Add social preview image and generation script

Author: schulzchristian

img/gen_social_preview.py

@@ -0,0 +1,247 @@
+#!/usr/bin/env python3
+"""Generate GitHub social preview image for CHSZLabLib (1280x640)."""
+
+from PIL import Image, ImageDraw, ImageFont
+import math
+
+W, H = 1280, 640
+
+# Colors
+BG_DARK = (15, 23, 42)        # slate-900
+BG_MID = (30, 41, 59)         # slate-800
+ACCENT = (59, 130, 246)       # blue-500
+ACCENT_LIGHT = (96, 165, 250) # blue-400
+WHITE = (255, 255, 255)
+GRAY = (148, 163, 184)        # slate-400
+LIGHT_GRAY = (203, 213, 225)  # slate-300
+GREEN = (34, 197, 94)         # green-500
+PURPLE = (168, 85, 247)       # purple-500
+ORANGE = (249, 115, 22)       # orange-500
+CYAN = (6, 182, 212)          # cyan-500
+
+# Fonts
+font_bold_64 = ImageFont.truetype("/usr/share/fonts/opentype/inter/Inter-Bold.otf", 64)
+font_bold_48 = ImageFont.truetype("/usr/share/fonts/opentype/inter/Inter-Bold.otf", 48)
+font_semi_28 = ImageFont.truetype("/usr/share/fonts/opentype/inter/Inter-SemiBold.otf", 28)
+font_med_24 = ImageFont.truetype("/usr/share/fonts/opentype/inter/Inter-Medium.otf", 24)
+font_reg_22 = ImageFont.truetype("/usr/share/fonts/opentype/inter/Inter-Regular.otf", 22)
+font_mono_20 = ImageFont.truetype("/home/c_schulz/.local/share/fonts/FiraCodeNerdFont-Bold.ttf", 20)
+font_mono_18 = ImageFont.truetype("/home/c_schulz/.local/share/fonts/FiraCodeNerdFont-Bold.ttf", 18)
+
+img = Image.new("RGB", (W, H), BG_DARK)
+draw = ImageDraw.Draw(img)
+
+# Subtle gradient overlay (top to bottom)
+for y in range(H):
+    alpha = y / H
+    r = int(BG_DARK[0] * (1 - alpha * 0.3) + BG_MID[0] * (alpha * 0.3))
+    g = int(BG_DARK[1] * (1 - alpha * 0.3) + BG_MID[1] * (alpha * 0.3))
+    b = int(BG_DARK[2] * (1 - alpha * 0.3) + BG_MID[2] * (alpha * 0.3))
+    draw.line([(0, y), (W, y)], fill=(r, g, b))
+
+# Draw decorative graph nodes and edges in background
+nodes = [
+    (95, 120, 8, ACCENT),
+    (180, 80, 6, PURPLE),
+    (140, 200, 7, CYAN),
+    (250, 150, 5, GREEN),
+    (60, 250, 6, ACCENT_LIGHT),
+    (200, 280, 5, ORANGE),
+    # Right side
+    (1100, 100, 7, ACCENT),
+    (1200, 160, 6, PURPLE),
+    (1150, 250, 8, CYAN),
+    (1050, 200, 5, GREEN),
+    (1220, 80, 5, ACCENT_LIGHT),
+    (1080, 310, 6, ORANGE),
+    # Bottom corners
+    (100, 500, 6, ACCENT),
+    (200, 550, 5, PURPLE),
+    (1150, 520, 7, CYAN),
+    (1050, 570, 5, GREEN),
+    (160, 580, 4, ACCENT_LIGHT),
+    (1200, 560, 5, ORANGE),
+]
+
+edges = [
+    (0, 1), (0, 2), (1, 3), (2, 4), (2, 5), (3, 5), (4, 5),
+    (6, 7), (6, 8), (7, 9), (8, 9), (6, 10), (8, 11), (9, 11),
+    (12, 13), (13, 16), (12, 16),
+    (14, 15), (14, 17), (15, 17),
+]
+
+for i, j in edges:
+    x1, y1 = nodes[i][0], nodes[i][1]
+    x2, y2 = nodes[j][0], nodes[j][1]
+    c = tuple(int(v * 0.25) for v in nodes[i][3])
+    draw.line([(x1, y1), (x2, y2)], fill=c, width=2)
