着色器编译错误

Question

I am working on a project that has shaders hidden in the source code. I received this error (at runtime):

Error compiling vertex shader:

Full VS shader source:

//precision highp float;

uniform vec2 uEyeToSourceUVScale;
uniform vec2 uEyeToSourceUVOffset;

attribute vec4 aPosition;         ///< [-1,+1],[-1,+1] over the entire framebuffer. Lerp factor in Pos.z. Vignette fade factorin Pos.w.
attribute vec2 aTanEyeAnglesR;   ///< The tangents of the horizontal and vertical eye angles for the red channel.
attribute vec2 aTanEyeAnglesG;   ///< The tangents of the horizontal and vertical eye angles for the green channel.
attribute vec2 aTanEyeAnglesB;   ///< The tangents of the horizontal and vertical eye angles for the blue channel.

varying vec4 vPosition; 
varying vec2 vTexCoordR; 
varying vec2 vTexCoordG; 
varying vec2 vTexCoordB; 

void main(void)
{
    vPosition = aPosition;
    vTexCoordR = aTanEyeAnglesR * uEyeToSourceUVScale + uEyeToSourceUVOffset;
    vTexCoordG = aTanEyeAnglesG * uEyeToSourceUVScale + uEyeToSourceUVOffset;
    vTexCoordB = aTanEyeAnglesB * uEyeToSourceUVScale + uEyeToSourceUVOffset;
    vTexCoordR.y = 1.0 - vTexCoordR.y;
    vTexCoordG.y = 1.0 - vTexCoordG.y;
    vTexCoordB.y = 1.0 - vTexCoordB.y;
    gl_Position = vec4(aPosition.xy, 0, 1);
}

Shader compilation failed.

I don't know how to approach solving this problem (no shader experience); however, I know shader code is similar to C++ code and in that sense this looks very straightforwardly correct to me (unless I'm missing something).

Is there something obviously wrong with this shader code?

Answer 1

The lack of a #version directive implies #version 110 .

gl_Position = vec4(aPosition.xy, 0, 1);
                                 ^  ^ int literals

#version 110 doesn't support automatic int -> float conversion. Use float literals instead:

gl_Position = vec4(aPosition.xy, 0.0, 1.0);
                                 ^^^  ^^^ float literals