From be5c7263406aef867501c7965bcced6a7e2898a6 Mon Sep 17 00:00:00 2001
From: quou <quou@disroot.org>
Date: Sun, 29 Sep 2024 16:39:31 +1000
Subject: animation, player movement, physics etc.

---
 .gitignore                      |   1 +
 1bitjam.c                       |  27 +++---
 Makefile                        |  36 ++++++-
 animation.c                     |   9 ++
 animation.h                     |  12 +++
 asset.c                         |   4 +
 asset.h                         |   1 +
 config.h                        |  32 ++++++-
 convanim.c                      |  79 ++++++++++++++++
 intermediate/guy.bmp            | Bin 394 -> 12426 bytes
 intermediate/guy_fall_left.anm  |   2 +
 intermediate/guy_fall_right.anm |   2 +
 intermediate/guy_idle_left.anm  |   2 +
 intermediate/guy_idle_right.anm |   2 +
 intermediate/guy_jump_left.anm  |   2 +
 intermediate/guy_jump_right.anm |   2 +
 intermediate/guy_run_left.anm   |   7 ++
 intermediate/guy_run_right.anm  |   7 ++
 intermediate/map.bmp            | Bin 0 -> 30858 bytes
 intermediate/mask.bmp           | Bin 0 -> 16522 bytes
 map.c                           |  68 ++++++++++++++
 map.h                           |  60 ++++++++++++
 obj.h                           |  32 +++++++
 physics.c                       | 204 ++++++++++++++++++++++++++++++++++++++++
 physics.h                       |  19 ++++
 plat.c                          |  12 +++
 plat.h                          |   4 +
 player.c                        | 132 ++++++++++++++++++++++++++
 rect.c                          |  16 ++++
 rect.h                          |   2 +
 render.h                        |   2 +-
 31 files changed, 751 insertions(+), 27 deletions(-)
 create mode 100644 animation.c
 create mode 100644 animation.h
 create mode 100644 convanim.c
 create mode 100644 intermediate/guy_fall_left.anm
 create mode 100644 intermediate/guy_fall_right.anm
 create mode 100644 intermediate/guy_idle_left.anm
 create mode 100644 intermediate/guy_idle_right.anm
 create mode 100644 intermediate/guy_jump_left.anm
 create mode 100644 intermediate/guy_jump_right.anm
 create mode 100644 intermediate/guy_run_left.anm
 create mode 100644 intermediate/guy_run_right.anm
 create mode 100644 intermediate/map.bmp
 create mode 100644 intermediate/mask.bmp
 create mode 100644 map.c
 create mode 100644 map.h
 create mode 100644 obj.h
 create mode 100644 physics.c
 create mode 100644 physics.h
 create mode 100644 player.c

diff --git a/.gitignore b/.gitignore
index 0a86950..40ef3ee 100644
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@ tags
 pack.h
 /data/
 /convimg
+/convanim
 /packassets
 /1bitjam
 /distrib
diff --git a/1bitjam.c b/1bitjam.c
index c2a84e1..619876e 100644
--- a/1bitjam.c
+++ b/1bitjam.c
@@ -1,7 +1,9 @@
 #include "asset.h"
 #include "config.h"
+#include "map.h"
 #include "maths.h"
 #include "memory.h"
+#include "obj.h"
 #include "plat.h"
 #include "rect.h"
 #include "render.h"
@@ -11,9 +13,8 @@ int entrypoint(int argc, const char** argv, Arena* m) {
 	App* a;
 	FPS f;
 	Renderer r;
-	Rect rect = { 0, 0, 32, 32 };
-	Rect rect2 = { 0, 0, 8, 8 };
-	int x = 0, y = 0;
+	Player player;
+	Map map;
 	(void)argc;
 	(void)argv;
 	init_maths();
@@ -25,25 +26,19 @@ int entrypoint(int argc, const char** argv, Arena* m) {
 	a = new_app(&h, game_name);
 	init_audio();
 	init_fps(&f, default_mpf);
+	generate_floor(&map, 0);
+	init_player(&player);
 	while (a->o) {
 		fps_begin(&f);
 		while (f.now >= f.next && a->o) {
 			app_begin(a);
+
+			update_player(&player, a, &map);
+
 			ren_begin(&r, a->fb, viewport_w, viewport_h);
 			ren_clear(&r);
-			if (a->btn_states[btn_left] & btn_state_pressed)
-				x--;
-			if (a->btn_states[btn_right] & btn_state_pressed)
-				x++;
-			if (a->btn_states[btn_up] & btn_state_pressed)
-				y--;
-			if (a->btn_states[btn_down] & btn_state_pressed)
-				y++;
-			if (a->btn_states[btn_shoot] & btn_state_just_pressed)
-				play_sound(30);
-			ren_text(&r, 30, 60, "Hello");
-			ren_map(&r, 10, 5, &rect, get_bitmap(asset_id_hello_img));
-			ren_map(&r, x, y, &rect2, get_bitmap(asset_id_guy_img));
+			render_map(&map, &r);
+			ren_player(&player, &r);
 			ren_end(&r);
 			app_end(a);
 			fps_update(&f);
diff --git a/Makefile b/Makefile
index 24a80cd..4c755b9 100644
--- a/Makefile
+++ b/Makefile
@@ -15,6 +15,7 @@ target = 1bitjam
 int_dir = intermediate
 data_dir = data
 convimg = convimg
+convanim = convanim
 packassets = packassets
 pack = pack.h
 
