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Diffstat (limited to 'src/silx/gui/plot3d/scene/viewport.py')
| -rw-r--r-- | src/silx/gui/plot3d/scene/viewport.py | 611 |
1 files changed, 611 insertions, 0 deletions
diff --git a/src/silx/gui/plot3d/scene/viewport.py b/src/silx/gui/plot3d/scene/viewport.py new file mode 100644 index 0000000..c39d3ef --- /dev/null +++ b/src/silx/gui/plot3d/scene/viewport.py @@ -0,0 +1,611 @@ +# /*########################################################################## +# +# Copyright (c) 2015-2019 European Synchrotron Radiation Facility +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. +# +# ###########################################################################*/ +"""This module provides a class to control a viewport on the rendering window. + +The :class:`Viewport` describes a Viewport rendering a scene. +The attribute :attr:`scene` is the root group of the scene tree. +:class:`RenderContext` handles the current state during rendering. +""" + +__authors__ = ["T. Vincent"] +__license__ = "MIT" +__date__ = "24/04/2018" + + +import string +import numpy + +from silx.gui.colors import rgba + +from ..._glutils import gl + +from . import camera +from . import event +from . import transform +from .function import DirectionalLight, ClippingPlane, Fog + + +class RenderContext(object): + """Handle a current rendering context. + + An instance of this class is passed to rendering method through + the scene during render. + + User should NEVER use an instance of this class beyond the method + it is passed to as an argument (i.e., do not keep a reference to it). + + :param Viewport viewport: The viewport doing the rendering. + :param Context glContext: The operating system OpenGL context in use. + """ + + _FRAGMENT_SHADER_SRC = string.Template( + """ + void scene_post(vec4 cameraPosition) { + gl_FragColor = $fogCall(gl_FragColor, cameraPosition); + } + """ + ) + + def __init__(self, viewport, glContext): + self._viewport = viewport + self._glContext = glContext + self._transformStack = [viewport.camera.extrinsic] + self._clipPlane = ClippingPlane(normal=(0.0, 0.0, 0.0)) + + # cache + self.__cache = {} + + def cache(self, key, factory, *args, **kwargs): + """Lazy-loading cache to store values in the context for rendering + + :param key: The key to retrieve + :param factory: A callback taking args and kwargs as arguments + and returning the value to store. + :return: The stored or newly allocated value + """ + if key not in self.__cache: + self.__cache[key] = factory(*args, **kwargs) + return self.__cache[key] + + @property + def viewport(self): + """Viewport doing the current rendering""" + return self._viewport + + @property + def glCtx(self): + """The OpenGL context in use""" + return self._glContext + + @property + def objectToCamera(self): + """The current transform from object to camera coords. + + Do not modify. + """ + return self._transformStack[-1] + + @property + def projection(self): + """Projection transform. + + Do not modify. + """ + return self.viewport.camera.intrinsic + + @property + def objectToNDC(self): + """The transform from object to NDC (this includes projection). + + Do not modify. + """ + return transform.StaticTransformList((self.projection, self.objectToCamera)) + + def pushTransform(self, transform_, multiply=True): + """Push a :class:`Transform` on the transform stack. + + :param Transform transform_: The transform to add to the stack. + :param bool multiply: + True (the default) to multiply with the top of the stack, + False to push the transform as is without multiplication. + """ + if multiply: + assert len(self._transformStack) >= 1 + transform_ = transform.StaticTransformList( + (self._transformStack[-1], transform_) + ) + + self._transformStack.append(transform_) + + def popTransform(self): + """Pop the transform on top of the stack. + + :return: The Transform that is popped from the stack. + """ + assert len(self._transformStack) > 1 + return self._transformStack.pop() + + @property + def clipper(self): + """The current clipping plane (ClippingPlane)""" + return self._clipPlane + + def setClipPlane(self, point=(0.0, 0.0, 0.0), normal=(0.0, 0.0, 0.0)): + """Set the clipping plane to use + + For now only handles a single clipping