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# -*- coding: utf-8 -*-
# vispy: testskip
# -----------------------------------------------------------------------------
# Copyright (c) Vispy Development Team. All Rights Reserved.
# Distributed under the (new) BSD License. See LICENSE.txt for more info.
# -----------------------------------------------------------------------------
"""
Demo of jump flooding algoritm for EDT using GLSL
Author: Stefan Gustavson (stefan.gustavson@gmail.com)
2010-08-24. This code is in the public domain.
Adapted to `vispy` by Eric Larson <larson.eric.d@gmail.com>.
This version is a translation of the OSX C code to Python.
Two modifications were made for OpenGL ES 2.0 compatibility:
1. GL_CLAMP_TO_BORDER was changed to GL_CLAMP_TO_EDGE, with
corresponding shader changes.
2. GL_RG16 was changed to GL_RGBA with corresponding shader changes
(including hard-coding "texlevels" at 65536).
"""
import numpy as np
from os import path as op
from vispy.ext import glfw
from vispy.io import load_data_file
from OpenGL import GL as gl
from OpenGL import GLU as glu
from PIL import Image
import time
this_dir = op.abspath(op.dirname(__file__))
def createShader(vert_fname, frag_fname):
"""createShader - create, load, compile and link the shader object"""
with open(op.join(this_dir, vert_fname), 'rb') as fid:
vert = fid.read().decode('ASCII')
with open(op.join(this_dir, frag_fname), 'rb') as fid:
frag = fid.read().decode('ASCII')
vertexShader = gl.glCreateShader(gl.GL_VERTEX_SHADER)
gl.glShaderSource(vertexShader, vert)
gl.glCompileShader(vertexShader)
fragmentShader = gl.glCreateShader(gl.GL_FRAGMENT_SHADER)
gl.glShaderSource(fragmentShader, frag)
gl.glCompileShader(fragmentShader)
programObj = gl.glCreateProgram()
gl.glAttachShader(programObj, vertexShader)
gl.glAttachShader(programObj, fragmentShader)
gl.glLinkProgram(programObj)
checkGLError()
return programObj
def setUniformVariables(programObj, texture, texw, texh, step):
"""setUniformVariables - set the uniform shader variables we need"""
gl.glUseProgram(programObj)
location_texture = gl.glGetUniformLocation(programObj, "texture")
if location_texture != -1:
gl.glUniform1i(location_texture, texture)
location_texw = gl.glGetUniformLocation(programObj, "texw")
if location_texw != -1:
gl.glUniform1f(location_texw, texw)
location_texh = gl.glGetUniformLocation(programObj, "texh")
if location_texh != -1:
gl.glUniform1f(location_texh, texh)
location_step = gl.glGetUniformLocation(programObj, "step")
if(location_step != -1):
gl.glUniform1f(location_step, step)
gl.glUseProgram(0)
checkGLError()
def loadImage(filename): # adapted for Python
img = Image.open(filename)
w, h = img.size
x = np.array(img)[::-1].tostring()
assert len(x) == w * h
return x, w, h
def loadShapeTexture(filename, texID):
"""loadShapeTexture - load 8-bit shape texture data
from a TGA file and set up the corresponding texture object."""
data, texw, texh = loadImage(load_data_file('jfa/' + filename))
gl.glActiveTexture(gl.GL_TEXTURE0)
gl.glBindTexture(gl.GL_TEXTURE_2D, texID)
# Load image into texture
gl.glTexImage2D(gl.GL_TEXTURE_2D, 0, gl.GL_LUMINANCE, texw, texh, 0,
gl.GL_LUMINANCE, gl.GL_UNSIGNED_BYTE, data)
# This is the input image. We want unaltered 1-to-1 pixel values,
# so specify nearest neighbor sampling to be sure.
gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MIN_FILTER,
gl.GL_NEAREST)
gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MAG_FILTER,
gl.GL_NEAREST)
gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_S, gl.GL_REPEAT)
gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_T, gl.GL_REPEAT)
checkGLError()
return texw, texh
def createBufferTexture(texID, texw, texh):
"""createBufferTexture - create an 8-bit texture render target"""
gl.glActiveTexture(gl.GL_TEXTURE0)
gl.glBindTexture(gl.GL_TEXTURE_2D, texID)
black = (0., 0., 0., 0.)
# The special shader used to render this texture performs a
# per-pixel image processing where point sampling is required,
# so specify nearest neighbor sampling.
#
# Also, the flood fill shader handles its own edge clamping, so
# texture mode GL_REPEAT is inconsequential. "Zero outside" would
# be useful, but separate edge values are deprecated in OpenGL.
#
gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MIN_FILTER,
gl.GL_NEAREST)
gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_MAG_FILTER,
gl.GL_NEAREST)
gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_S,
gl.GL_CLAMP_TO_EDGE)
gl.glTexParameteri(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_WRAP_T,
gl.GL_CLAMP_TO_EDGE)
gl.glTexParameterfv(gl.GL_TEXTURE_2D, gl.GL_TEXTURE_BORDER_COLOR, black)
gl.glTexImage2D(gl.GL_TEXTURE_2D, 0, gl.GL_RGBA, texw, texh, 0,
gl.GL_RGBA, gl.GL_UNSIGNED_BYTE, '\x00' * texw*texh*4)
gl.glBindTexture(gl.GL_TEXTURE_2D, 0)
checkGLError()
t0 = 0.0
frames = 0
def showFPS(texw, texh):
"""showFPS - Calculate and report texture size and frames per second
in the window title bar (updated once per second)"""
global frames, t0
t = time.time()
if (t - t0) > 1.:
fps = frames / (t - t0)
titlestr = "%sx%s texture, %.1f FPS" % (texw, texh, fps)
glfw.glfwSetWindowTitle(window, titlestr)
t0 = t
frames = 0
frames += 1
def checkGLError():
status = gl.glGetError()
if status != gl.GL_NO_ERROR:
raise RuntimeError('gl error %s' % (status,))
def renderScene(programObj, width, height):
"""renderScene - the OpenGL commands to render our scene."""