@@ -43,19 +44,35 @@ endif
 
 sources = \
 	1bitjam.c \
+	animation.c \
 	asset.c \
+	map.c \
 	maths.c \
 	memory.c \
+	physics.c \
 	plat.c \
+	player.c \
 	rect.c \
 	render.c \
 
 image_sources = \
 	$(int_dir)/guy.bmp \
-	$(int_dir)/hello.bmp
-
-objects = $(sources:%.c=%.o)
-images    = $(image_sources:$(int_dir)/%.bmp=$(data_dir)/%.img)
+	$(int_dir)/map.bmp \
+	$(int_dir)/mask.bmp
+
+anim_sources = \
+	$(int_dir)/guy_fall_left.anm \
+	$(int_dir)/guy_fall_right.anm \
+	$(int_dir)/guy_idle_left.anm \
+	$(int_dir)/guy_idle_right.anm \
+	$(int_dir)/guy_jump_left.anm \
+	$(int_dir)/guy_jump_right.anm \
+	$(int_dir)/guy_run_left.anm \
+	$(int_dir)/guy_run_right.anm \
+
+objects    = $(sources:%.c=%.o)
+images     = $(image_sources:$(int_dir)/%.bmp=$(data_dir)/%.img)
+animations = $(anim_sources:$(int_dir)/%.anm=$(data_dir)/%.anm)
 
 all: $(target) $(pack)
 
@@ -65,15 +82,22 @@ $(objects): %.o : %.c | $(pack)
 $(images): $(data_dir)/%.img : $(int_dir)/%.bmp | $(convimg) $(data_dir)
 	./$(convimg) $< $@
 
-$(pack): $(packassets) $(images)
+$(animations): $(data_dir)/%.anm : $(int_dir)/%.anm | $(convanim) $(data_dir)
+	./$(convanim) $< $@
+
+$(pack): $(packassets) $(images) $(animations)
 	./$(packassets) \
 		$(pack) \
 		$(data_dir) \
+		$(notdir $(animations)) \
 		$(notdir $(images))
 
 $(convimg): convimg.c
 	$(tool_compiler) convimg.c $(cflags) -o $@
 
+$(convanim): convanim.c
+	$(tool_compiler) convanim.c $(cflags) -o $@
+
 $(packassets): packassets.c
 	$(tool_compiler) packassets.c $(cflags) -o $@
 
@@ -89,5 +113,7 @@ clean:
 	rm $(pack)
 	rm -r $(data_dir)
 	rm $(target)
+	rm $(convimg)
+	rm $(convanim)
 
 -include $(sources:%.c=%.d)
diff --git a/animation.c b/animation.c
new file mode 100644
index 0000000..388e29d
--- /dev/null
+++ b/animation.c
@@ -0,0 +1,9 @@
+#include "animation.h"
+#include "rect.h"
+
+void update_anim(const Animation* a, int* f, Rect* r) {
+	f[0]++;
+	if (f[0] >= a->fc * a->s)
+		f[0] = 0;
+	*r = ((const Rect*)&a[1])[f[0] / a->s];
+}
diff --git a/animation.h b/animation.h
new file mode 100644
index 0000000..983fed8
--- /dev/null
+++ b/animation.h
@@ -0,0 +1,12 @@
+#ifndef animation_h
+#define animation_h
+
+struct Rect;
+
+typedef struct Animation {
+	int fc, s;
+} Animation;
+
+void update_anim(const Animation* a, int* f, struct Rect* r);
+
+#endif
diff --git a/asset.c b/asset.c
index 78085ec..31a6d8c 100644
--- a/asset.c
+++ b/asset.c
@@ -8,3 +8,7 @@ const unsigned char* get_asset(Asset_ID id) {
 const struct Bitmap* get_bitmap(Asset_ID id) {
 	return (const struct Bitmap*)get_asset(id);
 }
+
+const struct Animation* get_animation(Asset_ID id) {
+	return (const struct Animation*)get_asset(id);
+}
diff --git a/asset.h b/asset.h
index 74cf66b..09b631e 100644
--- a/asset.h
+++ b/asset.h
@@ -7,5 +7,6 @@
 
 const unsigned char* get_asset(Asset_ID id);
 const struct Bitmap* get_bitmap(Asset_ID id);
+const struct Animation* get_animation(Asset_ID id);
 
