add platform example

2 files changed, 221 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index 1329467..76ebcd4 100644
--- a/Makefile
+++ b/Makefile
@@ -22,7 +22,7 @@ PACKFLAGS ?=
 BIN = $(OBJDIR)/$(PROGRAM)$(EXE)
 PACKER = $(OBJDIR)/konpack$(EXE)
 MODELER = $(OBJDIR)/konmodel$(EXE)
-EXAMPLES = modelview sound ui
+EXAMPLES = modelview sound ui platform
 EXAMPLEBINS = $(EXAMPLES:%=$(OBJDIR)/%$(EXE))
 PACKFILE = $(OBJDIR)/data.kpk
 CORE = $(OBJDIR)/engine.o $(OBJDIR)/konwinlib.o $(OBJDIR)/konsofren.o \
diff --git a/examples/platform.c b/examples/platform.c
new file mode 100644
index 0000000..869e820
--- /dev/null
+++ b/examples/platform.c
@@ -0,0 +1,220 @@
+/*
+ * platform: a box that runs and jumps around a tilemap, and a ray that follows the mouse
+ *
+ * build:  ./build.sh -d -m tile,font obj/platform
+ * run:    obj/platform
+ *
+ * left and right or a and d run, space or up jumps. the line from the box to the mouse stops at the first solid tile
+ * the console is not needed, but with the debug module the grave key opens it and the variables gravity and jump are there
+ */
+
+#include <stdio.h>
+#include <math.h>
+
+#include "konprogram.h"
+#include "kontile.h"
+
+#if !defined(KON_MODULE_TILE) || !defined(KON_MODULE_FONT)
+#error "build with: ./build.sh -d -m tile,font obj/platform"
+#endif
+
+#define TILE 16
+#define COLUMNS 40
+#define ROWS 22
+#define STEP (1.0 / 120.0)
+
+#define COL_BACKGROUND 0xFF1B1826u
+#define COL_TILE       0xFF4A4468u
+#define COL_TILE_TOP   0xFF6B5F92u
+#define COL_PLAYER     0xFFF2A7C3u
+#define COL_RAY        0xFF8FD3C8u
+#define COL_HIT        0xFFF3DDA0u
+#define COL_DIM        0xFF9A93B3u
+
+static const char *level[ROWS] = {
+	"########################################",
+	"#......................................#",
+	"#......................................#",
+	"#......................................#",
+	"#......................................#",
+	"#..............#####...................#",
+	"#......................................#",
+	"#.........###..........................#",
+	"#......................................#",
+	"#.....................#####............#",
+	"#......................................#",
+	"#..####................................#",
+	"#......................................#",
+	"#..............####........#...........#",
+	"#.....................................##",
+	"#..........#.....................#######",
+	"#..........##..........................#",
+	"#..........###..................###....#",
+	"#..........####........................#",
+	"#.....#####............................#",
+	"#......................................#",
+	"########################################",
+};
+
+typedef struct state {
+	kon_tilemap_t map;
+	uint16_t tiles[COLUMNS * ROWS];
+	uint8_t solid[2];
+
+	kon_box2_t player;
+	kon_vec2_t velocity;
+	int onGround;
+	double leftover, coyote;
+	int left, right, jumpHeld;
+	float gravity, jump;
+
+	int mouseX, mouseY;
+	int rayHit;
+	kon_hit2_t hit;
+} state_t;
+
+/*** program ***/
+
+static int event(kon_program_t *program, const kon_event_t *ev, void *user)
+{
+	state_t *state = user;
+
+	if (ev->type == KON_EVENT_MOUSE_MOVE) {
+		kon_windowToGame(program->display, ev->mouseX, ev->mouseY, &state->mouseX, &state->mouseY);
+	} else if (ev->type == KON_EVENT_KEY_DOWN || ev->type == KON_EVENT_KEY_UP) {
+		int down = ev->type == KON_EVENT_KEY_DOWN;
+
+		if (ev->key == KON_KEY_LEFT || ev->key == KON_KEY_A) state->left = down;
+		else if (ev->key == KON_KEY_RIGHT || ev->key == KON_KEY_D) state->right = down;
+		else if (ev->key == KON_KEY_SPACE || ev->key == KON_KEY_UP) state->jumpHeld = down;
+		else return 0;
+	} else {
+		return 0;
+	}
+	return 1;
+}
+
+static void step(state_t *state, float dt)
+{
+	float run = (float)(state->right - state->left) * 120.0f;
+	int flags;
+
+	state->velocity.x += (run - state->velocity.x) * (state->onGround ? 18.0f : 8.0f) * dt;
+	state->velocity.y += state->gravity * dt;
+