+
+for x, y, r, color in nodes:
+    faded = tuple(int(v * 0.4) for v in color)
+    draw.ellipse([x - r, y - r, x + r, y + r], fill=faded)
+    # inner bright dot
+    r2 = max(2, r - 3)
+    bright = tuple(min(255, int(v * 0.6)) for v in color)
+    draw.ellipse([x - r2, y - r2, x + r2, y + r2], fill=bright)
+
+# Accent line at top
+draw.rectangle([0, 0, W, 4], fill=ACCENT)
+
+# Title — "CHSZ" in red, "LabLib" in white
+RED = (220, 38, 38)
+part1 = "CHSZ"
+part2 = "LabLib"
+bbox1 = draw.textbbox((0, 0), part1, font=font_bold_64)
+bbox2 = draw.textbbox((0, 0), part2, font=font_bold_64)
+tw = (bbox1[2] - bbox1[0]) + (bbox2[2] - bbox2[0])
+tx = (W - tw) // 2
+draw.text((tx, 100), part1, fill=RED, font=font_bold_64)
+tx += bbox1[2] - bbox1[0]
+draw.text((tx, 100), part2, fill=WHITE, font=font_bold_64)
+
+# Subtitle
+sub = "State-of-the-art graph algorithms from C++ to Python"
+bbox = draw.textbbox((0, 0), sub, font=font_semi_28)
+sw = bbox[2] - bbox[0]
+draw.text(((W - sw) // 2, 185), sub, fill=LIGHT_GRAY, font=font_semi_28)
+
+# Divider
+div_y = 235
+div_w = 200
+draw.line([(W // 2 - div_w, div_y), (W // 2 + div_w, div_y)], fill=ACCENT, width=2)
+
+# Module boxes
+modules = [
+    ("Decomposition", "Partition, Cuts, Cluster", ACCENT),
+    ("Independence", "MIS, MWIS, HyperMIS", GREEN),
+    ("Orientation", "Edge Orientation", PURPLE),
+    ("Dynamic", "Dynamic Problems", ORANGE),
+]
+
+box_w = 250
+box_h = 90
+gap = 30
+total_w = len(modules) * box_w + (len(modules) - 1) * gap
+start_x = (W - total_w) // 2
+box_y = 265
+
+for i, (name, desc, color) in enumerate(modules):
+    x = start_x + i * (box_w + gap)
+    # Box background
+    box_color = tuple(int(v * 0.15) + BG_DARK[j] for j, v in enumerate(color))
+    draw.rounded_rectangle([x, box_y, x + box_w, box_y + box_h], radius=10, fill=box_color)
+    # Border
+    border_color = tuple(int(v * 0.5) for v in color)
+    draw.rounded_rectangle([x, box_y, x + box_w, box_y + box_h], radius=10, outline=border_color, width=2)
+    # Top accent
+    draw.line([(x + 10, box_y + 1), (x + box_w - 10, box_y + 1)], fill=color, width=2)
+    # Name
+    bbox = draw.textbbox((0, 0), name, font=font_med_24)
+    nw = bbox[2] - bbox[0]
+    draw.text((x + (box_w - nw) // 2, box_y + 15), name, fill=WHITE, font=font_med_24)
+    # Description
+    bbox = draw.textbbox((0, 0), desc, font=font_reg_22)
+    dw = bbox[2] - bbox[0]
+    draw.text((x + (box_w - dw) // 2, box_y + 50), desc, fill=GRAY, font=font_reg_22)
+
+# Code snippet
+code_y = 390
+code_bg = (22, 30, 48)
+code_h = 130
+code_w = 700
+code_x = (W - code_w) // 2
+draw.rounded_rectangle([code_x, code_y, code_x + code_w, code_y + code_h], radius=12, fill=code_bg)
+draw.rounded_rectangle([code_x, code_y, code_x + code_w, code_y + code_h], radius=12, outline=(51, 65, 85), width=1)
+
+# Terminal dots