 #endif
diff --git a/config.h b/config.h
index 418e7f4..2fc4561 100644
--- a/config.h
+++ b/config.h
@@ -1,20 +1,42 @@
 #ifndef config_h
 #define config_h
 
+#include "maths.h"
+
 #define game_name "1bit Game Jam"
 
-#define memory_size (1024 * 8)
-#define app_memory_size (1024 * 4)
+#define memory_size (1024 * 32)
+#define app_memory_size (1024 * 16)
 
 #define max_pc_window_w 3000
 #define max_pc_window_h 3000
 
-#define viewport_w 128
-#define viewport_h 128
+#define viewport_w 320
+#define viewport_h 240
 #define default_scale 3
-#define default_mpf 50
+#define default_mpf 20
+
+#define map_w 20
+#define map_h 15
+#define map_tile_size 16
 
 #define audio_buffer_size 64
 #define audio_sample_rate 8000
 
+#define main_gravity (f1 / 4)
+#define main_gravity_ramp (f1)
+
+#define max_velocity (f1 * 4)
+
+#define player_move_force (f1 / 2)
+#define player_air_move_force (f1 / 10)
+#define player_max_vel 853
+#define player_friction (f1 / 4 + f1 / 20)
+#define player_stop_thresh 128
+#define player_jump_power (2 << fbits)
+#define player_jump_power_air (f1)
+#define player_shoot_cooldown 20
+#define player_attack_frames 10
+#define player_lunge_force (f1)
+
 #endif
diff --git a/convanim.c b/convanim.c
new file mode 100644
index 0000000..80a1b4a
--- /dev/null
+++ b/convanim.c
@@ -0,0 +1,79 @@
+#include "rect.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define max_rects 32
+
+const char* next_line(const char* line) {
+	const char* c;
+	for (c = line; *c != '\n'; c++) {
+		if (!*c) return 0;
+	}
+	return c + 1;
+}
+
+int line_len(const char* line) {
+	const char* c;
+	int r = 0;
+	for (c = line; *c && *c != '\n'; c++, r++);
+	return r;
+}
+
+int main(int argc, char** argv) {
+	FILE* infile;
+	const char* line;
+	char* src;
+	int size;
+	int speed;
+	Rect rects[max_rects];
+	Rect r;
+	int fc = 0;
+	if (argc < 3) {
+		fprintf(stderr, "Usage: %s infile outfile.\n", argv[0]);
+		return 1;
+	}
+	infile = fopen(argv[1], "rb");
+	if (!infile) {
+		fprintf(stderr, "Failed to open %s.\n", argv[1]);
+		return 2;
+	}
+	fseek(infile, 0, SEEK_END);
+	size = ftell(infile);
+	rewind(infile);
+	src = malloc(size + 1);
+	fread(src, 1, size, infile);
+	src[size] = 0;
+	fclose(infile);
+	line = src;
+	speed = (int)strtol(line, 0, 10);
+	line = next_line(line);
+	for (; line; line = next_line(line)) {
+		int ll = line_len(line);
+		char* line2 = malloc(ll + 1);
+		line2[ll] = 0; /* lmao */
+		memcpy(line2, line, ll);
+		if (sscanf(line,
+			"{%d,%d,%d,%d}", 
+			&r.x,
+			&r.y,
+			&r.w,
+			&r.h
+		) != 4) break;
+		rects[fc++] = r;
+	}
+	free(src);
+	{
+		FILE* outfile = fopen(argv[2], "wb");
+		if (!outfile) {
+			fprintf(stderr, "Failed to open %s.\n", argv[2]);
+			return 2;
+		}
+		fwrite(&fc,    1,  4,        outfile);
+		fwrite(&speed, 1,  4,        outfile);
+		fwrite(rects,  fc, sizeof r, outfile);
+		fclose(outfile);
+	}
+	return 0;
+}
diff --git a/intermediate/guy.bmp b/intermediate/guy.bmp
index 9a881e0..c7b155d 100644
Binary files a/intermediate/guy.bmp and b/intermediate/guy.bmp differ
diff --git a/intermediate/guy_fall_left.anm b/intermediate/guy_fall_left.anm
new file mode 100644
index 0000000..61e8acd
--- /dev/null
+++ b/intermediate/guy_fall_left.anm
@@ -0,0 +1,2 @@
+1
+{ 32, 16, 16, 16 }
diff --git a/intermediate/guy_fall_right.anm b/intermediate/guy_fall_right.anm
new file mode 100644
index 0000000..1919fdd
--- /dev/null
+++ b/intermediate/guy_fall_right.anm
@@ -0,0 +1,2 @@
+1
+{ 32, 0, 16, 16 }
