GLSL 1.0.0 - 在顶点和片段着色器中使用“变化”时遇到麻烦

Question

I'm developing using OpenGL ES 2.0.0 and GLSL ES 1.0.0.

Currently I'm rendering a square to screen to the screen, and now attempting to apply a texture.

I'm having trouble using " varying " in vertex and fragment shaders, receiving the error message:

- Failed to compile vertex shader - 
0(3) : error C5060: out can't be used with non-varying tex_varying

in vec4 texture_coord ;
in vec4 position ;
out vec2 tex_varying ;
uniform mat4 translate ;
void main ( ) 
{
  gl_Position = translate * position ;
  tex_varying = texture_coord . xy ;
}

I've read through the documentation and can't figure out what I'm doing wrong.

Here's the code.

Vertex:

attribute vec4 position; 
attribute vec4 texture_coord; 
varying vec2 tex_varying; 
uniform mat4 translate; 

void main()
{ 
  gl_Position = translate * position; 
  tex_varying = texture_coord.xy;
}

Fragment:

varying vec2 tex_varying; 
uniform sampler2D texture; 

void main()
{
  gl_FragColor = texture2D(texture, tex_varying);
}

RESOLVED: This is a late reply, but I ended up solving this problem a long time ago - in case anyone else stumbles across the issue. It turns out "tex_varying" is reserved by Nvidia! Simply renaming tex_varying solved the issue.

Cheers.

Answer 1

The in and out keywords as you show them are for GLSL v3 and later. For v1 (which is what you're trying to use?) you need to replace in with attribute and out with varying in the vertex shader. In the fragment shader, replace in with varying and you can't use out -- you need to output to gl_FragColor as you seem to be doing.

So your 2nd/3rd shaders look like you've correctly translated the GLSL v3 code in the first shader to GLSL v1, and look like they should work with ES2/GLSL v1