""" ════════════════════════════════════════════════════════════ MODULE 8 — Script 01: Gravity, Velocity & Jumping ════════════════════════════════════════════════════════════ What this demonstrates: • Velocity and acceleration as vectors updated each frame • Gravity as constant downward acceleration • Variable jump height (short tap vs hold) • Coyote time — jump grace period after walking off a ledge • Jump buffering — input registered slightly before landing • Terminal velocity — cap on falling speed • Debug panel showing all physics values live Controls: • A / D: move left / right • SPACE: jump (hold for higher jump) • G: toggle gravity on/off • +/-: increase / decrease gravity strength • F1: toggle debug overlay • R: reset player • ESC: quit ════════════════════════════════════════════════════════════ """ import pygame import sys import math pygame.init() WIDTH, HEIGHT = 900, 620 FPS = 60 TS = 40 BLACK = (0, 0, 0) WHITE = (255, 255, 255) GRAY = (60, 60, 60) GRAY_LT = (150, 150, 150) BLUE = (50, 120, 220) BLUE_LT = (100, 160, 255) GREEN = (50, 200, 100) RED = (220, 80, 70) YELLOW = (255, 220, 50) ORANGE = (255, 160, 30) PURPLE = (160, 90, 220) CYAN = (50, 200, 220) DARK_BG = (10, 10, 20) MAROON = (100, 55, 30) screen = pygame.display.set_mode((WIDTH, HEIGHT)) pygame.display.set_caption("Module 8 — Gravity & Jumping") clock = pygame.time.Clock() F_SM = pygame.font.SysFont("monospace", 12) F_MD = pygame.font.SysFont("monospace", 15) F_LG = pygame.font.SysFont("monospace", 20, bold=True) F_TIT = pygame.font.SysFont("monospace", 26, bold=True) def blit(surf, txt, pos, color=WHITE, font=None): surf.blit((font or F_MD).render(txt, True, color), pos) def blit_c(surf, txt, y, color=WHITE, font=None): s = (font or F_MD).render(txt, True, color) surf.blit(s, (WIDTH // 2 - s.get_width() // 2, y)) def bar(surf, x, y, w, h, value, vmin, vmax, color, label=""): """Draw a value bar from vmin to vmax.""" pygame.draw.rect(surf, GRAY, (x, y, w, h)) pct = (value - vmin) / (vmax - vmin) pct = max(0.0, min(1.0, pct)) fill_w= int(w * pct) pygame.draw.rect(surf, color, (x, y, fill_w, h)) pygame.draw.rect(surf, GRAY_LT, (x, y, w, h), 1) # Center line (zero) if vmin < 0 < vmax: zx = x + int(w * (-vmin) / (vmax - vmin)) pygame.draw.line(surf, WHITE, (zx, y), (zx, y + h), 1) if label: blit(surf, label, (x + w + 6, y - 1), GRAY_LT, F_SM) # ══════════════════════════════════════════════════════════ # PLATFORM LAYOUT # ══════════════════════════════════════════════════════════ PLATFORMS = [ pygame.Rect(0, 560, WIDTH, 60), # Ground pygame.Rect(100, 440, 160, 16), pygame.Rect(320, 380, 120, 16), pygame.Rect(500, 300, 180, 16), pygame.Rect(700, 400, 140, 16), pygame.Rect(200, 260, 100, 16), pygame.Rect(580, 200, 120, 16), pygame.Rect(50, 170, 80, 16), ] def draw_platforms(surf): for p in PLATFORMS: pygame.draw.rect(surf, (70, 100, 55), p) pygame.draw.rect(surf, (90, 140, 70), p, 2) # Top edge highlight pygame.draw.line(surf, (110, 170, 85), p.topleft, p.topright, 2) # ══════════════════════════════════════════════════════════ # PHYSICS CONSTANTS (all tweakable with +/-) # ══════════════════════════════════════════════════════════ GRAVITY_DEFAULT = 900.0 # px/s² JUMP_VELOCITY = -480.0 # px/s (negative = upward) MOVE_SPEED = 220.0 # px/s horizontal FRICTION = 0.78 # multiplied each frame when no key held TERMINAL_VEL = 900.0 # max falling speed px/s COYOTE_FRAMES = 8 # frames of grace after walking off ledge JUMP_BUFFER_FRAMES = 10 # frames jump input is remembered before landing # Variable jump: hold SPACE for full jump, release early for short jump MIN_JUMP_FRAMES = 6 # minimum frames gravity is reduced while jumping MAX_JUMP_FRAMES = 20 # maximum frames of reduced gravity # ══════════════════════════════════════════════════════════ # PLAYER # ══════════════════════════════════════════════════════════ class Player: W, H = 28, 38 def __init__(self): self.reset() def reset(self): self.x = 60.0 self.y = 510.0 self.vx = 0.0 self.vy = 0.0 self.on_ground= False self.facing = 1 # Coyote time self.coyote_timer = 0 # Jump buffer self.jump_buffer = 0 # Variable jump state self.jumping = False self.jump_frames = 0 # Stats for HUD self.max_vy = 0.0 self.jumps_done = 0 self.coyote_used = 0 @property def rect(self): return pygame.Rect(int(self.x), int(self.y), self.W, self.H) def update(self, dt, gravity, gravity_on): keys = pygame.key.get_pressed() # ── Horizontal movement ─────────────────────────── if keys[pygame.K_a]: self.vx = -MOVE_SPEED self.facing = -1 elif keys[pygame.K_d]: self.vx = MOVE_SPEED self.facing = 1 else: self.vx *= FRICTION # Friction deceleration if abs(self.vx) < 1: self.vx = 0 # ── Coyote time counter ─────────────────────────── if self.on_ground: self.coyote_timer = COYOTE_FRAMES elif self.coyote_timer > 0: self.coyote_timer -= 1 # ── Jump buffer counter ─────────────────────────── if self.jump_buffer > 0: self.jump_buffer -= 1 # ── Can we jump? ────────────────────────────────── can_jump = self.on_ground or self.coyote_timer > 0 if self.jump_buffer > 0 and can_jump: was_coyote = not self.on_ground and self.coyote_timer > 0 self.vy = JUMP_VELOCITY self.jumping = True self.jump_frames = 0 self.jump_buffer = 0 self.coyote_timer= 0 self.jumps_done += 1 if was_coyote: self.coyote_used += 1 # ── Variable jump: reduce gravity while holding ─── if self.jumping: self.jump_frames += 1 if not keys[pygame.K_SPACE] and self.jump_frames > MIN_JUMP_FRAMES: self.jumping = False # Cut jump short if self.jump_frames >= MAX_JUMP_FRAMES: self.jumping = False # ── Apply gravity ───────────────────────────────── if gravity_on: grav_mult = 0.4 if self.jumping else 1.0 # Reduced during jump hold self.vy += gravity * grav_mult * dt self.vy = min(self.vy, TERMINAL_VEL) self.max_vy = max(self.max_vy, abs(self.vy)) # ── Integrate position ──────────────────────────── # Move X, resolve collisions self.x += self.vx * dt self._resolve_x() # Move Y, resolve collisions prev_on_ground = self.on_ground self.on_ground = False self.y += self.vy * dt self._resolve_y() # Clamp to screen self.x = max(0, min(self.x, WIDTH - self.W)) if self.y > HEIGHT: self.reset() def _resolve_x(self): r = self.rect for p in PLATFORMS: if r.colliderect(p): if self.vx > 0: self.x = p.left - self.W elif self.vx < 0: self.x = p.right self.vx = 0 def _resolve_y(self): r = self.rect for p in PLATFORMS: if r.colliderect(p): if self.vy > 0: self.y = p.top - self.H self.vy = 0 self.on_ground = True self.jumping = False elif self.vy < 0: self.y = p.bottom self.vy = 0 def draw(self, surf): sx, sy = int(self.x), int(self.y) # Shadow if self.on_ground: pygame.draw.ellipse(surf, (0, 0, 0), (sx + 2, sy + self.H - 4, self.W - 4, 8)) # Body col = BLUE_LT if self.jumping else BLUE pygame.draw.rect(surf, col, (sx, sy, self.W, self.H), border_radius=5) pygame.draw.rect(surf, WHITE, (sx, sy, self.W, self.H), 1, border_radius=5) # Eyes ex = sx + (self.W - 10 if self.facing > 0 else 6) pygame.draw.circle(surf, WHITE, (ex, sy + 12), 5) pygame.draw.circle(surf, BLACK, (ex + self.facing, sy + 12), 3) # Velocity vector arrow scale = 0.12 cx = sx + self.W // 2 cy = sy + self.H // 2 ex2 = cx + int(self.vx * scale) ey2 = cy + int(self.vy * scale) if abs(self.vx) > 5 or abs(self.vy) > 5: pygame.draw.line(surf, YELLOW, (cx, cy), (ex2, ey2), 2) pygame.draw.circle(surf, YELLOW, (ex2, ey2), 3) def draw_debug(self, surf): # Coyote timer bar if self.coyote_timer > 0: pct = self.coyote_timer / COYOTE_FRAMES bx = int(self.x) - 5 pygame.draw.rect(surf, ORANGE, (bx, int(self.y) - 10, int(38 * pct), 5)) blit(surf, "coyote", (bx, int(self.y) - 22), ORANGE, F_SM) # Jump buffer bar if self.jump_buffer > 0: pct = self.jump_buffer / JUMP_BUFFER_FRAMES bx = int(self.x) - 5 pygame.draw.rect(surf, CYAN, (bx, int(self.y) - 6, int(38 * pct), 4)) # ══════════════════════════════════════════════════════════ # VELOCITY TRAIL # ══════════════════════════════════════════════════════════ trail = [] # list of (x, y, age) def update_trail(player): trail.append([player.x + player.W/2, player.y + player.H/2, 1.0]) for t in trail: t[2] -= 0.04 trail[:] = [t for t in trail if t[2] > 0] def draw_trail(surf): for t in trail: alpha = int(t[2] * 120) r = int(t[2] * 5) if r > 0: s = pygame.Surface((r*2, r*2), pygame.SRCALPHA) pygame.draw.circle(s, (100, 160, 255, alpha), (r, r), r) surf.blit(s, (int(t[0])-r, int(t[1])-r)) # ══════════════════════════════════════════════════════════ # MAIN # ══════════════════════════════════════════════════════════ player = Player() gravity_val = GRAVITY_DEFAULT gravity_on = True show_debug = True t_global = 0.0 while True: dt = clock.tick(FPS) / 1000.0 t_global += dt for event in pygame.event.get(): if event.type == pygame.QUIT: pygame.quit(); sys.exit() if event.type == pygame.KEYDOWN: if event.key == pygame.K_ESCAPE: pygame.quit(); sys.exit() if event.key == pygame.K_r: player.reset(); trail.clear() if event.key == pygame.K_g: gravity_on = not gravity_on if event.key in (pygame.K_EQUALS, pygame.K_PLUS): gravity_val = min(2400, gravity_val + 100) if event.key == pygame.K_MINUS: gravity_val = max(100, gravity_val - 100) if event.key == pygame.K_F1: show_debug = not show_debug # Register jump buffer on keydown if event.key == pygame.K_SPACE: player.jump_buffer = JUMP_BUFFER_FRAMES player.update(dt, gravity_val, gravity_on) update_trail(player) # ── DRAW ───────────────────────────────────────────────── screen.fill(DARK_BG) # Background grid for gx in range(0, WIDTH, 80): pygame.draw.line(screen, (16, 16, 26), (gx, 0), (gx, HEIGHT)) for gy in range(0, HEIGHT, 80): pygame.draw.line(screen, (16, 16, 26), (0, gy), (WIDTH, gy)) draw_trail(screen) draw_platforms(screen) if show_debug: player.draw_debug(screen) player.draw(screen) # ── Physics Debug Panel ─────────────────────────────────── panel_w = 280 px = WIDTH - panel_w - 10 py = 10 ph = 380 pygame.draw.rect(screen, (12, 12, 22), (px, py, panel_w, ph), border_radius=8) pygame.draw.rect(screen, GRAY, (px, py, panel_w, ph), 1, border_radius=8) blit(screen, "PHYSICS DEBUG", (px + 10, py + 10), CYAN, F_LG) pygame.draw.line(screen, GRAY, (px + 10, py + 36), (px + panel_w - 10, py + 36), 1) rows = [ ("vx", f"{player.vx:+.1f} px/s", BLUE, player.vx, -MOVE_SPEED, MOVE_SPEED), ("vy", f"{player.vy:+.1f} px/s", GREEN, player.vy, JUMP_VELOCITY, TERMINAL_VEL), ("gravity", f"{gravity_val:.0f} px/s²", YELLOW, gravity_val, 100, 2400), ("coyote", f"{player.coyote_timer} / {COYOTE_FRAMES} fr", ORANGE, player.coyote_timer, 0, COYOTE_FRAMES), ("jump buf", f"{player.jump_buffer} / {JUMP_BUFFER_FRAMES} fr", CYAN, player.jump_buffer, 0, JUMP_BUFFER_FRAMES), ] for i, (label, val_txt, color, val, vmin, vmax) in enumerate(rows): ry = py + 48 + i * 54 blit(screen, label, (px + 10, ry), GRAY_LT, F_SM) blit(screen, val_txt, (px + 80, ry), color, F_SM) bar(screen, px + 10, ry + 16, panel_w - 24, 12, val, vmin, vmax, color) # Flags fy = py + 48 + len(rows) * 54 flags = [ ("on_ground", player.on_ground, GREEN), ("jumping", player.jumping, BLUE_LT), ("gravity_on", gravity_on, YELLOW), ] for i, (name, state, color) in enumerate(flags): fx = px + 10 + i * 86 col_bg = color if state else GRAY pygame.draw.rect(screen, col_bg, (fx, fy, 78, 22), 0 if state else 1, border_radius=4) blit(screen, name[:8], (fx + 3, fy + 4), BLACK if state else GRAY_LT, F_SM) # Counters cy2 = fy + 32 blit(screen, f"Jumps: {player.jumps_done}", (px + 10, cy2), WHITE, F_SM) blit(screen, f"Coyote: {player.coyote_used}", (px + 10, cy2 + 16), ORANGE, F_SM) blit(screen, f"Max vy: {player.max_vy:.0f}", (px + 10, cy2 + 32), GREEN, F_SM) # ── Controls HUD ───────────────────────────────────────── hud_y = HEIGHT - 52 pygame.draw.rect(screen, (10, 10, 18), (0, hud_y, WIDTH, 52)) pygame.draw.line(screen, GRAY, (0, hud_y), (WIDTH, hud_y), 1) ctrl = [ "A/D: move", "SPACE: jump (hold=higher)", "G: gravity", "+/-: gravity strength", "F1: debug", "R: reset | ESC: quit", ] for i, c in enumerate(ctrl): col2 = i % 2 row2 = i // 2 blit(screen, c, (20 + col2 * 320, hud_y + 8 + row2 * 18), GRAY, F_SM) # Physics formula display blit(screen, "vy += gravity × dt | y += vy × dt | vx × friction", (20, hud_y + 36), GRAY_LT, F_SM) pygame.display.flip()