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Implement separate class for rendering Skew-T legends

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XANTRONIX 2025-02-24 11:28:35 -05:00
parent eaa23d4b41
commit dcf2f2034c
1 changed files with 59 additions and 1 deletions
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60
lib/xmet/skew_t.py
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@ -13,7 +13,7 @@ PRESSURE_LOG_MAX = math.log(PRESSURE_MAX)
PRESSURE_LOG_MIN = math.log(PRESSURE_MIN)
PRESSURE_LOG_RANGE = PRESSURE_LOG_MAX - PRESSURE_LOG_MIN
TEMP_MAX = 50
TEMP_MAX = 50 # degrees C
TEMP_MIN = -50
TEMP_RANGE = TEMP_MAX - TEMP_MIN
TEMP_CENTER = 0 # degrees C
@ -131,3 +131,61 @@ class SkewTGraph():
self.draw_samples(cr, x, y, samples, lambda s: s.dewpoint)
cr.reset_clip()
class SkewTLegend():
@staticmethod
def draw_isotherm_legends_for_graph(cr: cairo.Context,
skew_t: SkewTGraph,
x: float,
y: float):
temp = TEMP_MAX
while True:
text = "%d°C" % (temp)
extents = cr.text_extents(text)
x_rel, y_rel = skew_t.sample_to_screen(temp, PRESSURE_MAX)
if x_rel < 0:
y_rel = skew_t.height + x_rel
x_rel = 0
if y_rel <= 0:
break
cr.move_to(x + x_rel - extents.width - 8,
y + y_rel + extents.height / 2)
else:
cr.move_to(x + x_rel - extents.width / 2,
y + y_rel + extents.height + 8)
cr.show_text(text)
cr.stroke()
temp -= 2 * TEMP_STEP
@staticmethod
def draw_isobar_legends_for_graph(cr: cairo.Context,
skew_t: SkewTGraph,
x: float,
y: float):
for pressure in range(PRESSURE_MAX, PRESSURE_MIN-1, -2*PRESSURE_STEP):
x_rel = skew_t.width
y_rel = skew_t.height - skew_t.pressure_to_y(pressure)
text = "%dmb" % (pressure)
extents = cr.text_extents(text)
cr.move_to(x + x_rel + 8,
y + y_rel + extents.height / 2)
cr.show_text(text)
cr.stroke()
@staticmethod
def draw_for_graph(cr: cairo.Context,
skew_t: SkewTGraph,
x: float,
y: float):
SkewTLegend.draw_isotherm_legends_for_graph(cr, skew_t, x, y)
SkewTLegend.draw_isobar_legends_for_graph(cr, skew_t, x, y)