本文整理汇总了Python中qgis.core.QgsRenderContext.setMapToPixel方法的典型用法代码示例。如果您正苦于以下问题：Python QgsRenderContext.setMapToPixel方法的具体用法？Python QgsRenderContext.setMapToPixel怎么用？Python QgsRenderContext.setMapToPixel使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类qgis.core.QgsRenderContext的用法示例。
在下文中一共展示了QgsRenderContext.setMapToPixel方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: isFeatureRendered
# 需要导入模块: from qgis.core import QgsRenderContext [as 别名]
# 或者: from qgis.core.QgsRenderContext import setMapToPixel [as 别名]
def isFeatureRendered(canvas, layer, feature):
renderer = layer.rendererV2()
renderContext = QgsRenderContext()
renderContext.setExtent(canvas.mapRenderer().rendererContext().extent())
renderContext.setMapToPixel(canvas.mapRenderer().rendererContext().mapToPixel())
renderContext.setRendererScale(canvas.mapRenderer().scale())
if QGis.QGIS_VERSION_INT >= 20300:
renderer.startRender(renderContext, layer.pendingFields())
else:
renderer.startRender(renderContext, layer)
ans = renderer.willRenderFeature(feature)
renderer.stopRender(renderContext)
return ans示例2: identify
# 需要导入模块: from qgis.core import QgsRenderContext [as 别名]
# 或者: from qgis.core.QgsRenderContext import setMapToPixel [as 别名]
def identify(self, params):
self.check_required_params(params)
feature_collections = []
with change_directory(self.project_root):
crs = QgsCoordinateReferenceSystem()
crs.createFromSrid(params.get('srs'))
search_box = self._calcSearchBox(
params.get('bbox'), params.get('image_size')[0],
params.get('image_size')[1],
params.get('click_point')[0], params.get('click_point')[1]
)
# initialize mapRenderer and a rendering context in order to be
# to check if a feature will actually be rendered
# we don't want to return features that are not visible
img = QImage(QSize(
settings.SUNLUMO_GFI_BUFFER*2, settings.SUNLUMO_GFI_BUFFER*2),
QImage.Format_ARGB32_Premultiplied
)
dpm = 1 / 0.00028
img.setDotsPerMeterX(dpm)
img.setDotsPerMeterY(dpm)
mapRenderer = QgsMapRenderer()
mapRenderer.clearLayerCoordinateTransforms()
mapRenderer.setOutputSize(QSize(
settings.SUNLUMO_GFI_BUFFER*2, settings.SUNLUMO_GFI_BUFFER*2),
img.logicalDpiX()
)
mapRenderer.setDestinationCrs(crs)
mapRenderer.setProjectionsEnabled(True)
mapUnits = crs.mapUnits()
mapRenderer.setMapUnits(mapUnits)
mapExtent = QgsRectangle(*search_box)
mapRenderer.setExtent(mapExtent)
renderContext = QgsRenderContext()
renderContext.setExtent(mapRenderer.extent())
renderContext.setRasterScaleFactor(1.0)
renderContext.setMapToPixel(mapRenderer.coordinateTransform())
renderContext.setRendererScale(mapRenderer.scale())
renderContext.setScaleFactor(mapRenderer.outputDpi() / 25.4)
renderContext.setPainter(None)
qfr = QgsFeatureRequest()
search_rectangle = QgsRectangle(*search_box)
qfr.setFilterRect(search_rectangle)
for q_layer in params.get('query_layers'):
layer = self.layerRegistry.mapLayer(q_layer)
if layer.type() == QgsMapLayer.RasterLayer:
# skip raster layer processing
continue
# update layer fields (expressions, calculated, joined)
layer.updateFields()
scaleCalc = QgsScaleCalculator(
(img.logicalDpiX() + img.logicalDpiY()) / 2,
mapRenderer.destinationCrs().mapUnits()
)
scaleDenom = scaleCalc.calculate(mapExtent, img.width())
# skip the layer if it's not visible at the current map scale
if layer.hasScaleBasedVisibility():
if not(layer.minimumScale()
< scaleDenom < layer.maximumScale()):
continue
# check if features actually intersect search rectangle
intersected_features = self._intersectedFeatures(
layer.getFeatures(qfr), search_rectangle
)
# visible features generator
visible_features = self._visibleFeatures(
layer, renderContext, intersected_features
)
layer_features = [featureToGeoJSON(
feature.id(), feature.geometry(),
self._collectAttributes(layer, feature)
) for feature in visible_features
]
feature_collections.append(layer_features)
return writeGeoJSON(chain(*feature_collections))