diff --git a/intermediate/guy_idle_left.anm b/intermediate/guy_idle_left.anm
new file mode 100644
index 0000000..fe05177
--- /dev/null
+++ b/intermediate/guy_idle_left.anm
@@ -0,0 +1,2 @@
+1
+{ 0, 16, 16, 16 }
diff --git a/intermediate/guy_idle_right.anm b/intermediate/guy_idle_right.anm
new file mode 100644
index 0000000..86616a0
--- /dev/null
+++ b/intermediate/guy_idle_right.anm
@@ -0,0 +1,2 @@
+1
+{ 0, 0, 16, 16 }
diff --git a/intermediate/guy_jump_left.anm b/intermediate/guy_jump_left.anm
new file mode 100644
index 0000000..acec84e
--- /dev/null
+++ b/intermediate/guy_jump_left.anm
@@ -0,0 +1,2 @@
+1
+{ 16, 16, 16, 16 }
diff --git a/intermediate/guy_jump_right.anm b/intermediate/guy_jump_right.anm
new file mode 100644
index 0000000..633f46e
--- /dev/null
+++ b/intermediate/guy_jump_right.anm
@@ -0,0 +1,2 @@
+1
+{ 16, 0, 16, 16 }
diff --git a/intermediate/guy_run_left.anm b/intermediate/guy_run_left.anm
new file mode 100644
index 0000000..4d13a8e
--- /dev/null
+++ b/intermediate/guy_run_left.anm
@@ -0,0 +1,7 @@
+4
+{ 0,  16, 16, 16 }
+{ 16, 16, 16, 16 }
+{ 16, 16, 16, 16 }
+{ 0,  16, 16, 16 }
+{ 32, 16, 16, 16 }
+{ 32, 16, 16, 16 }
diff --git a/intermediate/guy_run_right.anm b/intermediate/guy_run_right.anm
new file mode 100644
index 0000000..b6098c5
--- /dev/null
+++ b/intermediate/guy_run_right.anm
@@ -0,0 +1,7 @@
+4
+{ 0,  0, 16, 16 }
+{ 16, 0, 16, 16 }
+{ 16, 0, 16, 16 }
+{ 0,  0, 16, 16 }
+{ 32, 0, 16, 16 }
+{ 32, 0, 16, 16 }
diff --git a/intermediate/map.bmp b/intermediate/map.bmp
new file mode 100644
index 0000000..13ee910
Binary files /dev/null and b/intermediate/map.bmp differ
diff --git a/intermediate/mask.bmp b/intermediate/mask.bmp
new file mode 100644
index 0000000..0363e3d
Binary files /dev/null and b/intermediate/mask.bmp differ
diff --git a/map.c b/map.c
new file mode 100644
index 0000000..855f636
--- /dev/null
+++ b/map.c
@@ -0,0 +1,68 @@
+#include "asset.h"
+#include "map.h"
+#include "rect.h"
+#include "render.h"
+
+#define null_tile 0xffff
+
+Rect tile_rects[] = {
+#define x(n, x, y) \
+	{ x, y, map_tile_size, map_tile_size },
+	tiles_xmacro
+#undef x
+};
+
+void generate_floor(Map* m, int seed) {
+	int e = map_w * map_h, i;
+	for (i = 0; i < e; i++) {
+		m->tiles[i] = null_tile;
+		m->collision[i] = 0;
+	}
+	e = map_w * (map_h - 1);
+	for (i = 0; i < map_w; i++) {
+		int idx = i + e;
+		m->tiles[idx] = tile_stone;
+		m->collision[idx] = 1;
+	}
+#define set(x, y) \
+	m->tiles[x + y * map_w] = tile_brick; \
+	m->collision[x + y * map_w] = 1;
+	set(0, 13);
+	set(0, 12);
+	set(0, 11);
+	set(1, 11);
+	set(2, 11);
+	set(3, 11);
+	set(4, 11);
+	set(19, 13);
+	set(19, 12);
+	set(19, 11);
+	set(19, 10);
+	set(19, 9);
+	set(19, 8);
+#undef set
+	m->tiles[18 + 13 * map_w] = tile_stone_ramp9;
+	m->collision[18 + 13 * map_w] = 6;
+	m->tiles[1 + 12 * map_w] = tile_stone_ramp13;
+	m->collision[1 + 12 * map_w] = 10;
+	m->tiles[2 + 12 * map_w] = tile_stone_ramp14;
+	m->collision[2 + 12 * map_w] = 11;
+}
+
+void render_map(const Map* m, Renderer* r) {
+	const Bitmap* tm = get_bitmap(asset_id_map_img);
+	int t = 0, x, y;
+	for (y = 0; y < map_h; y++) {
+		for (x = 0; x < map_w; x++, t++) {
+			int tile = m->tiles[t];
+			if (tile != null_tile)
+				ren_map(
+					r,
+					x * map_tile_size,
+					y * map_tile_size,
+					&tile_rects[tile],
+					tm
+				);
+		}
+	}
+}
diff --git a/map.h b/map.h
new file mode 100644
index 0000000..806de4d
--- /dev/null
+++ b/map.h
@@ -0,0 +1,60 @@