plane. + + :param point: A point of the plane + :type point: 3-tuple of float + :param normal: Normal vector of the plane or (0, 0, 0) for no clipping + :type normal: 3-tuple of float + """ + self._clipPlane = ClippingPlane(point, normal) + + def setupProgram(self, program): + """Sets-up uniforms of a program using the context shader functions. + + :param GLProgram program: The program to set-up. + It MUST be in use and using the context function. + """ + self.clipper.setupProgram(self, program) + self.viewport.fog.setupProgram(self, program) + + @property + def fragDecl(self): + """Fragment shader declaration for scene shader functions""" + return "\n".join( + ( + self.clipper.fragDecl, + self.viewport.fog.fragDecl, + self._FRAGMENT_SHADER_SRC.substitute( + fogCall=self.viewport.fog.fragCall + ), + ) + ) + + @property + def fragCallPre(self): + """Fragment shader call for scene shader functions (to do first) + + It takes the camera position (vec4) as argument. + """ + return self.clipper.fragCall + + @property + def fragCallPost(self): + """Fragment shader call for scene shader functions (to do last) + + It takes the camera position (vec4) as argument. + """ + return "scene_post" + + +class Viewport(event.Notifier): + """Rendering a single scene through a camera in part of a framebuffer. + + :param int framebuffer: The framebuffer ID this viewport is rendering into + """ + + def __init__(self, framebuffer=0): + from . import Group # Here to avoid cyclic import + + super(Viewport, self).__init__() + self._dirty = True + self._origin = 0, 0 + self._size = 1, 1 + self._framebuffer = int(framebuffer) + self.scene = Group() # The stuff to render, add overlaid scenes? + self.scene._setParent(self) + self.scene.addListener(self._changed) + self._background = 0.0, 0.0, 0.0, 1.0 + self._camera = camera.Camera( + fovy=30.0, near=1.0, far=100.0, position=(0.0, 0.0, 12.0) + ) + self._camera.addListener(self._changed) + self._transforms = transform.TransformList([self._camera]) + + self._light = DirectionalLight( + direction=(0.0, 0.0, -1.0), ambient=(0.3, 0.3, 0.3), diffuse=(0.7, 0.7, 0.7) + ) + self._light.addListener(self._changed) + self._fog = Fog() + self._fog.isOn = False + self._fog.addListener(self._changed) + + @property + def transforms(self): + """Proxy of camera transforms. + + Do not modify the list. + """ + return self._transforms + + def _changed(self, *args, **kwargs): + """Callback handling scene updates""" + self._dirty = True + self.notify() + + @property + def dirty(self): + """True if scene is dirty and needs redisplay.""" + return self._dirty + + def resetDirty(self): + """Mark the scene as not being dirty. + + To call after rendering. + """ + self._dirty = False + + @property + def background(self): + """Viewport's background color (4-tuple of float in [0, 1] or None) + + The background color is used to clear to viewport. + If None, the viewport is not cleared + """ + return self._background + + @background.setter + def background(self, color): + if color is not None: + color = rgba(color) + if self._background != color: + self._background = color + self._changed() + + @property + def camera(self): + """The camera used to render the scene.""" + return self._camera + + @property + def light(self): + """The light used to render the scene.""" + return self._light + + @property + def fog(self): + """The fog function used to render the scene""" + return self._fog + + @property + def origin(self): + """Origin (ox, oy) of the viewport in pixels""" + return self._origin + + @origin.setter + def origin(self, origin): + ox, oy = origin + origin = int(ox), int(oy) + if origin != self._origin: + self._origin = origin + self._changed() + + @property + def size(self): + """Size (width, height) of the viewport in pixels""" + return self._size + + @size.setter + def size(self, size): + w, h = size + size = int(w), int(h) + if size != self._size: + self._size = size + + self.camera.intrinsic.size = size + self._changed() + + @property + def shape(self): + """Shape (height, width) of the viewport in pixels. + + This is a convenient wrapper to the inverse of size. + """ + return self._size[1], self._size[0] + + @shape.setter + def shape(self, shape): + self.size = shape[1], shape[0] + + @property + def