Begin implementing an SDL2 frontend

5 files changed, 92 insertions, 8 deletions

diff --git a/src/ahoy/emulator.c b/src/ahoy/emulator.c
index 1298ea0..b04e2ef 100644
--- a/src/ahoy/emulator.c
+++ b/src/ahoy/emulator.c
@@ -72,7 +72,7 @@ scrdrw(void)
 }
 
 void
-emulate(struct u8view prog)
+emuinit(struct u8view prog)
 {
 	struct timespec tp;
 
@@ -87,12 +87,14 @@ emulate(struct u8view prog)
 	if (clock_gettime(CLOCK_REALTIME, &tp) == -1)
 		die("clock_gettime");
 	srand(tp.tv_sec ^ tp.tv_nsec);
+}
 
-	for (;; PC += 2) {
-		uint16_t op = (mem[PC] << 8) | mem[PC + 1];
-		opexec(op);
-		scrdrw();
-	}
+void
+emutick(void)
+{
+	opexec((mem[PC] << 8) | mem[PC + 1]);
+	scrdrw();
+	PC += 2;
 }
 
 void
diff --git a/src/ahoy/emulator.h b/src/ahoy/emulator.h
index 31d596c..e9ba11f 100644
--- a/src/ahoy/emulator.h
+++ b/src/ahoy/emulator.h
@@ -3,6 +3,7 @@
 
 #include <mbstring.h>
 
-void emulate(struct u8view);
+void emuinit(struct u8view);
+void emutick(void);
 
 #endif /* !AHOY_AHOY_EMULATOR_H */
diff --git a/src/ahoy/gui.c b/src/ahoy/gui.c
new file mode 100644
index 0000000..1f3b748
--- /dev/null
+++ b/src/ahoy/gui.c
@@ -0,0 +1,71 @@
+#include <err.h>
+
+#include <SDL2/SDL.h>
+
+#include "cerr.h"
+
+#define SCR_SCALE 10
+#define SCR_WDTH  64
+#define SCR_HIGH  32
+
+#define diesx(fmt, ...) \
+	diex(fmt ": %s" __VA_OPT__(,) __VA_ARGS__, SDL_GetError())
+
+SDL_Window *win;
+SDL_Renderer *rndr;
+SDL_Texture *txtr;
+SDL_AudioDeviceID adev;
+unsigned long asmpcnt;
+struct {
+	void *p;
+	size_t sz;
+} abuf;
+
+void
+wininit(void)
+{
+	SDL_AudioSpec have;
+	SDL_AudioSpec want = {
+		.freq = 64 * 60,
+		.format = AUDIO_F32,
+		.channels = 1,
+		.samples = 64,
+	};
+
+	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) != 0)
+		diesx("failed to initialize SDL");
+
+	win = SDL_CreateWindow("Ahoy!", SDL_WINDOWPOS_CENTERED,
+	                       SDL_WINDOWPOS_CENTERED, SCR_WDTH * SCR_SCALE,
+	                       SCR_HIGH * SCR_SCALE, SDL_WINDOW_RESIZABLE);
+	if (!win)
+		diesx("failed to create window");
+
+	rndr = SDL_CreateRenderer(win, -1, SDL_RENDERER_ACCELERATED
+	                                 | SDL_RENDERER_PRESENTVSYNC);
+	if (!rndr)
+		diesx("failed to create renderer");
+
+	txtr = SDL_CreateTexture(rndr, SDL_PIXELFORMAT_RGBA8888,
+	                         SDL_TEXTUREACCESS_STREAMING, SCR_WDTH, SCR_HIGH);
+	if (!txtr)
+		diesx("failed to create texture");
+
+	adev = SDL_OpenAudioDevice(nullptr, 0, &want, &have,
+	                           SDL_AUDIO_ALLOW_FORMAT_CHANGE);
+	if (!adev) {
+		warnx("failed to open audio device: %s", SDL_GetError());
+		return;
+	}
+
+	asmpcnt = have.samples * have.channels;
+	abuf.sz = asmpcnt * 4;
+	if (!(abuf.p = malloc(abuf.sz)))
+		die("malloc");
+	SDL_PauseAudioDevice(adev, 0);
+}
+
+void
+winfree(void)
+{
+}
diff --git a/src/ahoy/gui.h b/src/ahoy/gui.h
new file mode 100644
index 0000000..251045e
--- /dev/null
+++ b/src/ahoy/gui.h
@@ -0,0 +1,7 @@
+#ifndef AHOY_AHOY_GUI_H
+#define AHOY_AHOY_GUI_H
+
+void wininit(void);
+void winfree(void);
+
+#endif /* !AHOY_AHOY_GUI_H */
diff --git a/src/ahoy/main.c b/src/ahoy/main.c
index ae7d5a1..dbc75f0 100644
--- a/src/ahoy/main.c
+++ b/src/ahoy/main.c
@@ -11,6 +11,7 @@
 
 #include "cerr.h"
 #include "emulator.h"
+#include "gui.h"
 #include "macros.h"
 
 [[noreturn]] static void usage(void);
@@ -100,6 +101,8 @@ run(int fd, const char *fn)
 		die("read: %s", fn);
 
 	free(buf);
-	emulate(u8strtou8(sb));
+	wininit();
+	emuinit(u8strtou8(sb));
 	u8strfree(sb);
+	winfree();
 }