+#ifndef map_h_included
+#define map_h_included
+
+#include "config.h"
+
+struct Renderer;
+
+#define tiles_xmacro \
+	x(tile_stone,         0,   0)  \
+	x(tile_block1,        16,  0)  \
+	x(tile_block2,        32,  0)  \
+	x(tile_brick,         48,  0)  \
+	x(tile_ladder1,       64,  0)  \
+	x(tile_ladder2,       80,  0)  \
+	x(tile_stone_ramp1,   96,  0)  \
+	x(tile_stone_ramp2,  112,  0)  \
+	x(tile_stone_ramp3,  128,  0)  \
+	x(tile_stone_ramp4,  144,  0)  \
+	x(tile_stone_ramp5,    0,  16) \
+	x(tile_stone_ramp6,   16,  16) \
+	x(tile_stone_ramp7,   32,  16) \
+	x(tile_stone_ramp8,   48,  16) \
+	x(tile_stone_ramp9,   64,  16) \
+	x(tile_stone_ramp10,  80,  16) \
+	x(tile_stone_ramp11,  96,  16) \
+	x(tile_stone_ramp12, 112,  16) \
+	x(tile_stone_ramp13, 128,  16) \
+	x(tile_stone_ramp14, 144,  16) \
+	x(tile_brick_ramp5,    0,  32) \
+	x(tile_brick_ramp6,   16,  32) \
+	x(tile_brick_ramp7,   32,  32) \
+	x(tile_brick_ramp8,   48,  32) \
+	x(tile_brick_ramp9,   64,  32) \
+	x(tile_brick_ramp10,  80,  32) \
+	x(tile_brick_ramp11,  96,  32) \
+	x(tile_brick_ramp12, 112,  32) \
+	x(tile_brick_ramp13, 128,  32) \
+
+typedef enum {
+#define x(n, x, y) \
+	n,
+	tiles_xmacro
+#undef x
+	tile_count
+} Map_Tile;
+
+typedef struct Map {
+	unsigned short tiles[map_w * map_h];
+	unsigned short collision[map_w * map_h];
+	/* collision:
+	 * 0  = nothing
+	 * 1  = tile
+	 * >2 = mask
+	 */
+} Map;
+
+void generate_floor(Map* m, int seed);
+void render_map(const Map* m, struct Renderer* r);
+
+#endif
diff --git a/obj.h b/obj.h
new file mode 100644
index 0000000..9a331b7
--- /dev/null
+++ b/obj.h
@@ -0,0 +1,32 @@
+#ifndef obj_h
+#define obj_h
+
+#include "rect.h"
+
+struct App;
+struct Renderer;
+struct Map;
+
+typedef enum {
+	face_left,
+	face_right
+} Face;
+
+typedef struct {
+	int x, y, vx, vy;
+	int frame;
+	int anim;
+	int grounded, headbutted, on_ramp, jumping;
+	Face face;
+	Rect rect;
+} Player;
+
+void init_player(Player* p);
+void update_player(
+	Player* p,
+	struct App* app,
+	const struct Map* map
+);
+void ren_player(Player* p, struct Renderer* r);
+
+#endif
diff --git a/physics.c b/physics.c
new file mode 100644
index 0000000..b1a8db1
--- /dev/null
+++ b/physics.c
@@ -0,0 +1,204 @@
+#include "asset.h"
+#include "config.h"
+#include "map.h"
+#include "maths.h"
+#include "physics.h"
+#include "rect.h"
+#include "render.h"
+
+int test_bit(
+	unsigned* data,
+	int x,
+	int y,
+	int w
+) {
+	int idx = x + y * w;
+	return data[idx >> 5] & (1 << (idx & 0x1f));
+}
+
+static int solve_mask(
+	unsigned char t,
+	int* x,
+	int* y,
+	int* vy,
+	const Rect* col,
+	const Rect* r,
+	const Rect* tr,
+	int* od
+) {
+	int n, d = 0;
+	const Bitmap* b = get_bitmap(asset_id_mask_img);
+	unsigned* mp;
+	int xoff = 0;
+	int mx = r->x + r->w / 2;
+	int my = (r->y + r->h) - f1;
+	mx -= tr->x;
+	my -= tr->y;
+	mx >>= fbits;
+	my >>= fbits;
+	if (mx < 0 || mx >= map_tile_size)
+		return 0;
+	if ((n = my - map_tile_size) >= 0 && n < 4)
+		my = map_tile_size - 1;
+	mp = (unsigned*)&b[1];
+	xoff = (t & 0xf) * map_tile_size;
+	if (my >= map_tile_size) return 0;
+	if (my < 0 || *vy < 0) goto up;
+	if (test_bit(mp, mx + xoff, my, b->w)) {
+		d = -1;
+		my = map_tile_size - 1;
+	} else {
+up:
+		my = (r->y - tr->y) >> fbits;
+		if (my < 0) {
+			if (my >= -4) my = 0;
+			else          return 0;
+		}
+		if (my >= map_tile_size) return 0;
+		if (test_bit(mp, mx + xoff, my, b->w)) d = 1;
+		my = 0;
+	}
