { code: code };
  var res = this.resourceMgr.getResource('Program', resProps);
  if (!res) {
    var program = new Program(code);
    res = this.resourceMgr.addResource('Program', program, resProps);
  }
  res.used = true;
  return res.obj;
};

FXStage.prototype.getSourceTexture = function(source) {
  if (source) {
    if (source.source) {
      if (source.source.getColorAttachment) {
        return source.source.getColorAttachment(0);
      }
      else return source.source;
    }
    else if (source.getColorAttachment) {
      return source.getColorAttachment(0);
    }
    else return source;
  }
  else if (this.source) {
    if (this.source.getColorAttachment) {
      return this.source.getColorAttachment(0);
    }
    else return this.source;
  }
  else throw 'FXStage.getSourceTexture() No source texture!';
};

FXStage.prototype.drawFullScreenQuad = function(width, height, image, program) {
  this.drawFullScreenQuadAt(0, 0, width, height, image, program);
};

FXStage.prototype.drawFullScreenQuadAt = function(x, y, width, height, image, program) {
  var gl = this.gl;
  gl.disable(gl.DEPTH_TEST);
  var oldViewport = gl.getParameter(gl.VIEWPORT);

  glu.viewport(x, y, width, height, false);
  this.fullscreenQuad.draw(image, program);
  glu.viewport(oldViewport[0], oldViewport[1], oldViewport[2], oldViewport[3], false);
};

FXStage.prototype.getImage = function(path) {
  var resProps = { path: path };
  var res = this.resourceMgr.getResource('Image', resProps);
  if (!res) {
    var image = Texture2D.load(path);
    res = this.resourceMgr.addResource('Image', image, resProps);
  }
  res.used = false;

  return res.obj;
};

FXStage.prototype.getFullScreenQuad = function() {
  return this.fullscreenQuad;
};

module.exports = FXStage;