moving to Cairo instead of svgwrite

apple410/__init__.py

@@ -44,6 +44,8 @@ class Apple410(Apple410Common):
             self.serial.flush()
         else:
             self.serial.flush()
+            while not self.serial.cts:
+                time.sleep(0.2)
             while not self.serial.dsr:
                 time.sleep(0.2)
             self.serial.write(c.encode('ascii'))

apple410/plot_to_cairo.py

@@ -0,0 +1,158 @@
+#!/usr/bin/python3
+import sys
+import math
+import cairo
+
+def coordlist(line,expected=-1):
+    l = list(map(float,line.split(',')))
+    if expected > -1:
+        assert len(l) == expected
+    return l
+
+#pens = [
+#    svgwrite.rgb(0, 0, 0, '%'),
+#    svgwrite.rgb(100, 0, 0, '%'),
+#    svgwrite.rgb(0, 100, 0, '%'),
+#    svgwrite.rgb(0, 0, 100, '%') ]
+
+# Default W/H
+W = 2394
+H = 1759
+LW = 5
+
+class CairoPlotter:
+
+    def __init__(self, path):
+        self.surface = cairo.SVGSurface(path, W, H)
+        self.context = cairo.Context(self.surface)
+        #self.context.scale(W,H)
+        self.context.select_font_face("monospace")
+        self.pennum = 0
+        self.viewport = (0, 0, W, H)
+        self.window = (0, 0, W, H)
+        self.text_theta = 0
+        self.text_size = 1
+        #self.pos = (0,0)
+        #self.clip = None
+        #self.clipno = 0
+        self.in_path = False
+        self.update_ctm()
+        self.context.set_line_width(LW)
+
+    # A quick review of coordinate systems:
+    # Cairo native: origin at upper left, x+ to right, y+ down.
+    # Plotter native: origin at lower left, x+ to right, y+ up.
+    # Plotter window: same as plotter native.
+    # We want to display in plotter native.
+    def update_ctm(self):
+        pn_to_cn = cairo.Matrix(yy=-1.0, y0=H)
+        self.context.set_matrix(pn_to_cn)
+
+    def update_font(self):
+        m = cairo.Matrix(xx=self.text_size, yy=-self.text_size)
+        m2 = cairo.Matrix.init_rotate(math.radians(self.text_theta))
+        m.multiply(m2)
+        self.context.set_font_matrix(m)
+
+    def finish_path(self):
+        if self.in_path:
+            self.context.stroke_preserve()
+            self.in_path = False
+
+    def invalidate_window(self):
+        pass
+
+    def vp(self, params):
+        self.invalidate_window()
+        l=coordlist(params,4)
+        self.viewport=(l[0],l[1],l[2],l[3])
+
+    def wd(self, params):
+        self.invalidate_window()
+        l=coordlist(params,4)
+        self.window=(l[0],l[1],l[2],l[3])
+    
+    def ma(self, params):
+        l=coordlist(params,2)
+        self.context.move_to(l[0],l[1])
+
+    def mr(self, params):
+        l=coordlist(params,2)
+        p=self.context.get_current_point()
+        self.context.move_to(p[0]+l[0],p[1]+l[1])
+
+    def da(self, params):
+        l=coordlist(params)
+        self.in_path = True
+        while len(l) > 0:
+            x, y, l = l[0],l[1],l[2:]
+            self.context.line_to(x,y)
+
+    def dr(self, params):
+        l=coordlist(params)
+        self.in_path = True
+        while len(l) > 0:
+            x, y, l = l[0],l[1],l[2:]
+            p=self.context.get_current_point()
+            self.context.line_to(p[0]+x,p[1]+y)
+
+    def ca(self, params):
+        self.context.new_sub_path()
+        l=coordlist(params)
+        r=l[0]
+        if len(l) > 2:
+            p=(l[1],l[2])
+        else:
+            p=self.context.get_current_point()
+        self.context.arc(p[0],p[1],r,0.0,math.pi*2)
+
+    def ac(self,params):
+        l=coordlist(params)
+        r=l[0]
+        if len(l) > 3:
+            p=(l[3],l[4])
+        else:
+            p=self.pos
+        t2, t1 = math.radians(l[1]),math.radians(l[2])
+        self.context.arc(p[0],p[1],r,t1,t2)
+
+    def lr(self,params):
+        self.text_theta = float(params)
+        self.update_font()
+
+    def ls(self,params):
+        self.text_size = float(params)
+        self.update_font()
+
+    def ps(self,params):
+        self.finish_path()
+        self.pennum = int(params) - 1
+
+    def pl(self,params):
+        self.finish_path()
+        (x,y) = self.context.get_current_point()
+        sys.stderr.write("text at {} {}\n".format(x,y))
+        self.context.show_text(params)
+
+    def write(self,out):
+        self.finish_path()
+        self.surface.finish()
+
+    def process_cmd(self,command):
+        cmd_code = command[0:2].lower()
+        params = command[2:]
+        try:
+            getattr(self,cmd_code)(params)
+        except AttributeError:
+            sys.stderr.write("Unrecognized command code {}\n".format(cmd_code))
+
+    def read(self,inf):
+        for line in inf.readlines():
+            line = line.strip()
+            self.process_cmd(line)
+
+if __name__=='__main__':
+    p = CairoPlotter('foo.svg')
+    p.read(sys.stdin)
+    p.write(sys.stdout)
+