demosys.opengl package

Submodules

demosys.opengl.fbo module

class demosys.opengl.fbo.FBO

Bases: object

Frame buffer object

add_color_attachment(texture)

Add a texture as a color attachment.

Parameters:texture – The Texture object
bind(stack=True)

Bind FBO adding it to the stack.

Parameters:stack – (bool) If the bind should push the current FBO on the stack.
check_status()

Checks the completeness of the FBO

clear()

Clears the FBO using glClear.

classmethod create(width, height, depth=False, stencil=True, internal_format=GL_RGBA8, format=GL_RGBA, type=GL_UNSIGNED_BYTE)

Convenient shortcut for creating single color attachment FBOs

Parameters:
  • width – Color buffer width
  • height – Coller buffer height
  • depth – (bool) Create a depth attachment
  • stencil – (bool) Create a stencil attachment
  • internal_format – The internalformat of the color buffer
  • format – The format of the color buffer
  • type – The type of the color buffer
Returns:

A new FBO
release(stack=True)

Bind FBO popping it from the stack

Parameters:stack – (bool) If the bind should be popped form the FBO stack.
set_depth_attachment(texture)

Set a texture as depth attachment.

Parameters:texture – The Texture object
size

Attempts to determine the pixel size of the FBO. Currently returns the size of the first color attachment. If the FBO has no color attachments, the depth attachment will be used. Raises `FBOError if the size cannot be determined.

Returns:(w, h) tuple representing the size in pixels
exception demosys.opengl.fbo.FBOError

Bases: Exception

Generic FBO Error

class demosys.opengl.fbo.WindowFBO

Bases: object

Fake FBO representing default render target

bind()

Sets the viewport back to the buffer size of the screen/window

clear()

Dummy clear method.

release()

Dummy release method.

demosys.opengl.fbo.pop_fbo(fbo)

Pops the fbo out of the stack Returns: The last last fbo in the stack

demosys.opengl.fbo.push_fbo(fbo)

Push fbo into the stack

demosys.opengl.shader module

class demosys.opengl.shader.Attribute(name, type, location)

Bases: object

Stores information about a shader attribute

class demosys.opengl.shader.Shader(path)

Bases: object

Represents a shader program

bind()

Bind the shader

build_attribute_map()

Builds an internal attribute map by querying the program. This way we don’t have to query OpenGL (can cause slowdowns) This information is also used when the shader and VAO negotiates the buffer binding.

build_uniform_map()

Builds an internal uniform map by querying the program. This way we don’t have to query OpenGL (can cause slowdowns)

Links the program. Raises ShaderError if the linker failed.

prepare()

Compiles all the shaders and links the program. If the linking is successful, it builds the uniform and attribute map.

set_fragment_source(source)

Set the fragment shader source

Parameters:source – (string) Fragment shader source
set_geometry_source(source)

Set the geometry shader source

Parameters:source – (string) Geometry shader source
set_source(source)

Set a single source file. This is used when you have all shaders in one file separated by preprocessors.

Parameters:source – (string) The shader source
set_vertex_source(source)

Set the vertex shader source

Parameters:source – (string) Vertex shader source
uniform(name)

Get the uniform location. Raises ShaderError if the uniform is not found.

Parameters:name – The name of the uniform
Returns:Uniform object
uniform_1f(name, value)

Set a float uniform

Parameters:
  • name – Name of the uniform
  • value – float value
uniform_2f(name, x, y)

Set a vec2 uniform

Parameters:
  • name – name of the uniform
  • x – float value
  • y – float value
uniform_3f(name, x, y, z)

Set a vec3 uniform

Parameters:
  • name – Name of the uniform
  • x – float value
  • y – float value
  • z – float value
uniform_4f(name, x, y, z, w)

Set a vec4 uniform

Parameters:
  • name – Name of the uniform
  • x – float value
  • y – float value
  • z – float value
  • w – float value
uniform_check(name, expected_type)

Get a uniform and verify the expected type. This is used by the uniform_* methods for validating the actual type in the shader and the uniform we are trying to set. Raises ShaderError if the uniform is not found.

Parameters:
  • name – The name of the uniform
  • expected_type – The expected type of the uniform.
Returns:

The Uniform object
uniform_mat3(name, mat)

Sets a mat3 uniform

Parameters:
  • name – Name of the uniform
  • mat – matrix
uniform_mat4(name, mat)

Set a mat4 uniform

Parameters:
  • name – Name of the uniform
  • mat – matrix
uniform_sampler_1d(unit, name, texture)

Sets a sampler1d

Parameters:
  • unit – The texture unit to use (0 - N)
  • name – Name of the uniform
  • texture – The Texture object
uniform_sampler_2d(unit, name, texture)

Sets a sampler2d

Parameters:
  • unit – The texture unit to use (0 - N)
  • name – Name of the uniform
  • texture – The Texture object
exception demosys.opengl.shader.ShaderError

Bases: Exception

class demosys.opengl.shader.ShaderSource(type, name, source)

Bases: object

Helper class to deal with shader source files. This represents a single shader (vert/frag/geo)

compile()

Compile the shader

print()

Print the shader lines

type_name()

Returns a string representation of the shader type

class demosys.opengl.shader.TypeInfo(name, value, size)

Bases: object

Information about a data type in a glsl shader.

