Add agnes NES emulator (very slow).

Add -W <n> -H <n> width and height options to host-sdl

apps/agnes/src/agnes.h

@@ -0,0 +1,88 @@
+#include <zeptolibc/zeptolibc.h>
+/*
+SPDX-License-Identifier: MIT
+
+agnes
+https://http://github.com/kgabis/agnes
+Copyright (c) 2022 Krzysztof Gabis
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+#ifndef agnes_h
+#define agnes_h
+
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+#define AGNES_VERSION_MAJOR 0
+#define AGNES_VERSION_MINOR 2
+#define AGNES_VERSION_PATCH 0
+
+#define AGNES_VERSION_STRING "0.2.0"
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+enum {
+    AGNES_SCREEN_WIDTH = 256,
+    AGNES_SCREEN_HEIGHT = 240
+};
+
+typedef struct {
+    bool a;
+    bool b;
+    bool select;
+    bool start;
+    bool up;
+    bool down;
+    bool left;
+    bool right;
+} agnes_input_t;
+
+typedef struct {
+    uint8_t r;
+    uint8_t g;
+    uint8_t b;
+    uint8_t a;
+} agnes_color_t;
+
+typedef struct agnes agnes_t;
+typedef struct agnes_state agnes_state_t;
+
+agnes_t* agnes_make(void);
+void agnes_destroy(agnes_t *agn);
+bool agnes_load_ines_data(agnes_t *agnes, const void *data, size_t data_size);
+void agnes_set_input(agnes_t *agnes, const agnes_input_t *input_1, const agnes_input_t *input_2);
+size_t agnes_state_size(void);
+void agnes_dump_state(const agnes_t *agnes, agnes_state_t *out_res);
+bool agnes_restore_state(agnes_t *agnes, const agnes_state_t *state);
+bool agnes_tick(agnes_t *agnes, bool *out_new_frame);
+bool agnes_next_frame(agnes_t *agnes);
+
+agnes_color_t agnes_get_screen_pixel(const agnes_t *agnes, int x, int y);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* agnes_h */