+	if (!d)                return 0;
+	if (d < 0 && *vy <= 0) return 0;
+	if (d > 0 && *vy >= 0) return 0;
+	for (
+		;
+			test_bit(mp, mx + xoff, my, b->w) &&
+			my >= 0 &&
+			my < map_tile_size;
+		my += d
+	);
+	if (d < 0) {
+		*y = (tr->y - (col->y + col->h));
+		*y += (my << fbits) + f1 * 2;
+	} else {
+		*y = (tr->y + tr->h) - col->y;
+		*y -= ((map_tile_size - my) << fbits);
+	}
+	*vy = 0;
+	*od = d;
+	return 1;
+}
+
+void update_body(
+	const struct Map* map,
+	int* x,
+	int* y,
+	int* vx,
+	int* vy,
+	int* grounded,
+	int* headbutted,
+	int* on_ramp,
+	const Rect* r
+) {
+	Rect rect = { 0 };
+	int ramp = 0, d;
+	rect.w = r->w;
+	rect.h = r->h;
+	if (grounded[0] < 3) {
+		*vx = (*vx << fbits) / (f1 + player_friction);
+	}
+	grounded[0]++;
+	headbutted[0] = 0;
+#define ittiles(expr) { \
+	int sx, sy, ex, ey, tx, ty; \
+	Rect tr; \
+	rect.x = *x + r->x; \
+	rect.y = *y + r->y; \
+	sx = (rect.x >> fbits) / map_tile_size; \
+	sy = (rect.y >> fbits) / map_tile_size; \
+	ex = ((rect.x + rect.w) >> fbits) / map_tile_size; \
+	ey = ((rect.y + rect.h) >> fbits) / map_tile_size; \
+	tr.w = map_tile_size << fbits; \
+	tr.h = map_tile_size << fbits; \
+	for (ty = sy; ty <= ey && ty < map_h; ty++) { \
+		for (tx = sx; tx <= ex && tx < map_w; tx++) { \
+			int tc = map->collision[tx + ty * map_w]; \
+			tr.x = (tx * map_tile_size) << fbits; \
+			tr.y = (ty * map_tile_size) << fbits; \
+			if (rects_overlap(&tr, &rect)) \
+				expr \
+		} \
+	}}
+	/* increase the gravity if i'm on a ramp, to
+	 * smoothly slide down instead of skipping */
+	*vy += main_gravity + main_gravity_ramp * (*on_ramp && *grounded < 3);
+	if (*vy) {
+		*y += *vy;
+		ittiles({
+			if (tc > 1) {
+				int id = tc - 2;
+				if (solve_mask(
+					id,
+					x,
+					y,
+					vy,
+					r,
+					&rect,
+					&tr,
+					&d
+				)) {
+					if (d < 0)
+						*grounded = 0;
+					else {
+						*headbutted = 1;
+					}
+					ramp = 1;
+				}
+			}
+		});
+		if (ramp) goto do_x;
+		ittiles({
+			if (tc == 1) {
+				if (*vy > 0) {
+					*y = tr.y - (r->y + r->h);
+					*vy = 0;
+					*grounded = 0;
+				} else if (*vy < 0) {
+					*y = (tr.y + tr.h) - r->y;
+					*vy = 0;
+					*headbutted = 1;
+				}
+			}
+		});
+	}
+do_x:
+	*on_ramp = ramp;
+	if (*vx) {
+		*x += *vx;
+		if (ramp) {
+			/* Handle the case where the body is at the top
+			 * of a ramp hitting into a block. */
+			ittiles({
+				if (tc == 1) {
+					int cy;
+					if (d < 0) cy = rect.y;
+					else cy = rect.y + rect.h;
+					if (*vx < 0 && point_rect_overlap(
+						&tr,
+						rect.x,
+						cy
+					)) *x = (tr.x + tr.w) - r->x;
+					if (*vx > 0 && point_rect_overlap(
+						&tr,
+						rect.x + rect.w,
+						cy
+					)) *x = tr.x - (r->x + r->w);
+				}
+			});
+			return;
+		}
+		ittiles({
+			if (tc == 1) {
+				if (*vx > 0) {
+					*x = tr.x - (r->x + r->w);
+					*vx = 0;
+				} else if (*vx < 0) {
+					*x = (tr.x + tr.w) - r->x;
+					*vx = 0;
+				}
+			}
+		});
+	}
+}
+
diff --git a/physics.h b/physics.h
new file mode 100644
index 0000000..7044996
--- /dev/null
+++ b/physics.h
@@ -0,0 +1,19 @@
+#ifndef physics_h
+#define physics_h
+
+struct Map;
+struct Rect;
+
+void update_body(
+	const struct Map* map,
+	int* x,
+	int* y,
+	int* vx,
+	int* vy,
+	int* grounded,
+	int* headbutted,
+	int* on_ramp,
+	const struct Rect* r
+);
+
+#endif
diff --git a/plat.c b/plat.c
index 7c5c9f8..cc351ff 100644
--- a/plat.c
+++ b/plat.c
@@ -3,6 +3,18 @@
 #include "memory.h"
 #include "plat.h"
 
