Function loadShader

lib/renderer/gl/framework.py:15–46

(shaderType, shaderFile)

# Function that creates and compiles shaders according to the given type (a GL enum value) and
# shader program (a file containing a GLSL program).
def loadShader(shaderType, shaderFile):
    # check if file exists, get full path name
    strFilename = findFileOrThrow(shaderFile)
    shaderData = None
    with open(strFilename, 'r') as f:
        shaderData = f.read()

    shader = glCreateShader(shaderType)
    glShaderSource(shader, shaderData)  # note that this is a simpler function call than in C

    # This shader compilation is more explicit than the one used in
    # framework.cpp, which relies on a glutil wrapper function.
    # This is made explicit here mainly to decrease dependence on pyOpenGL
    # utilities and wrappers, which docs caution may change in future versions.
    glCompileShader(shader)

    status = glGetShaderiv(shader, GL_COMPILE_STATUS)
    if status == GL_FALSE:
        # Note that getting the error log is much simpler in Python than in C/C++
        # and does not require explicit handling of the string buffer
        strInfoLog = glGetShaderInfoLog(shader)
        strShaderType = ""
        if shaderType is GL_VERTEX_SHADER:
            strShaderType = "vertex"
        elif shaderType is GL_GEOMETRY_SHADER:
            strShaderType = "geometry"
        elif shaderType is GL_FRAGMENT_SHADER:
            strShaderType = "fragment"

        print("Compilation failure for " + strShaderType + " shader:\n" + str(strInfoLog))

    return shader


# Function that accepts a list of shaders, compiles them, and returns a handle to the compiled program