More work on gradients

lib/squib/card.rb

@@ -1,5 +1,6 @@
 require 'cairo'
 require 'squib/input_helpers'
+require 'squib/graphics/cairo_context_wrapper'
 
 module Squib
   # Back end graphics. Private.
@@ -19,7 +20,7 @@ class Card
     def initialize(deck, width, height)
       @deck=deck; @width=width; @height=height
       @cairo_surface = Cairo::ImageSurface.new(width,height)
-      @cairo_context = Cairo::Context.new(@cairo_surface)
+      @cairo_context = Squib::Graphics::CairoContextWrapper.new(Cairo::Context.new(@cairo_surface))
     end
 
   # A save/restore wrapper for using Cairo

lib/squib/graphics/background.rb

@@ -5,7 +5,7 @@ class Card
     # @api private
     def background(color)
       use_cairo do |cc|
-        cc.set_source_color(color)
+        cc.set_source_squibcolor(color)
         cc.paint
       end
     end

lib/squib/graphics/cairo_context_wrapper.rb

@@ -0,0 +1,42 @@
+require 'forwardable'
+require 'squib/graphics/gradient_regex'
+
+module Squib
+  module Graphics
+    class CairoContextWrapper
+      extend Forwardable
+      attr_accessor :cairo_cxt
+
+      def initialize(cairo_cxt)
+        @cairo_cxt = cairo_cxt
+      end
+
+      def_delegators :cairo_cxt, :save, :set_source_color, :paint, :restore,
+        :translate, :rotate, :move_to, :update_pango_layout, :width, :height,
+        :show_pango_layout, :rounded_rectangle, :set_line_width, :stroke, :fill,
+        :set_source, :scale, :render_rsvg_handle, :circle, :triangle, :line_to,
+        :operator=, :show_page, :clip, :transform, :mask, :create_pango_layout
+
+      def set_source_squibcolor(arg)
+        if match = arg.match(LINEAR_GRADIENT)
+          x1, y1, x2, y2 = match.captures
+          linear = Cairo::LinearPattern.new(x1.to_f, y1.to_f, x2.to_f, y2.to_f)
+          arg.scan(STOPS).each do |color, offset|
+            linear.add_color_stop(offset.to_f, color)
+          end
+          @cairo_cxt.set_source(linear)
+        elsif match = arg.match(RADIAL_GRADIENT)
+          x1, y1, r1, x2, y2, r2  = match.captures
+          linear = Cairo::RadialPattern.new(x1.to_f, y1.to_f, r1.to_f,
+                                            x2.to_f, y2.to_f, r2.to_f)
+          arg.scan(STOPS).each do |color, offset|
+            linear.add_color_stop(offset.to_f, color)
+          end
+          @cairo_cxt.set_source(linear)
+        else
+          @cairo_cxt.set_source_color(arg)
+        end
+      end
+    end
+  end
+end

lib/squib/graphics/gradient_regex.rb

@@ -0,0 +1,46 @@
+module Squib
+  module Graphics
+    STOPS = /   # used to capture the stops
+      \s*         # leading whitespace is ok
+      (\#?[\w]+)  # color
+      @           # no spaces here
+      (\d+\.?\d*) # offset number
+    /x
+
+    LINEAR_GRADIENT = /
+      \( \s*      # coordinate 1
+         (\d+\.?\d*) \s* # x1 number
+         ,\s*            # whitespace after comma is ok
+         (\d+\.?\d*) \s* # y1 number
+      \)
+      \s*        # space between coordinates is ok
+      \( \s*      # coordinate 2
+         (\d+\.?\d*) \s* # x2 number
+         ,\s*            # whitespace after comma is ok
+         (\d+\.?\d*) \s* # y2 number
+      \)
+      (#{STOPS})+ # stops
+      \s*         # trailing whitespace is ok
+    /x
+
+    RADIAL_GRADIENT = /
+      \( \s*      # coordinate 1
+        (\d+\.?\d*) \s* # x1 number
+        ,\s*            # whitespace after comma is ok
+        (\d+\.?\d*) \s* # y1 number
+        ,\s*            # whitespace after comma is ok
+        (\d+\.?\d*) \s* # r1 number
+      \)
+      \s*         # space between coordinates is ok
+      \( \s*      # coordinate 2
+        (\d+\.?\d*) \s* # x2 number
+        ,\s*            # whitespace after comma is ok
+        (\d+\.?\d*) \s* # y2 number
+        ,\s*            # whitespace after comma is ok
+        (\d+\.?\d*) \s* # r2 number
+      \)
+      (#{STOPS})+ # stops
+      \s*         # trailing whitespace is ok
+    /x
+  end
+end

