Merge pull request #1915 from midichef/graph_y

[graph] fix top margin location and simplify y-coordinate calculation

visidata/canvas.py

@@ -388,13 +388,10 @@ def statusLine(self):
 
  @property
  def canvasMouse(self):
- return self.canvasFromPlotterCoord(self.plotterMouse.x, self.plotterMouse.y)
-
- def canvasFromPlotterCoord(self, plotter_x, plotter_y):
- return Point(self.visibleBox.xmin + (plotter_x-self.plotviewBox.xmin)/self.xScaler, self.visibleBox.ymin + (plotter_y-self.plotviewBox.ymin)/self.yScaler)
-
- def canvasFromTerminalCoord(self, x, y):
- return self.canvasFromPlotterCoord(*self.plotterFromTerminalCoord(x, y))
+ x = self.plotterMouse.x
+ y = self.plotterMouse.y
+ p = Point(self.unscaleX(x), self.unscaleY(y))
+ return p
 
  def setCursorSize(self, p):
  'sets width based on diagonal corner p'
@@ -446,6 +443,9 @@ def plotterCursorBox(self):
  self.scaleX(self.cursorBox.xmax),
  self.scaleY(self.cursorBox.ymax))
 
+ def startCursor(self):
+ self.cursorBox = Box(*self.canvasMouse.xy)
+
  def point(self, x, y, attr=0, row=None):
  self.polylines.append(([(x, y)], attr, row))
 
@@ -606,14 +606,21 @@ def calcVisibleBoxHeight(self):
  else:
  return h
 
- #could be called canvas_to_plotterX()
- def scaleX(self, x):
- 'returns plotter x coordinate'
- return round(self.plotviewBox.xmin+(x-self.visibleBox.xmin)*self.xScaler)
+ def scaleX(self, canvasX):
+ 'returns a plotter x coordinate'
+ return round(self.plotviewBox.xmin+(canvasX-self.visibleBox.xmin)*self.xScaler)
+
+ def scaleY(self, canvasY):
+ 'returns a plotter y coordinate'
+ return round(self.plotviewBox.ymin+(canvasY-self.visibleBox.ymin)*self.yScaler)
 
- def scaleY(self, y):
- 'returns plotter y coordinate'
- return round(self.plotviewBox.ymin+(y-self.visibleBox.ymin)*self.yScaler)
+ def unscaleX(self, plotterX):
+ 'performs the inverse of scaleX, returns a canvas x coordinate'
+ return (plotterX-self.plotviewBox.xmin)/self.xScaler + self.visibleBox.xmin
+
+ def unscaleY(self, plotterY):
+ 'performs the inverse of scaleY, returns a canvas y coordinate'
+ return (plotterY-self.plotviewBox.ymin)/self.yScaler + self.visibleBox.ymin
 
  def canvasW(self, plotter_width):
  'plotter X units to canvas units'
@@ -637,25 +644,33 @@ def render(self, h, w):
 
  @asyncthread
  def render_async(self):
- self.render_sync()
+ self.plot_elements()
 
- def render_sync(self):
- 'plots points and lines and text onto the Plotter'
+ def plot_elements(self, invert_y=False):
+ 'plots points and lines and text onto the plotter'
 
  self.resetBounds()
 
  bb = self.visibleBox
  xmin, ymin, xmax, ymax = bb.xmin, bb.ymin, bb.xmax, bb.ymax
  xfactor, yfactor = self.xScaler, self.yScaler
- plotxmin, plotymin = self.plotviewBox.xmin, self.plotviewBox.ymin
+ plotxmin = self.plotviewBox.xmin
+ if invert_y:
+ plotymax = self.plotviewBox.ymax
+ else:
+ plotymin = self.plotviewBox.ymin
 
  for vertexes, attr, row in Progress(self.polylines, 'rendering'):
  if len(vertexes) == 1: # single point
  x1, y1 = vertexes[0]
  x1, y1 = float(x1), float(y1)
  if xmin <= x1 <= xmax and ymin <= y1 <= ymax:
+ # equivalent to self.scaleX(x1) and self.scaleY(y1), inlined for speed
  x = plotxmin+(x1-xmin)*xfactor
- y = plotymin+(y1-ymin)*yfactor
+ if invert_y:
+ y = plotymax-(y1-ymin)*yfactor
+ else:
+ y = plotymin+(y1-ymin)*yfactor
  self.plotpixel(round(x), round(y), attr, row)
  continue
 
