cylinder drawing

cylinder_drawing_example.py

@@ -0,0 +1,59 @@
+import cairocffi as cairo
+import math
+
+
+def draw_cylinders(width, height, filename):
+    # Setup surface and context
+    surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
+    ctx = cairo.Context(surface)
+
+    # White background
+    ctx.set_source_rgb(1, 1, 1)
+    ctx.paint()
+
+    # Cylinder dimensions
+    cyl_width = 80
+    cyl_height = 200
+    top_ellipse_height = 30
+    spacing = 50
+
+    # Starting position
+    start_x = 50
+    y = 50
+
+    for i in range(3):
+        x = start_x + i * (cyl_width + spacing)
+
+        # 1. Draw Side Gradient (Rect + Arc)
+        # Create a vertical linear gradient: White (top) to Blue (bottom)
+        pat = cairo.LinearGradient(x, y, x+cyl_width, y)
+        pat.add_color_stop_rgb(0, 1, 1, 1)  # White top
+        pat.add_color_stop_rgb(1, 0.2, 0.2, 1)  # Blue bottom
+
+        # Draw the rectangle body
+        ctx.rectangle(x, y + top_ellipse_height / 2, cyl_width, cyl_height - top_ellipse_height / 2)
+        ctx.set_source(pat)
+        ctx.fill()
+
+        # 2. Draw Top Ellipse (White)
+        ctx.save()
+        ctx.translate(x + cyl_width / 2, y + top_ellipse_height / 2)
+        ctx.scale(1, top_ellipse_height / (cyl_width / 2) * 0.5)  # Ellipse scale
+        ctx.arc(0, 0, cyl_width / 2, 0, 2 * math.pi)
+        ctx.restore()
+
+        ctx.set_source_rgb(1, 1, 1)  # White
+        ctx.fill_preserve()
+
+        # Outline for better visibility
+        ctx.set_source_rgb(0, 0, 0)
+        ctx.set_line_width(1)
+        ctx.stroke()
+
+    # Save to PNG
+    surface.write_to_png(filename)
+    print(f"Saved {filename}")
+
+
+if __name__ == "__main__":
+    draw_cylinders(450, 300, "cylinders.png")

topologytool.py

@@ -10,6 +10,7 @@ import ee
 import numpy as np
 import pandas as pd
 import cairocffi as cairo
+import math
 
 class Topology:
     def __init__(self,
@@ -161,26 +162,22 @@ class Topology:
                     values[r, c] = np.mean(this_array[this_array != 0])
         return values
 
-    def create_rectangle_svg_file(self, rotation=None,file_index=None):
+    def create_cylinder_svg_file(self, rotation=None,file_index=None):
 
         # subfunction to draw an array, options are line y/n, fill y/n, line and fill color
-        def svg_draw_list(svg_context, draw_list, line_color="White",fill_shape=False):
-            if line_color == "White":
-                svg_context.set_source_rgb(1, 1, 1)
-            if line_color == "Black":
-                svg_context.set_source_rgb(0, 0, 0)
-
-            for item in range(len(draw_list)):
-                if item == 0:
-                    svg_context.move_to(draw_list[item][0],draw_list[item][1])
-                else:
-                    svg_context.line_to(draw_list[item][0],draw_list[item][1])
-            if fill_shape:
-                svg_context.close_path()
-                svg_context.fill_preserve()
+        def svg_draw_cylinder(svg_context: cairo.Context, x1,y1,x2,y2,gradient=None):
+            circlew = self.linemap_xscale / 3
+            halfcirclew = circlew / 2
+            svg_context.set_source_rgb(1, 1, 1)
+            svg_context.arc(x1,y1,circlew,0,2*math.pi)
             svg_context.stroke()
 
+            svg_context.arc(x2,y2,circlew, 0,2*math.pi)
+            svg_context.stroke()
 
+            svg_context.move_to(x1-1,y1-1)
+            svg_context.rectangle(x1-1,y1-1,x1+1,y2+1)
+            svg_context.stroke()
         # if no refetch, check if file exists
         if os.path.exists(self.elevation_filename):
             print("Elevation file exists")
@@ -247,9 +244,9 @@ class Topology:
                     z = norm_data[r,c]
                     x,y = project(c, r, z) # now need to make array of x,y vals and pass to drawing func
                     draw_list.append((x,y))
+                    svg_draw_cylinder(cr,x,y,x,y-z)
                 print("***" + str(draw_list))
-                svg_draw_list(cr, draw_list, line_color="Black", fill_shape=True)
-                svg_draw_list(cr, draw_list, line_color="White", fill_shape=False)
+                #svg_draw_list(cr, draw_list, line_color="Black", fill_shape=True)
 
 
         surface.write_to_png(svg_filename.replace(".svg", ".topo.png"))
@@ -371,15 +368,16 @@ def main():
     topology = Topology(country="Switzerland",
                         storage_directory="/Users/he/PycharmProjects/toposhirt/outputfiles",
                         subregion_mode=False,
-                        linemap_cols=200,
-                        linemap_rows=200,
+                        linemap_cols=50,
+                        linemap_rows=50,
                         linemap_size=(1080,1080),
                         linemap_width=0.3)
     topology.list_subunits()
     print(topology.get_boundingbox())
-    topology.create_svg_file()
-    for r in range(4*360):
-        print("Rotating by [{}] degrees".format(r/4.0))
+    #topology.create_svg_file()
+    topology.create_cylinder_svg_file()
+    #for r in range(4*360):
+        #print("Rotating by [{}] degrees".format(r/4.0))
         #topology.create_svg_file(rotation=(r / 4.0), file_index=r)
 
     sys.exit(0)