+for ci, col in enumerate([(239, 68, 68), (250, 204, 21), (34, 197, 94)]):
+    draw.ellipse([code_x + 16 + ci * 20, code_y + 12, code_x + 28 + ci * 20, code_y + 24], fill=col)
+
+lines = [
+    ("from", (198, 120, 221)),  # keyword
+    (" chszlablib ", LIGHT_GRAY),
+    ("import", (198, 120, 221)),
+    (" Graph, Decomposition", (230, 192, 123)),
+]
+lx = code_x + 20
+ly = code_y + 40
+for text, color in lines:
+    draw.text((lx, ly), text, fill=color, font=font_mono_18)
+    bbox = draw.textbbox((0, 0), text, font=font_mono_18)
+    lx += bbox[2] - bbox[0]
+
+# Second line
+lx = code_x + 20
+ly = code_y + 68
+line2 = [
+    ("g = Graph(", LIGHT_GRAY),
+    ("n=100", (230, 192, 123)),
+    (").add_edges(", LIGHT_GRAY),
+    ("edges", (152, 195, 121)),
+    (").finalize()", LIGHT_GRAY),
+]
+for text, color in line2:
+    draw.text((lx, ly), text, fill=color, font=font_mono_18)
+    bbox = draw.textbbox((0, 0), text, font=font_mono_18)
+    lx += bbox[2] - bbox[0]
+
+# Third line
+lx = code_x + 20
+ly = code_y + 96
+line3 = [
+    ("result = Decomposition.partition(g, k=", LIGHT_GRAY),
+    ("4", (230, 192, 123)),
+    (")", LIGHT_GRAY),
+]
+for text, color in line3:
+    draw.text((lx, ly), text, fill=color, font=font_mono_18)
+    bbox = draw.textbbox((0, 0), text, font=font_mono_18)
+    lx += bbox[2] - bbox[0]
+
+# Footer
+footer = "Algorithm Engineering Group, Heidelberg University"
+bbox = draw.textbbox((0, 0), footer, font=font_reg_22)
+fw = bbox[2] - bbox[0]
+
+# Badges row — colors from README shields.io badges
+badges = ["Python 3.9+", "C++17", "pybind11"]
+badge_font = font_mono_20
+badge_gap = 20
+badge_colors = [
+    (0x37, 0x76, 0xab),  # #3776ab — Python badge
+    (0x00, 0x59, 0x9C),  # #00599C — C++ badge
+    (0x06, 0x4F, 0x8C),  # #064F8C — build/cmake badge
+]
+
+# Measure total width
+total_badge_w = 0
+badge_dims = []
+for b in badges:
+    bbox = draw.textbbox((0, 0), b, font=badge_font)
+    bw = bbox[2] - bbox[0] + 24
+    bh = 30
+    badge_dims.append((bw, bh))
+    total_badge_w += bw
+total_badge_w += (len(badges) - 1) * badge_gap
+
+bx = (W - total_badge_w) // 2
+by = 548
+
+for i, (b, (bw, bh)) in enumerate(zip(badges, badge_dims)):
+    col = badge_colors[i]
+    bg = tuple(int(v * 0.3) for v in col)
+    draw.rounded_rectangle([bx, by, bx + bw, by + bh], radius=5, fill=bg)
+    draw.rounded_rectangle([bx, by, bx + bw, by + bh], radius=5, outline=col, width=1)
+    bbox = draw.textbbox((0, 0), b, font=badge_font)
+    tw = bbox[2] - bbox[0]
+    th = bbox[3] - bbox[1]
+    draw.text((bx + (bw - tw) // 2, by + (bh - th) // 2 - 2), b, fill=WHITE, font=badge_font)
+    bx += bw + badge_gap
+
+# Footer text below badges
+draw.text(((W - fw) // 2, 588), footer, fill=GRAY, font=font_reg_22)
+
+out = "/home/c_schulz/projects/coding/CHSZLabLib/social-preview.png"
+img.save(out, "PNG")
+print(f"Saved: {out}")
+print(f"Size: {img.size}")