lib/squib/graphics/shapes.rb

@@ -8,11 +8,11 @@ def rect(x, y, width, height, x_radius, y_radius, fill_color, stroke_color, stro
       height = @height  if height == :native
       use_cairo do |cc|
         cc.rounded_rectangle(x, y, width, height, x_radius, y_radius)
-        cc.set_source_color(stroke_color)
+        cc.set_source_squibcolor(stroke_color)
         cc.set_line_width(stroke_width)
         cc.stroke
         cc.rounded_rectangle(x, y, width, height, x_radius, y_radius)
-        cc.set_source_color(fill_color)
+        cc.set_source_squibcolor(fill_color)
         cc.fill
       end
     end
@@ -22,11 +22,11 @@ def rect(x, y, width, height, x_radius, y_radius, fill_color, stroke_color, stro
     def circle(x, y, radius, fill_color, stroke_color, stroke_width)
       use_cairo do |cc|
         cc.circle(x, y, radius)
-        cc.set_source_color(stroke_color)
+        cc.set_source_squibcolor(stroke_color)
         cc.set_line_width(stroke_width)
         cc.stroke
         cc.circle(x, y, radius)
-        cc.set_source_color(fill_color)
+        cc.set_source_squibcolor(fill_color)
         cc.fill
       end
     end
@@ -36,11 +36,11 @@ def circle(x, y, radius, fill_color, stroke_color, stroke_width)
     def triangle(x1, y1, x2, y2, x3, y3, fill_color, stroke_color, stroke_width)
       use_cairo do |cc|
         cc.triangle(x1, y1, x2, y2, x3, y3)
-        cc.set_source_color(stroke_color)
+        cc.set_source_squibcolor(stroke_color)
         cc.set_line_width(stroke_width)
         cc.stroke
         cc.triangle(x1, y1, x2, y2, x3, y3)
-        cc.set_source_color(fill_color)
+        cc.set_source_squibcolor(fill_color)
         cc.fill
       end
     end
@@ -51,7 +51,7 @@ def line(x1, y1, x2, y2, stroke_color, stroke_width)
       use_cairo do |cc|
         cc.move_to(x1, y1)
         cc.line_to(x2, y2)
-        cc.set_source_color(stroke_color)
+        cc.set_source_squibcolor(stroke_color)
         cc.set_line_width(stroke_width)
         cc.stroke
       end

lib/squib/graphics/text.rb

@@ -91,7 +91,7 @@ def text(str, font, font_size, color,
       Squib.logger.debug {"Placing '#{str}'' with font '#{font}' @ #{x}, #{y}, color: #{color}, angle: #{angle} etc."}
       extents = nil
       use_cairo do |cc|
-        cc.set_source_color(color)
+        cc.set_source_squibcolor(color)
         cc.translate(x,y)
         cc.rotate(angle)
         cc.translate(-1*x,-1*y)

lib/squib/input_helpers.rb

@@ -132,7 +132,8 @@ def colorify(opts, nillable=false, key=:color)
           if @custom_colors.key? color.to_s
             color = @custom_colors[color.to_s]
           end
-          opts[key][i] = Cairo::Color.parse(color)
+          # opts[key][i] = Cairo::Color.parse(color)
+          color
         end
       end
       Squib.logger.debug {"After colorify: #{opts}"}

samples/colors.rb

@@ -7,10 +7,13 @@
   text color: '#f00', str: '3-hex', x: 50, y: y+=50
   text color: '#f00', str: '3-hex (alpha)', x: 50, y: y+=50
   text color: '#ff0000', str: '6-hex', x: 50, y: y+=50
-  text color: '#ff000099', str: '8-hex(alpha) *', x: 50, y: y+=50
+  text color: '#ff000099', str: '8-hex(alpha)', x: 50, y: y+=50
   text color: '#ffff00000000', str: '12-hex', x: 50, y: y+=50
   text color: '#ffff000000009999', str: '12-hex (alpha)', x: 50, y: y+=50
   text color: :burnt_orange, str: 'Symbols of constants too', x: 50, y: y+=50
+  text color: '(0,0)(400,0) blue@0.0 red@1.0', str: 'Linear gradients!', x: 50, y: y+=50
+  text color: '(200,500,10)(200,500,100) blue@0.0 red@1.0', str: 'Radial gradients!', x: 50, y: y+=50
+  # see gradients.rb sample for more on gradients
 
