"Scan Through" a large texture glsl - glsl

Question

I've encoded some data into a 44487x1.0 luminance texture:
Now I would like to "scrub" this data across my shader, so that a slice of the texture equal in width to the pixel width of my canvas is displayed. So if the canvas is 500px wide, then 500 pixels from the texture will be shown. The texture is then translated by some offset value so that different values within the texture can be displayed.
//vertex shader
export const vs = GLSL`
#version 300 es
in vec4 position;
void main() {
gl_Position = position;
}
`;
//fragment shader
#version 300 es
#ifdef GL_ES
precision highp float;
#endif
uniform vec2 u_resolution;
uniform float u_time;
uniform sampler2D u_texture_7; //data texture
out vec4 fragColor;
void main(){
//data texture dimensions
vec2 dims = vec2(44487., 1.0);
//amount by which to translate the data texture
vec2 offset = vec2(u_time*.5, 0.);
//canvas coords
vec2 uv = gl_FragCoord.xy/u_resolution.xy;
//textuer asspect ratio, w/h
float textureAspect = 44487. / 1.;
vec3 col = vec3(0.);
//texture width is 44487*larger than uv, I guess?
vec2 textCoords = vec2((uv.x/textureAspect)+offset.x, uv.y);
//get texture values
vec3 text = texture(u_texture_7, textCoords).rgb;
//output
fragColor = vec4(text, 1.);
}
However, this doesn't seem to work. All I get is a black screen. Is using a wide texture like this a good way to go about getting the array values into the shader? The texture is very small in size, but I'm wondering if the dimensions might still be causing an issue.
Alternatively to providing one large texture, I could provide a smaller texture, but update the texture uniform values via js?

Answer 1

After trying several different approaches, the work around I ended up using was uploading the 44487x1.0 image to a separate 2d canvas, and then performing the transformations of the texture in the 2d canvas, and not the shader. The canvas is then sent to the shader as a texture.
Might not be the most efficient solution, but it avoids having to mess around with the texture too much in the shader.