gl.glMatrixMode(gl.GL_PROJECTION)
gl.glLoadIdentity()
glu.gluOrtho2D(0, width, 0, height)
gl.glViewport(0, 0, width, height)
gl.glMatrixMode(gl.GL_MODELVIEW)
gl.glLoadIdentity()
gl.glUseProgram(programObj)
# Draw one texture mapped quad in the (x,y) plane
gl.glBegin(gl.GL_QUADS)
gl.glTexCoord2f(0., 0.)
gl.glVertex2f(0., 0.)
gl.glTexCoord2f(1., 0.)
gl.glVertex2f(float(width), 0.)
gl.glTexCoord2f(1., 1.)
gl.glVertex2f(float(width), float(height))
gl.glTexCoord2f(0., 1.)
gl.glVertex2f(0., float(height))
gl.glEnd()
gl.glUseProgram(0)
checkGLError()
useShaders = True
glfw.glfwInit()
window = glfw.glfwCreateWindow(512, 512)
glfw.glfwShowWindow(window)
glfw.glfwMakeContextCurrent(window)
time.sleep(400e-3) # needed on Linux for window to show up
# Load one texture with the original image
# and create two textures of the same size for the iterative rendering
gl.glEnable(gl.GL_TEXTURE_2D)
gl.glActiveTexture(gl.GL_TEXTURE0)
textureID = gl.glGenTextures(3)
texw, texh = loadShapeTexture("shape1.tga", textureID[0])
createBufferTexture(textureID[1], texw, texh)
createBufferTexture(textureID[2], texw, texh)
fboID = gl.glGenFramebuffers(1)
programObj0 = createShader("vertex.glsl", "fragment_seed.glsl")
programObj1 = createShader("vertex.glsl", "fragment_flood.glsl")
programObj2 = createShader("vertex.glsl", "fragment_display.glsl")
glfw.glfwSwapInterval(0)
running = True
while running:
showFPS(texw, texh)
if not useShaders:
gl.glBindTexture(gl.GL_TEXTURE_2D, textureID[0]) # Pass-through
else:
setUniformVariables(programObj0, 0, texw, texh, 0)
gl.glBindTexture(gl.GL_TEXTURE_2D, textureID[0])
gl.glBindFramebuffer(gl.GL_DRAW_FRAMEBUFFER, fboID)
lastRendered = 1
gl.glFramebufferTexture2D(gl.GL_DRAW_FRAMEBUFFER,
gl.GL_COLOR_ATTACHMENT0,
gl.GL_TEXTURE_2D,
textureID[lastRendered], 0)
renderScene(programObj0, texw, texh)
stepsize = texw//2 if texw > texh else texh//2
while stepsize > 0:
setUniformVariables(programObj1, 0, texw, texh, stepsize)
gl.glBindTexture(gl.GL_TEXTURE_2D, textureID[lastRendered])
lastRendered = 1 if lastRendered == 2 else 2
gl.glFramebufferTexture2D(gl.GL_DRAW_FRAMEBUFFER,
gl.GL_COLOR_ATTACHMENT0,
gl.GL_TEXTURE_2D,
textureID[lastRendered], 0)
renderScene(programObj1, texw, texh)
stepsize = stepsize // 2
gl.glBindFramebuffer(gl.GL_DRAW_FRAMEBUFFER, 0)
gl.glBindTexture(gl.GL_TEXTURE_2D, textureID[lastRendered])
width, height = glfw.glfwGetWindowSize(window)
height = max(height, 1)
width = max(width, 1)
setUniformVariables(programObj2, 0, texw, texh, 0)
renderScene(programObj2, width, height)
glfw.glfwSwapBuffers(window)
glfw.glfwPollEvents()
if glfw.glfwGetKey(window, glfw.GLFW_KEY_1) == glfw.GLFW_PRESS:
texw, texh = loadShapeTexture("shape1.tga", textureID[0])
createBufferTexture(textureID[1], texw, texh)
createBufferTexture(textureID[2], texw, texh)
if glfw.glfwGetKey(window, glfw.GLFW_KEY_2):
texw, texh = loadShapeTexture("shape2.tga", textureID[0])
createBufferTexture(textureID[1], texw, texh)
createBufferTexture(textureID[2], texw, texh)
if glfw.glfwGetKey(window, glfw.GLFW_KEY_3):
texw, texh = loadShapeTexture("shape3.tga", textureID[0])
createBufferTexture(textureID[1], texw, texh)
createBufferTexture(textureID[2], texw, texh)
if glfw.glfwGetKey(window, glfw.GLFW_KEY_4):
texw, texh = loadShapeTexture("shape4.tga", textureID[0])
createBufferTexture(textureID[1], texw, texh)
createBufferTexture(textureID[2], texw, texh)
if glfw.glfwGetKey(window, glfw.GLFW_KEY_F1):
useShaders = True
if glfw.glfwGetKey(window, glfw.GLFW_KEY_F2):
useShaders = False
# Check if the ESC key is pressed or the window has been closed
running = not glfw.glfwGetKey(window, glfw.GLFW_KEY_ESCAPE)
glfw.glfwTerminate()
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