   save_png prefix: 'colors_'
 end

samples/gradients.rb

@@ -0,0 +1,14 @@
+require 'squib'
+
+Squib::Deck.new do
+  # Just about anywhere Squib takes in a color it can also take in a gradient too
+  # Note that we need to provide xy coordinates.
+  # These are relative to the xy provided the command.
+  background color: '(0,0)(0,1125) #ccc@0.0 #111@1.0'
+
+  # Radial gradients look like this
+  circle  x: 415, y: 415, radius: 100, stroke_color: '#0000',
+          fill_color: '(425,400,2)(425,400,120) #ccc@0.0 #111@1.0'
+
+  save_png prefix: 'gradient_'
+end

spec/graphics/cairo_context_wrapper_spec.rb

@@ -0,0 +1,75 @@
+require 'spec_helper'
+require 'squib/graphics/cairo_context_wrapper'
+
+describe Squib::Graphics::CairoContextWrapper do
+
+  let(:cairo) { double(Cairo::Context) }
+  subject     { Squib::Graphics::CairoContextWrapper.new(cairo) }
+
+  it 'passes on colors as normal' do
+    expect(cairo).to receive(:set_source_color).with('blue')
+    subject.set_source_squibcolor('blue')
+  end
+
+  it 'passes on color symbols as normal' do
+    expect(cairo).to receive(:set_source_color).with(:blue)
+    subject.set_source_squibcolor(:blue)
+  end
+
+  it 'passes on color hashes' do
+    expect(cairo).to receive(:set_source_color)
+      .with('#aabbccdd')
+    subject.set_source_squibcolor('#aabbccdd')
+  end
+
+  context 'regex variations for linear gradients' do
+    before(:each) do
+      dbl = double(Cairo::LinearPattern)
+      expect(Cairo::LinearPattern).to receive(:new).with(1,2,3,4).and_return(dbl)
+      expect(dbl).to   receive(:add_color_stop).with(0.0, 'blue')
+      expect(dbl).to   receive(:add_color_stop).with(1.0, 'red')
+      expect(cairo).to receive(:set_source).with(dbl)
+    end
+
+    it('handles no decimals'  ) { subject.set_source_squibcolor('(1,2) (3,4) blue@0 red@1') }
+    it('handles decimals'     ) { subject.set_source_squibcolor('(1.0,2.0) (3.0,4.0) blue@0 red@1') }
+    it('handles no whitespace') { subject.set_source_squibcolor('(1,2)(3,4)blue@0red@1') }
+    it('handles whitespace'   ) { subject.set_source_squibcolor('  (  1  ,  2  )  ( 3  ,  4  )  blue@0   red@1   ') }
+  end
+
+  context 'regex variations for radial gradients' do
+    before(:each) do
+      dbl = double(Cairo::RadialPattern)
+      expect(Cairo::RadialPattern).to receive(:new).with(1,2,5,3,4,6).and_return(dbl)
+      expect(dbl).to   receive(:add_color_stop).with(0.0, 'blue')
+      expect(dbl).to   receive(:add_color_stop).with(1.0, 'red')
+      expect(cairo).to receive(:set_source).with(dbl)
+    end
+
+    it('handles no decimals'  ) { subject.set_source_squibcolor('(1,2,5) (3,4,6) blue@0 red@1') }
+    it('handles decimals'     ) { subject.set_source_squibcolor('(1.0,2.0,5.0) (3.0,4.0,6.0) blue@0 red@1') }
+    it('handles no whitespace') { subject.set_source_squibcolor('(1,2,5)(3,4,6)blue@0red@1') }
+    it('handles whitespace'   ) { subject.set_source_squibcolor('  (  1  ,  2  , 5 )  ( 3  ,  4 , 6 )  blue@0   red@1   ') }
+  end
+
+  context 'regex handles hash notation' do
+    it 'on radial patterns' do
+      dbl = double(Cairo::RadialPattern)
+      expect(Cairo::RadialPattern).to receive(:new).with(1,2,5,3,4,6).and_return(dbl)
+      expect(dbl).to   receive(:add_color_stop).with(0.0, '#def')
+      expect(dbl).to   receive(:add_color_stop).with(1.0, '#112233')
+      expect(cairo).to receive(:set_source).with(dbl)
+      subject.set_source_squibcolor('(1,2,5) (3,4,6) #def@0 #112233@1')
+    end
+
+    it 'on linear patterns' do
+      dbl = double(Cairo::LinearPattern)
+      expect(Cairo::LinearPattern).to receive(:new).with(1,2,3,4).and_return(dbl)
+      expect(dbl).to   receive(:add_color_stop).with(0.0, '#def')
+      expect(dbl).to   receive(:add_color_stop).with(1.0, '#112233')
+      expect(cairo).to receive(:set_source).with(dbl)
+      subject.set_source_squibcolor('(1,2) (3,4) #def@0 #112233@1')
+    end
+  end
+
+end