--- a/examples/CMakeLists.txt	Mon Oct 19 08:10:21 2020 +0200
+++ b/examples/CMakeLists.txt	Tue Oct 20 14:54:14 2020 +0200
@@ -73,6 +73,15 @@
 )
 
 molko_define_executable(
+	TARGET example-sprite
+	SOURCES example-sprite.c
+	FOLDER examples
+	ASSETS
+		${examples_SOURCE_DIR}/assets/sprites/people.png
+	LIBRARIES libui
+)
+
+molko_define_executable(
 	TARGET example-drawable
 	SOURCES example-drawable.c
 	FOLDER examples

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/example-sprite.c	Tue Oct 20 14:54:14 2020 +0200
@@ -0,0 +1,153 @@
+/*
+ * example-sprite.c -- example on how to use sprites
+ *
+ * Copyright (c) 2020 David Demelier <markand@malikania.fr>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdio.h>
+
+#include <core/clock.h>
+#include <core/core.h>
+#include <core/event.h>
+#include <core/image.h>
+#include <core/key.h>
+#include <core/painter.h>
+#include <core/panic.h>
+#include <core/image.h>
+#include <core/sprite.h>
+#include <core/texture.h>
+#include <core/util.h>
+#include <core/window.h>
+
+#include <ui/align.h>
+#include <ui/label.h>
+#include <ui/ui.h>
+
+#include <assets/sprites/people.h>
+
+#define W      1280
+#define H      720
+#define HEADER "Keys: <Left>/<Right> and <Up/Down> to select a column/row. Current: %u, %u (total %u/%u)"
+
+static char msg[512];
+static struct texture texture;
+static struct sprite sprite;
+static unsigned int row, column;
+
+static struct label help = {
+	.x = 10,
+	.y = 10,
+	.text = msg,
+	.flags = LABEL_FLAGS_SHADOW
+};
+
+static void
+changed(void)
+{
+	snprintf(msg, sizeof (msg), HEADER, column, row, sprite.ncols, sprite.nrows);
+}
+
+static void
+init(void)
+{
+	if (!core_init() || !ui_init())
+		panic();
+	if (!window_open("Example - Sprite", W, H))
+		panic();
+	if (!image_openmem(&texture, sprites_people, sizeof (sprites_people)))
+		panic();
+
+	sprite_init(&sprite, &texture, 48, 48);
+}
+
+static void
+run(void)
+{
+	struct clock clock = {0};
+	int x, y;
+
+	clock_start(&clock);
+	changed();
+
+	for (;;) {
+		union event ev;
+		unsigned int elapsed = clock_elapsed(&clock);
+
+		clock_start(&clock);
+
+		while (event_poll(&ev)) {
+			switch (ev.type) {
+			case EVENT_KEYDOWN:
+				switch (ev.key.key) {
+				case KEY_LEFT:
+					if (column > 0)
+						column--;
+					break;
+				case KEY_RIGHT:
+					if (column + 1 < sprite.ncols)
+						column++;
+					break;
+				case KEY_UP:
+					if (row > 0)
+						row--;
+					break;
+				case KEY_DOWN:
+					if (row + 1 < sprite.nrows)
+						row++;
+					break;
+				default:
+					break;
+				}
+
+				changed();
+				break;
+			case EVENT_QUIT:
+				return;
+			default:
+				break;
+			}
+		}
+
+		painter_set_color(0xebede9ff);
+		painter_clear();
+		align(ALIGN_CENTER, &x, &y, sprite.cellw, sprite.cellh, 0, 0, W, H);
+		sprite_draw(&sprite, row, column, x, y);
+		label_draw(&help);
+		painter_present();
+
+		if ((elapsed = clock_elapsed(&clock)) < 20)
+			delay(20 - elapsed);
+	}
+}
+
+static void
+quit(void)
+{
+	texture_finish(&texture);
+	window_finish();
+	ui_finish();
+	core_finish();
+}
+
+int
+main(int argc, char **argv)
+{
+	(void)argc;
+	(void)argv;
+
+	init();
+	run();
+	quit();
+}

--- a/libcore/core/sprite.c	Mon Oct 19 08:10:21 2020 +0200
+++ b/libcore/core/sprite.c	Tue Oct 20 14:54:14 2020 +0200
@@ -37,10 +37,21 @@
 	sprite->ncols = tex->w / cellw;
 }
 
+bool
+sprite_ok(const struct sprite *sprite)
+{
+	if (!sprite)
+		return false;
+
+	return texture_ok(sprite->texture) && sprite->cellw != 0 && sprite->cellh != 0;
+}
+
 void
 sprite_draw(struct sprite *sprite, unsigned int r, unsigned int c, int x, int y)
 {
-	assert(sprite);
+	assert(sprite_ok(sprite));
+	assert(r < sprite->nrows);
+	assert(c < sprite->ncols);
 
 	texture_scale(
 		sprite->texture,

--- a/libcore/core/sprite.h	Mon Oct 19 08:10:21 2020 +0200
+++ b/libcore/core/sprite.h	Tue Oct 20 14:54:14 2020 +0200
@@ -23,8 +23,28 @@
  * \file sprite.h
  * \brief Image sprites.
  * \ingroup drawing
+ *
+ * The sprite is a module to help rendering a large image that is split into
+ * individual parts. This improves memory usage as several images are loaded
+ * in a unique one instead of individual parts.
+ *
+ * Example of sprite.
+ *
+ * ```
+ * +---+---+---+
+ * | 0 | 1 | 2 |
+ * +---+---+---+
+ * | 3 | 4 | 5 |
+ * +---+---+---+
+ * ```
+ *
+ * If an image is designed like this grid, it contains three columns and 2 rows.
+ *
+ * \note The image may not contain space, margins or padding within each cell.
  */
 
+#include <stdbool.h>
+
 struct texture;
 
 /**
@@ -64,15 +84,25 @@
             unsigned int cellh);
 
 /**
+ * Tells if the sprite has a texture and isn't null sized.
+ *
+ * \param sprite the sprite to check (may be NULL)
+ * \return True if it is initialized correctly
+ */
+bool
+sprite_ok(const struct sprite *sprite);
+
+/**
  * Draw the sprite component from row `r' and column `c'.
  *
+ * \pre r < sprite->nrows
+ * \pre c < sprite->ncols
  * \pre sprite != NULL
  * \param sprite the sprite to draw
  * \param r the row number
  * \param c the column number
  * \param x the X destination
  * \param y the Y destination
- * \warning No bounds checking
  */
 void
 sprite_draw(struct sprite *sprite, unsigned int r, unsigned int c, int x, int y);