framebuffer(self): + """The framebuffer ID this viewport is rendering into (int)""" + return self._framebuffer + + @framebuffer.setter + def framebuffer(self, framebuffer): + self._framebuffer = int(framebuffer) + + def render(self, glContext): + """Perform the rendering of the viewport + + :param Context glContext: The context used for rendering""" + # Get a chance to run deferred delete + glContext.cleanGLGarbage() + + # OpenGL set-up: really need to be done once + ox, oy = self.origin + w, h = self.size + gl.glViewport(ox, oy, w, h) + + gl.glEnable(gl.GL_SCISSOR_TEST) + gl.glScissor(ox, oy, w, h) + + gl.glEnable(gl.GL_BLEND) + gl.glBlendFunc(gl.GL_SRC_ALPHA, gl.GL_ONE_MINUS_SRC_ALPHA) + + gl.glEnable(gl.GL_DEPTH_TEST) + gl.glDepthFunc(gl.GL_LEQUAL) + gl.glDepthRange(0.0, 1.0) + + # gl.glEnable(gl.GL_POLYGON_OFFSET_FILL) + # gl.glPolygonOffset(1., 1.) + + gl.glHint(gl.GL_LINE_SMOOTH_HINT, gl.GL_NICEST) + gl.glEnable(gl.GL_LINE_SMOOTH) + + if self.background is None: + gl.glClear(gl.GL_STENCIL_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT) + else: + gl.glClearColor(*self.background) + + # Prepare OpenGL + gl.glClear( + gl.GL_COLOR_BUFFER_BIT + | gl.GL_STENCIL_BUFFER_BIT + | gl.GL_DEPTH_BUFFER_BIT + ) + + ctx = RenderContext(self, glContext) + self.scene.render(ctx) + self.scene.postRender(ctx) + + def adjustCameraDepthExtent(self): + """Update camera depth extent to fit the scene bounds. + + Only near and far planes are updated. + The scene might still not be fully visible + (e.g., if spanning behind the viewpoint with perspective projection). + """ + bounds = self.scene.bounds(transformed=True) + if bounds is None: + bounds = numpy.array( + ((0.0, 0.0, 0.0), (1.0, 1.0, 1.0)), dtype=numpy.float32 + ) + bounds = self.camera.extrinsic.transformBounds(bounds) + + if isinstance(self.camera.intrinsic, transform.Perspective): + # This needs to be reworked + zbounds = -bounds[:, 2] + zextent = max(numpy.fabs(zbounds[0] - zbounds[1]), 0.0001) + near = max(zextent / 1000.0, 0.95 * zbounds[1]) + far = max(near + 0.1, 1.05 * zbounds[0]) + + self.camera.intrinsic.setDepthExtent(near, far) + elif isinstance(self.camera.intrinsic, transform.Orthographic): + # Makes sure z bounds are included + border = max(abs(bounds[:, 2])) + self.camera.intrinsic.setDepthExtent(-border, border) + else: + raise RuntimeError("Unsupported camera", self.camera.intrinsic) + + def resetCamera(self): + """Change camera to have the whole scene in the viewing frustum. + + It updates the camera position and depth extent. + Camera sight direction and up are not affected. + """ + bounds = self.scene.bounds(transformed=True) + if bounds is None: + bounds = numpy.array( + ((0.0, 0.0, 0.0), (1.0, 1.0, 1.0)), dtype=numpy.float32 + ) + self.camera.resetCamera(bounds) + + def orbitCamera(self, direction, angle=1.0): + """Rotate the camera around center of the scene. + + :param str direction: Direction of movement relative to image plane. + In: 'up', 'down', 'left', 'right'. + :param float angle: he angle in degrees of the rotation. + """ + bounds = self.scene.bounds(transformed=True) + if bounds is None: + bounds = numpy.array( + ((0.0, 0.0, 0.0), (1.0, 1.0, 1.0)), dtype=numpy.float32 + ) + center = 0.5 * (bounds[0] + bounds[1]) + self.camera.orbit(direction, center, angle) + + def moveCamera(self, direction, step=0.1): + """Move the camera relative to the image plane. + + :param str direction: Direction relative to image plane. + One of: 'up', 'down', 'left', 'right', + 'forward', 'backward'. + :param float step: The ratio of data to step for each pan. + """ + bounds = self.scene.bounds(transformed=True) + if bounds is None: + bounds = numpy.array( + ((0.0, 0.0, 0.0), (1.0, 1.0, 1.0)), dtype=numpy.float32 + ) + bounds = self.camera.extrinsic.transformBounds(bounds) + center = 0.5 * (bounds[0] + bounds[1]) + ndcCenter = self.camera.intrinsic.transformPoint(center, perspectiveDivide=True) + + step *= 2.0 # NDC has size 2 + + if direction == "up": + ndcCenter[1] -= step + elif direction == "down": + ndcCenter[1] += step + + elif direction == "right": + ndcCenter[0] -= step + elif direction == "left": + ndcCenter[0] += step + + elif direction == "forward": + ndcCenter[2] += step + elif direction == "backward": + ndcCenter[2] -= step + + else: + raise ValueError("Unsupported direction: %s" % direction) + + newCenter = self.camera.intrinsic.transformPoint( + ndcCenter, direct=False, perspectiveDivide=True + ) + + self.camera.move(direction, numpy.linalg.norm(newCenter - center)) + + def windowToNdc(self, winX, winY, checkInside=True): + """Convert position from window to normalized device coordinates. + + If window coordinates are int, they are moved half a pixel + to be positioned at the center of pixel. + + :param winX: X window coord, origin left. + :param winY: Y window coord, origin top. + :param bool checkInside: If True, returns None if position is + outside viewport. + :return: (x, y) Normalize device coordinates in [-1, 1] or None. + Origin center, x to the right, y goes upward. + """ + ox, oy = self._origin + width, height = self.size + + # If int, move it to the center of pixel + if isinstance(winX, int): + winX += 0.5 + if isinstance(winY, int): + winY += 0.5 + + x, y = winX - ox, winY - oy + + if checkInside and (x < 0.0 or x > width or y < 0.0 or y > height): + return None # Out of viewport + + ndcx = 2.0 * x / float(width) - 1.0 + ndcy = 1.0 - 2.0 * y / float(height) + return ndcx, ndcy + + def ndcToWindow(self, ndcX, ndcY, checkInside=True): + """Convert position from normalized device coordinates (NDC) to window. + + :param float ndcX: X NDC coord. + :param float ndcY: Y NDC coord. + :param bool checkInside: If True, returns None if position is + outside viewport. + :return: (x, y) window coordinates or None. + Origin top-left, x to the right, y goes downward. + """ + if checkInside and (ndcX < -1.0 or ndcX > 1.0 or ndcY < -1.0 or ndcY > 1.0): + return None # Outside viewport + + ox, oy = self._origin + width, height = self.size + + winx = ox + width * 0.5 * (ndcX + 1.0) + winy = oy + height * 0.5 * (1.0 - ndcY) + return winx, winy + + def _pickNdcZGL(self, x, y, offset=0): + """Retrieve depth from depth buffer and return corresponding NDC Z. + + :param int x: In pixels in window coordinates, origin left. + :param int y: In pixels in window coordinates, origin top. + :param int offset: Number of pixels to look at around the given pixel + + :return: Normalize device Z coordinate of depth in [-1, 1] + or None if outside viewport. + :rtype: float or None + """ + ox, oy = self._origin + width, height = self.size + + x = int(x) + y = height - int(y) # Invert y coord + + if x < ox or x > ox + width or y < oy or y > oy + height: + # Outside viewport + return None + + # Get depth from depth buffer in [0., 1.] + # Bind used framebuffer to get depth + gl.glBindFramebuffer(gl.GL_FRAMEBUFFER, self.framebuffer) + + if offset == 0: # Fast path + # glReadPixels is not GL|ES friendly + depthPatch = gl.glReadPixels(x, y, 1, 1, gl.GL_DEPTH_COMPONENT, gl.GL_FLOAT) + depth = numpy.ravel(depthPatch)[0] + else: + offset = abs(int(offset)) + size = 2 * offset + 1 + depthPatch = gl.glReadPixels( + x - offset, y - offset, size, size, gl.GL_DEPTH_COMPONENT, gl.GL_FLOAT + ) + depthPatch = depthPatch.ravel() # Work in 1D + + # TODO cache sortedIndices to avoid computing it each time + # Compute distance of each pixels to the center of the patch + offsetToCenter = numpy.arange(-offset, offset + 1, dtype=numpy.float32) ** 2 + sqDistToCenter = numpy.add.outer(offsetToCenter, offsetToCenter) + + # Use distance to center to sort values from the patch + sortedIndices = numpy.argsort(sqDistToCenter.ravel()) + sortedValues = depthPatch[sortedIndices] + + # Take first depth that is not 1 in the sorted values + hits = sortedValues[sortedValues != 1.0] + depth = 1.0 if len(hits) == 0 else hits[0] + + gl.glBindFramebuffer(gl.GL_FRAMEBUFFER, 0) + + # Z in NDC in [-1., 1.] + return float(depth) * 2.0 - 1.0 + + def _getXZYGL(self, x, y): + ndc = self.windowToNdc(x, y) + if ndc is None: + return None # Outside viewport + ndcz = self._pickNdcZGL(x, y) + ndcpos = numpy.array((ndc[0], ndc[1], ndcz, 1.0), dtype=numpy.float32) + + camerapos = self.camera.intrinsic.transformPoint( + ndcpos, direct=False, perspectiveDivide=True + ) + + scenepos = self.camera.extrinsic.transformPoint(camerapos, direct=False) + return scenepos[:3] + + def pick(self, x, y): + pass + # ndcX, ndcY = self.windowToNdc(x, y) + # ndcNearPt = ndcX, ndcY, -1. + # ndcFarPT = ndcX, ndcY, 1. |