1. fieldanimation Package

fieldanimation classes:

fieldanimation.glInfo()

Return OpenGL information dict WARNING: OpenGL context MUST be initialized !!!

Parameters:None – Returns:OpenGL information dict

fieldanimation.field2RGB(field)

Return 2D field converted to uint8 RGB image (i.e. scaled in [0, 255])

Parameters:field (numpy.ndarray) – (u, v) 2D vector field instance Returns:( rgb (numpy.ndarray): uint8 RGB image, uMin (float): u min, uMax (float): u max, vMin (float): v min, vMax (float): v max, ) (tuple): Return value

fieldanimation.modulus(field)

Return normalized modulus of 2D field image

Returns:normalized modulus of 2D field image (i.e. scaled in [0, 1.])

class fieldanimation.FieldAnimation(width, height, field, computeSahder=False, image=None)

Bases: object

Field Animation with OpenGL

1. draw the modulus of the vector field or a user defined image

   if requested;

2. set a framebuffer texture (screen texture) as the main

   rendering target:

   1. draw the background texture on the screen texture with a fixed opacity;
   2. decode the particles positions from the currentTracersPosition texture and draw them on the screen texture;

3. set the rendering target to the active window;
4. draw screen texture on the active window;
5. swap screen texture and background texture;

6. calculate the new particles positions

   (in the update shader) and encode them in the nextTracersPosition texture;

7. swap nextTracersPosition texture and

   currentTracersPosition texture;

__init__(width, height, field, computeSahder=False, image=None)

Animate 2D vector field

Parameters:

• width (int) – width in pixels
• height (int) – height in pixels
• field (np.ndarray) – 2D vector field
• = True selects the compute shader version (cs) –
• = Optional background image (image) –

setField(field)

Set the 2D vector field. Must be called every time a new vetor field is selected.

Parameters:field (np.ndarray) – 2D vector field

setRenderingTarget(texture)

Set texture as rendering target

Parameters:(class (texture) – texture instance): 2D vector field

setSize(width, height)

Set instance size. Must be called when the window is resized.

Parameters:

• width (int) – window width in pixels
• height (int) – window height in pixels

resetRenderingTarget()

Bind first (default) framebuffer and reset the viewport.

tracersCount

Return tracers count

Returns:number of tracers

_initTracers()

Initialize the tracers positions

draw()

Render the OpenGL scene. This method is called automatically when the scene has to be rendered and is responsible for the animation.

drawScreen()

Draw background texture and tracers on screen framebuffer texture

drawModulus(opacity)

Draw the modulus texture.

Parameters:opacity (float) – opacity (alpha) of the texture: 0 –> transparent 1 –> opaque

drawImage()

Draw an image texture in background.

drawTexture(texture, opacity)

Draw texture on the screen.

Parameters:

• ( (texture) – class:Texture): texture instance
• opacity (float) – opacity (alpha) of the texture 0 –> transparent 1 –> opaque

drawTracers()

Draw the tracers on the screen

updateTracers()

Update tracers position using the fragment shader provided by the graphic card for computing.

updateTracersCS()

Update tracers position using the compute shader provided by the graphic card for computing.

1.1. shader Module

shader classes:

class fieldanimation.shader.Shader(path=None, **kargs)

Bases: object

Base shader class

__init__(path=None, **kargs)

addUniform(uniform, utype=None)

Add a uniform variable to the shader. If utype is not none it defines the setter function. Valid utypes are i, b, f, 2f, 4fv

addUniforms(uniformlist)

_build_shader(sourceCode, shader_type)

Actual building of the shader

delete()

_link()

Link the program

bind()

Bind the program, i.e. use it

unbind()

Unbind whatever program is currently bound - not necessarily this program, so this should probably be a class method instead.

setUniform(name, value)

setUniforms(nameandvalue)

code(shader='v', lineno=False)

Return shader code.

Keyword Arguments:  

• shader (string) – v for vertex, f for fragment, g for geometry
• lineno (boolean) – add line numbers to code

Returns:

shader source code

vertex_code(lineno=False)

Return vertex shader code with optional line numbers

fragment_code(lineno=False)

Return fragment shader code with optional line numbers

geometry_code(lineno=False)

Return geometry shader code with optional line numbers

1.2. texture Module

texture classes:

class fieldanimation.texture.Texture(data=None, width=None, height=None, filt=GL_NEAREST, dtype=GL_UNSIGNED_BYTE)

Bases: object

__init__(data=None, width=None, height=None, filt=GL_NEAREST, dtype=GL_UNSIGNED_BYTE)

Texture object. If data is None an empty texture will be created

bind(texUnit=0)

handle()

unbind()