Context : I pass a uniform array of float to my fragment shader, then initialize a float with a value from this array, and finally try to increment this float in for loop, with this code :
var regl = createREGL()
var drawTriangle = regl({
vert: `
precision mediump float;
attribute vec2 position;
void main () {
gl_Position = vec4(position, 0, 1);
}
`,
frag: `
precision mediump float;
uniform float refPoints[3];
varying vec3 fcolor;
void main () {
float a_value = refPoints[1];
for(int i=0;i<3;++i) {
a_value += 1.; // <-- this line is causing the error
}
gl_FragColor = vec4(1, 1, 1, 1);
}
`,
attributes: {
position: [
[1, 0],
[0, 1],
[-1, -1]
],
},
uniforms : {
refPoints : [0., 1., 0., 2.]
},
count: 3
})
regl.frame(function () {
regl.clear({
color: [0, 0, 0, 1],
depth: 1
})
drawTriangle()
})
<script src="https://npmcdn.com/regl/dist/regl.js"></script>
I am having a weird error :
Error: (regl) bad data or missing for uniform "refPoints[0]". invalid type, expected number in command unknown
I don't understand why this increment in this particular loop is causing so much trouble. Do you have any ideas ?
AFAICT it's a bug in regl? It works if you use
uniforms: {
"refPoints[0]": 0.,
"refPoints[1]": 1.,
"refPoints[2]": 0.,
}
var regl = createREGL()
var drawTriangle = regl({
vert: `
precision mediump float;
attribute vec2 position;
void main () {
gl_Position = vec4(position, 0, 1);
}
`,
frag: `
precision mediump float;
uniform float refPoints[3];
varying vec3 fcolor;
void main () {
float a_value = refPoints[1];
for(int i=0;i<3;++i) {
a_value += 1.; // <-- this line is causing the error
}
gl_FragColor = vec4(1, 1, 1, 1);
}
`,
attributes: {
position: [
[1, 0],
[0, 1],
[-1, -1]
],
},
uniforms : {
"refPoints[0]" : 0.,
"refPoints[1]" : 1.,
"refPoints[2]" : 0.,
},
count: 3
})
regl.frame(function () {
regl.clear({
color: [0, 0, 0, 1],
depth: 1
})
drawTriangle()
})
<script src="https://npmcdn.com/regl/dist/regl.js"></script>