Improved rendering of memes

main.lua

@@ -117,6 +117,30 @@ local function load_random_font ()
     return font_name
 end
 
+local DROSTE_EFFECT_TRIGGERS = {
+    ['induktion'] = true,
+    ['rekursion'] = true,
+    ['uendelig rekursion'] = true,
+    ['rekursive'] = true,
+    ['rekursive funktioner'] = true,
+    ['recursion'] = true,
+    ['infinite recursion'] = true,
+    ['tail recursion'] = true,
+    ['recursive'] = true,
+    ['recursive function'] = true,
+    ['induktion'] = true,
+    ['droste']    = true,
+    ['drostle']   = true, -- Misspelling
+
+    ['uendelig'] = true,
+    ['uendeligt'] = true,
+
+    ['strange loop'] = true,
+    ['loop'] = true,
+}
+
+local DROSTE_ITERATIONS_DEFAULT = 5
+
 local function fill_in_topics_information (topics)
     assert(type(topics) == 'table')
     --
@@ -127,9 +151,9 @@ local function fill_in_topics_information (topics)
         assert(type(topic) == 'string')
 
         local url = topic_to_image_url[topic]
-        print(topic, url)
 
-        if url then  new_topics[i]  =  { topic = topic, type = 'image', url = url }
+        if DROSTE_EFFECT_TRIGGERS[topic] then  new_topics[i]  =  { topic = topic, type = 'droste'             }
+        elseif url                       then  new_topics[i]  =  { topic = topic, type = 'image', url = url   }
         else                                   new_topics[i]  =  { topic = topic, type = 'text', text = topic }
         end
     end
@@ -162,6 +186,8 @@ local function paste_topic_onto_image (target, topic, x, y, w, h, bg_color, font
     elseif topic.type == 'text' then
         local text = topic.text
         draw_centered_text_in_box(font_name, target, text, x, y, w, h, bg_color)
+    elseif topic.type == 'droste' then
+        target:fill_rectangle(x, y, w, h, COLOR_WHITE)
     else
         assert(false, topic.type)
     end
@@ -185,6 +211,34 @@ local function save_to_cloud (img)
     return CONFIG.STORAGE_DIR_URL..img_name
 end
 
+
+local function draw_droste_effect (target_image, droste_positions, iterations)
+    iterations = interations or DROSTE_ITERATIONS_DEFAULT
+    if #droste_positions <= 0 or iterations <= 0 then  return target_image  end
+    for _ = 1, iterations do
+        for _, position in ipairs(droste_positions) do
+            local paste_image = target_image:clone()
+                  paste_image:crop_and_scale(0, 0, paste_image:get_width(), paste_image:get_height(), position.w, position.h)
+            flatten_onto (target_image, paste_image, position.x, position.y)
+            paste_image:free()
+        end
+    end
+    return target_image
+end
+
+local function droste_positions_from_topics (topics, places)
+    local droste_poss = {}
+    for i, topic in ipairs(topics) do
+        if topic.type == 'droste' then
+            droste_poss[#droste_poss+1] = {
+                x = places[i].x,  y = places[i].y,
+                w = places[i].w,  h = places[i].h,
+            }
+        end
+    end
+    return droste_poss
+end
+
 local function generate_distracted_boyfriend (topics)
     assert(type(topics) == 'table' and #topics == 2)
 
@@ -194,32 +248,57 @@ local function generate_distracted_boyfriend (topics)
 
     local HEAD_W, HEAD_H = 150, 150
 
-    local x1, y1  =  640 + math.random(-20, 20), 50 + math.random(-20, 20)
+    local DISTRACTED_BOYFRIEND_POS = {
-    local x2, y2  =  180 + math.random(-20, 20), 50 + math.random(-20, 20)
+        { x = 640 + math.random(-20, 20), y = 50 + math.random(-20, 20), w = HEAD_W, h = HEAD_H },
-    paste_topic_onto_image(base_img, topics[1], x1, y1, HEAD_W, HEAD_H, nil, font_name)
+        { x = 180 + math.random(-20, 20), y = 50 + math.random(-20, 20), w = HEAD_W, h = HEAD_H },
-    paste_topic_onto_image(base_img, topics[2], x2, y2, HEAD_W, HEAD_H, nil, font_name)
+    }
+
+    -- Paste topic onto head
+    for index, pos in ipairs(DISTRACTED_BOYFRIEND_POS) do
+        paste_topic_onto_image(base_img, topics[index], pos.x, pos.y, pos.w, pos.h, nil, font_name)
+    end
+
+    -- Droste
+    base_img = draw_droste_effect(base_img, droste_positions_from_topics(topics, DISTRACTED_BOYFRIEND_POS))
 
     --
     return save_to_cloud(base_img)
 end
 
+local BRAIN_ROW_HEIGHT = 150
+local BRAIN_ROW_WIDTH  = 200
+
+local BRAIN_MAX_EXPLOSION_TOPICS  =  6
+local BRAIN_DROSTE_POS = {}
+for i = 1, BRAIN_MAX_EXPLOSION_TOPICS do
+    BRAIN_DROSTE_POS[i] = {
+        x = 0,
+        y = (i-1) * BRAIN_ROW_HEIGHT,
+        w = BRAIN_ROW_WIDTH,
+        h = BRAIN_ROW_HEIGHT
+    }
+end
+
+
 local function generate_brain_explosion_image (topics)
-    assert(type(topics) == 'table' and 1 <= #topics and #topics <= 6)
+    assert(type(topics) == 'table' and 1 <= #topics and #topics <= BRAIN_MAX_EXPLOSION_TOPICS)
     --
-    local ROW_HEIGHT = 150
+    local base_img = imlib.image.new(BRAIN_ROW_WIDTH * 2, BRAIN_ROW_HEIGHT * #topics)
-    local ROW_WIDTH  = 200
-    local base_img = imlib.image.new(ROW_WIDTH * 2, ROW_HEIGHT * #topics)
     local font_name = choose_random_font()
     --
     for i, topic_info in ipairs(topics) do
-        paste_topic_onto_image(base_img, topic_info, 0, (i-1) * ROW_HEIGHT, ROW_WIDTH, ROW_HEIGHT, COLOR_WHITE, font_name)
+        paste_topic_onto_image(base_img, topic_info, 0, (i-1) * BRAIN_ROW_HEIGHT, BRAIN_ROW_WIDTH, BRAIN_ROW_HEIGHT, COLOR_WHITE, font_name)
 
         local brain_img  =  imlib.image.load(CONFIG.IMGGEN_PATH_BRAINS..'brain_'..i..'.png')
-              brain_img:crop_and_scale(0, 0, brain_img:get_width(), brain_img:get_height(), ROW_WIDTH, ROW_HEIGHT)
+              brain_img:crop_and_scale(0, 0, brain_img:get_width(), brain_img:get_height(), BRAIN_ROW_WIDTH, BRAIN_ROW_HEIGHT)
-        flatten_onto (base_img, brain_img, ROW_WIDTH, (i-1) * ROW_HEIGHT)
+        flatten_onto (base_img, brain_img, BRAIN_ROW_WIDTH, (i-1) * BRAIN_ROW_HEIGHT)
         brain_img:free()
     end
 
+    -- Droste
+    base_img = draw_droste_effect(base_img, droste_positions_from_topics(topics, BRAIN_DROSTE_POS))
+
+    -- Save
     return save_to_cloud(base_img)
 end