Example: “GL_FLOAT_VEC3” is a GL.GL_FLOAT_VEC3 of byte size 12

class demosys.opengl.shader.Uniform(name, size, type, location)

Bases: object

Stores information about a uniform

demosys.opengl.texture module

class demosys.opengl.texture.Texture

Bases: object

Represents a texture

bind()

Binds the texture to the currently active texture unit

classmethod create_2d(width, height, internal_format=GL_RGBA8, format=GL_RGBA, type=GL_UNSIGNED_BYTE)

Creates a 2d texture

Parameters:
  • width – Width of the texture
  • height – height of the texture
  • internal_format – Internal format
  • format – Format
  • type – Type
Returns:

Texture object
classmethod from_image(path, image=None)

Creates and image from a image file using Pillow/PIL

Parameters:
  • path – The path to the file
  • image – The PIL/Pillow image object
Returns:

Texture object
set_image(image)

Set pixel data using a image file with PIL/Pillow.

Parameters:image – The PIL/Pillow image object
set_interpolation(mode)

Sets the texture interpolation mode

Parameters:mode – Interpolation mode (gl enum)
set_texture_repeat(mode)

Sets the texture repeat mode

Parameters:mode – Repeat mode (gl enum)
size

Get the dimensions of the texture

Returns:(w, h) tuple

demosys.opengl.vao module

class demosys.opengl.vao.ArrayBuffer(format, vbo)

Bases: object

Container for a vbo with additional information

size
Returns:Size of the vbo in bytes
target
Returns:Returns the trarget of the vbo. GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER etc
usage
Returns:The usage of the vbo. GL_DYNAMIC_DRAW / GL_STATIC_DRAW
vertices
Returns:The number of vertices based on the current stride
class demosys.opengl.vao.ArrayMapping(array_buffer, attrib_name, components, offset)

Bases: object

Keeps track of vbo to attribute mapping

class demosys.opengl.vao.VAO(name, mode=GL_TRIANGLES)

Bases: object

Vertex Array Object

add_array_buffer(format, vbo)

Register a vbo in the VAO. This can be called multiple times. This can be one or multiple buffers (interleaved or not)

Parameters:
  • format – The format of the buffer
  • vbo – The vbo object
bind(shader)

Bind the VAO using a shader. This is the standard way of binding so the shader and VAO can negotiate the needed attributes. This will generate new VAOs in the background on the fly (caching them) if needed.

Parameters:shader – The shader
Returns:A VAOBindContext object (optional use)
build()

Finalize the VAO. This runs various sanity checks on the input data.

draw(mode=None)

Draw the VAO. Will use glDrawElements if an element buffer is present and glDrawArrays if no element array is present.

Parameters:mode – Override the draw mode (GL_TRIANGLES etc)
generate_vao_combo(shader)

Create a VAO based on the shader’s attribute specification. This is called by bind(shader) and should not be messed with unless you are absolutely sure about what you are doing.

Parameters:shader – The shader we are generating the combo for
Returns:A new VAOCombo object with the correct attribute binding
map_buffer(vbo, attrib_name, components)

Map parts of the vbos to an attribute name. This can be called multiple times to describe hos the buffers map to attribute names. If the same vbo is passed more than once it must be an interleaved buffer.

Parameters:
  • vbo – The vbo
  • attrib_name – Name of the attribute in the shader
  • components – Number of components (for example 3 for a x, y, x position)
set_element_buffer(format, vbo)

Set the index buffer for this VAO

Parameters:
  • format – The format of the element buffer
  • vbo – the vbo object
class demosys.opengl.vao.VAOBindContext(vao)

Bases: object

Context managers for bound VAOs

class demosys.opengl.vao.VAOCombo(key)

Bases: object

VAO of a specific attribute configuration. These are the actual VAOs used when drawing.

add_array_mapping(mapping)

Add ArrayMappings relevant to this VAO version

Parameters:mapping – The ArrayMapping to add
bind()

Bind the VAO

exception demosys.opengl.vao.VAOError

Bases: Exception

demosys.opengl.vao.type_size(format)

Determines the byte size of a format

Module contents