All files / engine/Source/Scene PickDepth.js

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1x
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1x
 
 
 
 
1x
1x
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1x
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1x
 
 
 
1x
 
 
 
1x
 
 
 
 
 
 
 
 
 
 
 
import Cartesian4 from "../Core/Cartesian4.js";
import defined from "../Core/defined.js";
import destroyObject from "../Core/destroyObject.js";
import FramebufferManager from "../Renderer/FramebufferManager.js";
import RenderState from "../Renderer/RenderState.js";
 
/**
 * @alias PickDepth
 * @constructor
 *
 * @private
 */
function PickDepth() {
  this._framebuffer = new FramebufferManager();
 
  this._textureToCopy = undefined;
  this._copyDepthCommand = undefined;
}
 
Object.defineProperties(PickDepth.prototype, {
  framebuffer: {
    get: function () {
      return this._framebuffer.framebuffer;
    },
  },
});
 
function updateFramebuffers(pickDepth, context, depthTexture) {
  const { width, height } = depthTexture;
  pickDepth._framebuffer.update(context, width, height);
}
 
function updateCopyCommands(pickDepth, context, depthTexture) {
  if (!defined(pickDepth._copyDepthCommand)) {
    pickDepth._copyDepthCommand = context.createViewportQuadCommand(
      `uniform highp sampler2D colorTexture;
 
in vec2 v_textureCoordinates;
 
void main()
{
  vec4 globeDepthPacked = texture(czm_globeDepthTexture, v_textureCoordinates);
  float globeDepth = czm_unpackDepth(globeDepthPacked);
  float depth = texture(colorTexture, v_textureCoordinates).r;
  out_FragColor = czm_branchFreeTernary(globeDepth <= 0.0 || globeDepth >= 1.0 || depth < globeDepth && depth > 0.0 && depth < 1.0,
    czm_packDepth(depth), globeDepthPacked);
}
`,
      {
        renderState: RenderState.fromCache(),
        uniformMap: {
          colorTexture: function () {
            return pickDepth._textureToCopy;
          },
        },
        owner: pickDepth,
      },
    );
  }
 
  pickDepth._textureToCopy = depthTexture;
  pickDepth._copyDepthCommand.framebuffer = pickDepth.framebuffer;
}
 
PickDepth.prototype.update = function (context, depthTexture) {
  updateFramebuffers(this, context, depthTexture);
  updateCopyCommands(this, context, depthTexture);
};
 
const scratchPackedDepth = new Cartesian4();
const packedDepthScale = new Cartesian4(
  1.0,
  1.0 / 255.0,
  1.0 / 65025.0,
  1.0 / 16581375.0,
);
 
/**
 * Read the depth from the framebuffer at the given coordinate.
 *
 * @param {Context} context
 * @param {number} x The x-coordinate at which to read the depth.
 * @param {number} y The y-coordinate at which to read the depth.
 * @returns {number} The depth read from the framebuffer.
 *
 * @private
 */
PickDepth.prototype.getDepth = function (context, x, y) {
  // If this function is called before the framebuffer is created, the depth is undefined.
  if (!defined(this.framebuffer)) {
    return undefined;
  }
 
  const pixels = context.readPixels({
    x: x,
    y: y,
    width: 1,
    height: 1,
    framebuffer: this.framebuffer,
  });
 
  const packedDepth = Cartesian4.unpack(pixels, 0, scratchPackedDepth);
  Cartesian4.divideByScalar(packedDepth, 255.0, packedDepth);
  return Cartesian4.dot(packedDepth, packedDepthScale);
};
 
PickDepth.prototype.executeCopyDepth = function (context, passState) {
  this._copyDepthCommand.execute(context, passState);
};
 
PickDepth.prototype.isDestroyed = function () {
  return false;
};
 
PickDepth.prototype.destroy = function () {
  this._framebuffer.destroy();
  if (defined(this._copyDepthCommand)) {
    this._copyDepthCommand.shaderProgram =
      defined(this._copyDepthCommand.shaderProgram) &&
      this._copyDepthCommand.shaderProgram.destroy();
  }
 
  return destroyObject(this);
};
export default PickDepth;