+	if (state->coyote > 0.0) state->coyote -= dt;
+	if (state->jumpHeld && state->coyote > 0.0) {
+		state->velocity.y = -state->jump;
+		state->coyote = 0.0;
+	}
+	/* letting go early cuts the jump short */
+	if (!state->jumpHeld && state->velocity.y < -60.0f) state->velocity.y = -60.0f;
+
+	flags = kon_tilemapMove(&state->map, &state->player, state->velocity.x * dt, state->velocity.y * dt, state->solid, 2);
+
+	if (flags & (KON_HIT_LEFT | KON_HIT_RIGHT)) state->velocity.x = 0.0f;
+	if (flags & (KON_HIT_UP | KON_HIT_DOWN)) state->velocity.y = 0.0f;
+	state->onGround = (flags & KON_HIT_DOWN) != 0;
+	if (state->onGround) state->coyote = 0.08;
+}
+
+static void update(kon_program_t *program, double dt, void *user)
+{
+	state_t *state = user;
+	kon_vec2_t from = KON_VEC2(state->player.x + state->player.w * 0.5f, state->player.y + state->player.h * 0.5f);
+	kon_vec2_t dir = KON_VEC2((float)state->mouseX - from.x, (float)state->mouseY - from.y);
+	float length = kon_vec2Length(dir);
+	int row, column;
+
+	(void)program;
+	state->leftover += dt;
+	while (state->leftover >= STEP) {
+		step(state, (float)STEP);
+		state->leftover -= STEP;
+	}
+
+	/* the ray against every solid tile, nothing clever, the nearest one wins */
+	state->rayHit = 0;
+	if (length < 1.0f) return;
+	dir = kon_vec2Scale(dir, 1.0f / length);
+	for (row = 0; row < ROWS; row++) {
+		for (column = 0; column < COLUMNS; column++) {
+			kon_hit2_t hit;
+
+			if (!state->solid[kon_tilemapAt(&state->map, column, row)]) continue;
+			if (!kon_rayBox(from, dir, length, KON_BOX2(column * TILE, row * TILE, TILE, TILE), &hit)) continue;
+			if (!state->rayHit || hit.time < state->hit.time) {
+				state->hit = hit;
+				state->rayHit = 1;
+			}
+		}
+	}
+}
+
+static void draw(kon_program_t *program, kon_framebuffer_t *game, void *user)
+{
+	state_t *state = user;
+	int row, column, ex, ey;
+	int fromX = (int)(state->player.x + state->player.w * 0.5f), fromY = (int)(state->player.y + state->player.h * 0.5f);
+
+	kon_clearFramebuffer(game, COL_BACKGROUND);
+
+	for (row = 0; row < ROWS; row++) {
+		for (column = 0; column < COLUMNS; column++) {
+			if (!state->solid[kon_tilemapAt(&state->map, column, row)]) continue;
+			kon_fillRectangle(game, column * TILE, row * TILE, TILE, TILE, COL_TILE);
+			if (!state->solid[kon_tilemapAt(&state->map, column, row - 1)]) kon_fillRectangle(game, column * TILE, row * TILE, TILE, 2, COL_TILE_TOP);
+		}
+	}
+
+	ex = state->rayHit ? (int)state->hit.point.x : state->mouseX;
+	ey = state->rayHit ? (int)state->hit.point.y : state->mouseY;
+	kon_drawLine(game, fromX, fromY, ex, ey, COL_RAY);
+	if (state->rayHit) kon_fillCircle(game, ex, ey, 2, COL_HIT);
+
+	kon_fillRectangle(game, (int)state->player.x, (int)state->player.y, (int)state->player.w, (int)state->player.h, COL_PLAYER);
+
+	if (program->font) kon_drawText(game, program->font, 24, 40, "arrows or a d to run, space to jump", COL_DIM);
+}
+
+static int init(kon_program_t *program, void *user)
+{
+	state_t *state = user;
+	int row, column;
+
+	state->map.columns = COLUMNS;
+	state->map.rows = ROWS;
+	state->map.tileWidth = TILE;
+	state->map.tileHeight = TILE;
+	state->map.tiles = state->tiles;
+	state->solid[1] = 1;
+	for (row = 0; row < ROWS; row++) {
+		for (column = 0; column < COLUMNS; column++) state->tiles[row * COLUMNS + column] = level[row][column] == '#';
+	}
+
+	state->player = KON_BOX2(40, 280, 10, 14);
+	state->gravity = 700.0f;
+	state->jump = 260.0f;
+
+	kon_debugVar(program->debug, "gravity", KON_VAR_FLOAT, &state->gravity);
+	kon_debugVar(program->debug, "jump", KON_VAR_FLOAT, &state->jump);
+	return 1;
+}
+
+int main(void)
+{
+	state_t state = {0};
+	kon_programConfig_t config = {0};
+
+	config.title = "platform";
+	config.gameWidth = 640;
+	config.gameHeight = 352;
+	config.windowWidth = 1280;
+	config.windowHeight = 704;
+	config.user = &state;
+	config.init = init;
+	config.event = event;
+	config.update = update;
+	config.draw = draw;
+	return kon_programRun(&config);
+}