+int btn_pressed(const App* a, Btn btn) {
+	return a->btn_states[btn] & btn_state_pressed;
+}
+
+int btn_just_pressed(const App* a, Btn btn) {
+	return a->btn_states[btn] & btn_state_just_pressed;
+}
+
+int btn_just_released(const App* a, Btn btn) {
+	return a->btn_states[btn] & btn_state_just_released;
+}
+
 #ifdef plat_posix
 #define _POSIX_SOURCE
 #define _GNU_SOURCE
diff --git a/plat.h b/plat.h
index 3c91ef6..32f17f6 100644
--- a/plat.h
+++ b/plat.h
@@ -81,4 +81,8 @@ void init_audio(void);
 void deinit_audio(void);
 void play_sound(int len);
 
+int btn_pressed(const App* a, Btn btn);
+int btn_just_pressed(const App* a, Btn btn);
+int btn_just_released(const App* a, Btn btn);
+
 #endif
diff --git a/player.c b/player.c
new file mode 100644
index 0000000..a99f40b
--- /dev/null
+++ b/player.c
@@ -0,0 +1,132 @@
+#include "animation.h"
+#include "asset.h"
+#include "map.h"
+#include "maths.h"
+#include "obj.h"
+#include "physics.h"
+#include "plat.h"
+#include "render.h"
+
+void init_player(Player* p) {
+	p->anim = asset_id_guy_run_right_anm;
+	p->x = 0;
+	p->y = 0;
+	p->vx = 0;
+	p->vy = 0;
+	p->frame = 0;
+	p->grounded = 0;
+	p->headbutted = 0;
+	p->on_ramp = 0;
+	p->jumping = 0;
+	p->face = face_right;
+}
+
+void update_player_anim(Player* p) {
+	const Animation* anim = get_animation(p->anim);
+	update_anim(anim, &p->frame, &p->rect);
+}
+
+void update_player_phys(Player* p, const Map* map) {
+	const Rect r = {
+		5  << fbits,
+		4  << fbits,
+		5  << fbits,
+		12 << fbits
+	};
+	update_body(
+		map,
+		&p->x,
+		&p->y,
+		&p->vx,
+		&p->vy,
+		&p->grounded,
+		&p->headbutted,
+		&p->on_ramp,
+		&r
+	);
+}
+
+void update_player_move(Player* p, const App* a) {
+	int grounded = p->grounded < 3;
+	int mf = player_move_force;
+	int nanim, moving, t;
+	int jumping = p->jumping;
+	Face* face = &p->face;
+	if (!grounded) {
+		mf = player_air_move_force;
+	}
+	if (btn_pressed(a, btn_left)) {
+		p->vx -= mf;
+		*face = face_left;
+	}
+	if (btn_pressed(a, btn_right)) {
+		p->vx += mf;
+		*face = face_right;
+	}
+	p->vx =
+		p->vx < -player_max_vel ? -player_max_vel:
+		p->vx >  player_max_vel ?  player_max_vel:
+		p->vx;
+	moving = absolute(p->vx);
+	moving = moving > player_stop_thresh;
+	if (p->grounded == 0 || p->headbutted) {
+		p->jumping = 0;
+	}
+	jumping = p->jumping;
+	if (jumping) {
+		if (p->grounded < 10 && btn_pressed(a, btn_jump)) {
+			t = absolute(p->vy + 1);
+			t = (f1 << fbits) / t;
+			p->vy -= (player_jump_power_air * t) >> fbits;
+		}
+		if (p->vy < 0 && btn_just_released(a, btn_jump)) {
+			p->vy += f1;
+			p->jumping = 0;
+		}
+	}
+	if (grounded && btn_just_pressed(a, btn_jump)) {
+		p->vy = -player_jump_power;
+		p->jumping = 1;
+		play_sound(500);
+	}
+	jumping = p->jumping;
+	nanim = p->anim;
+	switch (p->face) {
+		case face_left:
+			nanim =
+				grounded ?
+					moving ?
+						asset_id_guy_run_left_anm:
+						asset_id_guy_idle_left_anm:
+					p->vy < 0 ?
+						asset_id_guy_jump_left_anm:
+						asset_id_guy_fall_left_anm;
+			break;
+		case face_right:
+			nanim =
+				grounded ?
+					moving ?
+						asset_id_guy_run_right_anm:
+						asset_id_guy_idle_right_anm:
+					p->vy < 0 ?
+						asset_id_guy_jump_right_anm:
+						asset_id_guy_fall_right_anm;
+			break;
+		default: break;
+	}
+	if (nanim != p->anim) {
+		p->frame = 0;
+		p->anim = nanim;
+	}
+}
+
+void update_player(Player* p, App* app, const Map* map) {
+	update_player_move(p, app);
+	update_player_phys(p, map);
+	update_player_anim(p);
+}
+
+void ren_player(Player* p, struct Renderer* r) {
+	const Bitmap* b = get_bitmap(asset_id_guy_img);
+	ren_map(r, p->x >> fbits, p->y >> fbits, &p->rect, b);
+}
diff --git a/rect.c b/rect.c
index 69758c1..a35052d 100644
--- a/rect.c
+++ b/rect.c
@@ -1,5 +1,21 @@
 #include "rect.h"
 
