Skip to content

The Shader Program Handler

ShaderProgram

ShaderProgram encapsulates the handling of shaders by interacting directly with an OpenGL context provided by moderngl.

Parameters:

Name Type Description Default
opengl_context Context

The OpenGL context.

 required
shader_dir str

The directory containing the vertex and fragment shader source code files.

 required
Source code in pynecraft/shader_program.py 
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
class ShaderProgram:
    """ShaderProgram encapsulates the handling of shaders by interacting
    directly with an OpenGL context provided by moderngl.

    Args:
        opengl_context (moderngl.Context): The OpenGL context.
        shader_dir (str): The directory containing the vertex and fragment
            shader source code files.
    """

    def __init__(
        self,
        opengl_context: moderngl.Context,
        player: FirstPersonPlayer,
        shader_dir: str,
    ) -> None:
        self.opengl_context = opengl_context
        self.player = player

        self.program = self.get_program(shader_dir=shader_dir)
        self.set_uniforms()

    def get_program(self, shader_dir: str) -> moderngl.Program:
        """Create a shader program from the vertex and fragment shader source

        Args:
            shader_dir (str): The directory containing the vertex and fragment
                shader source code files.
        """
        assert os.path.isdir(
            shader_dir
        ), f"Shader directory '{shader_dir}' does not exist."

        with open(os.path.join(shader_dir, "vertex_shader.glsl"), "r") as file:
            vertex_shader_source = file.read()

        with open(os.path.join(shader_dir, "fragment_shader.glsl"), "r") as file:
            fragment_shader_source = file.read()

        return self.opengl_context.program(
            vertex_shader=vertex_shader_source, fragment_shader=fragment_shader_source
        )

    def set_uniforms(self):
        """Set the uniform variables of the shader program, the values of which
        remain constant for all vertices processed during a single draw call.
        """
        # Set the projection matrix uniform variable to the vertex shader
        self.program["m_proj"].write(self.player.projection_matrix)
        # Set the model matrix uniform variable to the vertex shader
        self.program["m_model"].write(glm.mat4())

    def update(self):
        """Update the uniform variables of the shader program."""
        # Set the view matrix uniform variable to the vertex shader
        self.program["m_view"].write(self.player.view_matrix)

get_program(shader_dir)

Create a shader program from the vertex and fragment shader source

Parameters:

Name Type Description Default
shader_dir str

The directory containing the vertex and fragment shader source code files.

 required
Source code in pynecraft/shader_program.py 
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
def get_program(self, shader_dir: str) -> moderngl.Program:
    """Create a shader program from the vertex and fragment shader source

    Args:
        shader_dir (str): The directory containing the vertex and fragment
            shader source code files.
    """
    assert os.path.isdir(
        shader_dir
    ), f"Shader directory '{shader_dir}' does not exist."

    with open(os.path.join(shader_dir, "vertex_shader.glsl"), "r") as file:
        vertex_shader_source = file.read()

    with open(os.path.join(shader_dir, "fragment_shader.glsl"), "r") as file:
        fragment_shader_source = file.read()

    return self.opengl_context.program(
        vertex_shader=vertex_shader_source, fragment_shader=fragment_shader_source
    )

set_uniforms()

Set the uniform variables of the shader program, the values of which remain constant for all vertices processed during a single draw call.

Source code in pynecraft/shader_program.py 
52
53
54
55
56
57
58
59
def set_uniforms(self):
    """Set the uniform variables of the shader program, the values of which
    remain constant for all vertices processed during a single draw call.
    """
    # Set the projection matrix uniform variable to the vertex shader
    self.program["m_proj"].write(self.player.projection_matrix)
    # Set the model matrix uniform variable to the vertex shader
    self.program["m_model"].write(glm.mat4())

update()

Update the uniform variables of the shader program.

Source code in pynecraft/shader_program.py 
61
62
63
64
def update(self):
    """Update the uniform variables of the shader program."""
    # Set the view matrix uniform variable to the vertex shader
    self.program["m_view"].write(self.player.view_matrix)