@@ -665,9 +680,13 @@ def render_sync(self):
  if r:
  x1, y1, x2, y2 = r
  x1 = plotxmin+float(x1-xmin)*xfactor
- y1 = plotymin+float(y1-ymin)*yfactor
  x2 = plotxmin+float(x2-xmin)*xfactor
- y2 = plotymin+float(y2-ymin)*yfactor
+ if invert_y:
+ y1 = plotymax-float(y1-ymin)*yfactor
+ y2 = plotymax-float(y2-ymin)*yfactor
+ else:
+ y1 = plotymin+float(y1-ymin)*yfactor
+ y2 = plotymin+float(y2-ymin)*yfactor
  self.plotline(x1, y1, x2, y2, attr, row)
  prev_x, prev_y = x, y
 
@@ -718,7 +737,7 @@ def deleteSourceRows(self, rows):
 Canvas.addCommand('z_', 'set-aspect', 'sheet.aspectRatio = float(input("aspect ratio=", value=aspectRatio)); refresh()', 'set aspect ratio')
 
 # set cursor box with left click
-Canvas.addCommand('BUTTON1_PRESSED', 'start-cursor', 'sheet.cursorBox = Box(*canvasMouse.xy)', 'start cursor box with left mouse button press')
+Canvas.addCommand('BUTTON1_PRESSED', 'start-cursor', 'startCursor()', 'start cursor box with left mouse button press')
 Canvas.addCommand('BUTTON1_RELEASED', 'end-cursor', 'setCursorSize(canvasMouse)', 'end cursor box with left mouse button release')
 
 Canvas.addCommand('BUTTON3_PRESSED', 'start-move', 'sheet.anchorPoint = canvasMouse', 'mark grid point to move')

visidata/graph.py

@@ -10,37 +10,44 @@ def numericCols(vd, cols):
 
 
 class InvertedCanvas(Canvas):
+ @asyncthread
+ def render_async(self):
+ self.plot_elements(invert_y=True)
+
  def zoomTo(self, bbox):
  super().zoomTo(bbox)
- self.fixPoint(Point(self.plotviewBox.xmin, self.plotviewBox.ymax), bbox.xymin)
-
- def plotpixel(self, x, y, attr, row=None):
- y = self.plotviewBox.ymax-y
- self.pixels[y][x][attr].append(row)
+ self.fixPoint(Point(self.plotviewBox.xmin, self.plotviewBox.ymax),
+ Point(bbox.xmin, bbox.ymax + 1/4*self.canvasCharHeight))
 
  def scaleY(self, canvasY):
- 'returns plotter y coordinate, with y-axis inverted'
- plotterY = super().scaleY(canvasY)
- return (self.plotviewBox.ymax-plotterY+4)
+ 'returns a plotter y coordinate for a canvas y coordinate, with the y direction inverted'
+ return self.plotviewBox.ymax-round((canvasY-self.visibleBox.ymin)*self.yScaler)
 
- def canvasH(self, plotterY):
- return (self.plotviewBox.ymax-plotterY)/self.yScaler
+ def unscaleY(self, plotterY_inverted):
+ 'performs the inverse of scaleY, returns a canvas y coordinate'
+ return (self.plotviewBox.ymax-plotterY_inverted)/self.yScaler + self.visibleBox.ymin
 
  @property
  def canvasMouse(self):
  p = super().canvasMouse
- p.y = self.visibleBox.ymin + (self.plotviewBox.ymax-self.plotterMouse.y)/self.yScaler
+ p.y = self.unscaleY(self.plotterMouse.y)
  return p
 
  def calcTopCursorY(self):
  'ymin for the cursor that will align its top with the top edge of the graph'
- return self.visibleBox.ymax + self.canvasCharHeight - self.cursorBox.h
+ return self.visibleBox.ymax - self.cursorBox.h
 
  def calcBottomCursorY(self):
- 'ymin for the cursor that will align its bottom with the bottom edge of the graph'
  # Shift by 1 plotter pixel, like with goTopCursorY for Canvas. But shift in the
  # opposite direction, because the y-coordinate system is inverted.
- return self.visibleBox.ymin + self.canvasCharHeight - (1/4 * self.canvasCharHeight) 
+ 'ymin for the cursor that will align its bottom with the bottom edge of the graph'
+ return self.visibleBox.ymin - (1/4 * self.canvasCharHeight)
+
+ def startCursor(self):
+ super().startCursor()
+ # Since the y coordinates for plotting increase in the opposite
+ # direction from Canvas, the cursor has to be shifted.
+ self.cursorBox.ymin -= self.canvasCharHeight
 
 # provides axis labels, legend
 class GraphSheet(InvertedCanvas):