CODEWITHSUNDEEP
iphoneios6opengl-es-2.0
Justin
Justin

Reputation: 2142

GLSL fragment shader will not compile

I am completely stumped here. I have the following fragment shader working:

varying lowp vec4 fposition;
varying lowp vec4 fcolor;
varying lowp vec2 ftexturecoordinates;


void main() {
    gl_FragColor = fcolor;
}

If I try to add anything at all (example: vec4 light position = vec4(-2.0, 2.0, 1.0, 1.0)), it will not compile. I cannot figure out how to get error codes/descriptions, but I cannot get any of the normal OpenGL ES shaders to work. I have the same shader compilation code in this app as I have in all my other apps, so I know that section works fine. What, if anything, can I do to find information on the problem?

Upvotes: 1

Views: 1176

Answers (1)

haffax
haffax

Reputation: 6008

After you compiled a shader, you can check the GL_COMPILE_STATUS if it is GL_FALSE, you can use use glGetShaderInfoLog to get additional information on the compile error.

Here is a snippet that shows how to use glGetShaderInfoLog:

(I left the project specific error checking in for reference, but commented it out, as it wont work without the framework around it.)

glCompileShader(shader);
//mada_check_gl_error();

GLint compiled;
glGetShaderiv(shader, GL_COMPILE_STATUS, &compiled);
//mada_check_gl_error();
if (!compiled)
{
    GLint length;
    glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &length);
    //mada_check_gl_error();
    if (length > 0)
    {
        GLint infoLength;
        char* infoBuf = (char*) malloc(sizeof(char) * length);
        glGetShaderInfoLog(shader, length, &infoLength, infoBuf);
        //mada_check_gl_error();
        //mada_log(logERROR, infoBuf);
        free(infoBuf);
        //SysUtils::error("Error compiling shader. See log for info.");
    }
    //SysUtils::error("Failed to compile shader. No further info available.");
}

Upvotes: 3

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