Add example

3 files changed, 109 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index 8990dd0..488245d 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ CFLAGS += -std=c99 -Wall -Wextra -Wpedantic
 
 include config.mk
 
-BINS = dump
+BINS = dump example
 
 all: ${BINS}
 
@@ -11,7 +11,7 @@ ${BINS}: cards.o
 .o:
 	${CC} ${LDFLAGS} $< cards.o ${LDLIBS} -o $@
 
-cards.o dump.o: cards.h
+cards.o dump.o example.o: cards.h
 
 clean:
 	rm -f ${BINS} *.o *.bmp
diff --git a/cards.3 b/cards.3
index b4dd61d..26c142c 100644
--- a/cards.3
+++ b/cards.3
@@ -183,6 +183,10 @@ of the files
 and
 .Pa SOL.EXE .
 .
+.Sh EXAMPLES
+See
+.Pa example.c .
+.
 .Sh ERRORS
 Error messages are set with
 .Fn SDL_SetError
diff --git a/example.c b/example.c
new file mode 100644
index 0000000..8790d65
--- /dev/null
+++ b/example.c
@@ -0,0 +1,103 @@
+/* Copyright (C) 2019  C. McEnroe <june@causal.agency>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <SDL.h>
+
+#include "cards.h"
+
+static void err(const char *title) {
+	int error = SDL_ShowSimpleMessageBox(
+		SDL_MESSAGEBOX_ERROR, title, SDL_GetError(), NULL
+	);
+	if (error) fprintf(stderr, "%s\n", SDL_GetError());
+	SDL_Quit();
+	exit(EXIT_FAILURE);
+}
+
+enum {
+	MarginX = 11,
+	MarginY = 6,
+	DeltaX = 14,
+	DeltaY = 6 + Cards_CardHeight,
+	WindowWidth = MarginX + 12 * DeltaX + Cards_CardWidth + MarginX,
+	WindowHeight = MarginY + 4 * DeltaY,
+};
+
+int main(void) {
+	if (SDL_Init(SDL_INIT_VIDEO) < 0) err("SDL_Init");
+
+	struct SDL_RWops *rw = SDL_RWFromFile("CARDS.DLL", "rb");
+	if (!rw) err("SDL_RWFromFile");
+
+	SDL_Surface *surfaces[Cards_CardCount];
+	int error = Cards_LoadCards(
+		surfaces, Cards_CardCount,
+		rw, Cards_ColorKey | Cards_AlphaCorners | Cards_BlackBorders
+	);
+	if (error) err("Cards_LoadCards");
+	SDL_RWclose(rw);
+
+	SDL_Window *window;
+	SDL_Renderer *render;
+	error = SDL_CreateWindowAndRenderer(
+		WindowWidth, WindowHeight, SDL_WINDOW_ALLOW_HIGHDPI,
+		&window, &render
+	);
+	if (error) err("SDL_CreateWindowAndRenderer");
+	SDL_SetWindowTitle(window, "Cards Example");
+
+	SDL_RenderSetIntegerScale(render, SDL_TRUE);
+	SDL_RenderSetLogicalSize(render, WindowWidth, WindowHeight);
+
+	SDL_Texture *textures[Cards_CardCount];
+	for (int i = 0; i < Cards_CardCount; ++i) {
+		textures[i] = NULL;
+		if (!surfaces[i]) continue;
+		textures[i] = SDL_CreateTextureFromSurface(render, surfaces[i]);
+		if (!textures[i]) err("SDL_CreateTextureFromSurface");
+		SDL_FreeSurface(surfaces[i]);
+	}
+
+	SDL_Rect rects[Cards_CardCount] = {0};
+	for (int i = 1; i <= 52; ++i) {
+		rects[i].x = MarginX + (i - 1) % 13 * DeltaX;
+		rects[i].y = MarginY + (i - 1) / 13 * DeltaY;
+		rects[i].w = Cards_CardWidth;
+		rects[i].h = Cards_CardHeight;
+	}
+
+	for (;;) {
+		SDL_SetRenderDrawColor(render, 0x00, 0xAA, 0x55, 0xFF);
+		SDL_RenderClear(render);
+		for (int i = 0; i < Cards_CardCount; ++i) {
+			if (!rects[i].w) continue;
+			SDL_RenderCopy(render, textures[i], NULL, &rects[i]);
+		}
+		SDL_RenderPresent(render);
+
+		SDL_Event event;
+		for (;;) {
+			SDL_WaitEvent(&event);
+			if (event.type == SDL_QUIT) goto quit;
+		}
+	}
+
+quit:
+	SDL_Quit();
+}