+int rects_overlap(const Rect* a, const Rect* b) {
+	return
+		a->x + a->w > b->x &&
+		a->y + a->h > b->y &&
+		a->x < b->x + b->w &&
+		a->y < b->y + b->h;
+}
+
+int point_rect_overlap(const Rect* r, int px, int py) {
+	return
+		px >= r->x &&
+		py >= r->y &&
+		px <= r->x + r->w &&
+		py <= r->y + r->h;
+}
+
 Rect* rect_clip(Rect* r, const Rect* c) {
 	int n;
 	if ((n = c->x - r->x) > 0) {
diff --git a/rect.h b/rect.h
index 5c89aec..40f5e4e 100644
--- a/rect.h
+++ b/rect.h
@@ -5,6 +5,8 @@ typedef struct Rect {
 	int x, y, w, h;
 } Rect;
 
+int rects_overlap(const Rect* a, const Rect* b);
+int point_rect_overlap(const Rect* r, int px, int py);
 Rect* rect_clip(Rect* r, const Rect* c);
 Rect* rect_clipr(Rect* r, const int* c);
 Rect* rect_clips(Rect* r, Rect* s, const Rect* c);
diff --git a/render.h b/render.h
index 01391c5..2cb54b8 100644
--- a/render.h
+++ b/render.h
@@ -7,7 +7,7 @@ typedef struct Bitmap {
 	short w, h;
 } Bitmap;
 
-typedef struct {
+typedef struct Renderer {
 	unsigned* t;
 	int w, h;
 	int clip[4];
-- 
cgit v1.2.3-54-g00ecf