1 files changed, 130 insertions, 0 deletions
diff --git a/src/screen.c b/src/screen.c
new file mode 100644
index 0000000..5e23e0b
--- /dev/null
+++ b/src/screen.c
@@ -0,0 +1,130 @@
+#include "screen.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+
+void init_screen(Screen* screen, const char* title, uint16_t width, uint16_t height) {
+    screen->width = width;
+    screen->height = height;
+    size_t pixel_count = screen->width * screen->height;
+    screen->pixels = malloc(pixel_count * sizeof(uint32_t));
+    memset(screen->pixels, 0, pixel_count * sizeof(uint32_t));
+
+	SDL_Init(SDL_INIT_VIDEO);
+
+    screen->window =
+        SDL_CreateWindow(
+            title,
+            SDL_WINDOWPOS_CENTERED_DISPLAY(0),
+            SDL_WINDOWPOS_CENTERED_DISPLAY(0),
+            screen->width,
+            screen->height,
+            0
+        );
+
+    if (!screen->window) {
+		printf("fatal: failed to create sdl window\n");
+        exit(EXIT_FAILURE);
+	}
+
+    screen->renderer = 
+        SDL_CreateRenderer(
+            screen->window,
+            -1,
+            SDL_RENDERER_ACCELERATED
+            | SDL_RENDERER_PRESENTVSYNC
+        );
+
+    if (!screen->renderer) {
+        printf("fatal: failed to create sdl renderer\n");
+        exit(EXIT_FAILURE);
+    }
+
+    screen->texture =
+        SDL_CreateTexture(
+            screen->renderer,
+            SDL_PIXELFORMAT_RGBA8888,
+            SDL_TEXTUREACCESS_STREAMING,
+            screen->width,
+            screen->height
+        );
+    
+    if (!screen->texture) {
+        printf("fatal: failed to create window texture\n");
+        exit(EXIT_FAILURE);
+    }
+
+    screen->open = true;
+    screen->delta = 0;
+}
+
+static long last = 0;
+void poll_screen(Screen* screen) {
+    struct timespec spec;
+    clock_gettime(CLOCK_MONOTONIC, &spec);
+    long now = round(spec.tv_nsec / 1.0e6) + spec.tv_sec * 1000;
+    if (last == 0) {
+        screen->delta = 0;
+    } else {
+        screen->delta = (now - last) / 1000.0;
+    }
+    last = now;
+    
+    SDL_Event ev;
+    while (SDL_PollEvent(&ev)) {
+        switch (ev.type) {
+            case SDL_QUIT:
+                screen->open = false;
+                break;
+            default:
+                break;
+        }
+    }
+
+    screen->key_state = SDL_GetKeyboardState(NULL);
+}
+
+void draw_screen(Screen* screen) {
+    void *px;
+    int pitch;
+    SDL_LockTexture(screen->texture, NULL, &px, &pitch);
+    {
+        for (uint16_t y = 0; y < screen->height; y++) {
+            memcpy(
+                &((uint8_t*) px)[y * pitch],
+                &screen->pixels[y * screen->width],
+                screen->width * sizeof(uint32_t)
+            );
+        }
+    }
+    SDL_UnlockTexture(screen->texture);
+
+    SDL_SetRenderTarget(screen->renderer, NULL);
+    SDL_SetRenderDrawColor(screen->renderer, 0, 0, 0, 0xFF);
+    SDL_SetRenderDrawBlendMode(screen->renderer, SDL_BLENDMODE_NONE);
+
+    SDL_RenderClear(screen->renderer);
+    SDL_RenderCopyEx(
+        screen->renderer,
+        screen->texture,
+        NULL,
+        NULL,
+        0.0,
+        NULL,
+        SDL_FLIP_VERTICAL);
+
+    SDL_RenderCopy(screen->renderer, NULL, NULL, &((SDL_Rect) { 0, 0, 512, 512 }));
+    SDL_RenderPresent(screen->renderer);
+}
+
+void free_screen(Screen* screen) {
+    SDL_DestroyTexture(screen->texture);
+    SDL_DestroyRenderer(screen->renderer);
+	SDL_DestroyWindow(screen->window);
+}
+
+bool key_pressed(Screen* screen, SDL_Scancode code) {
+    return screen->key_state[code & 0xFFFF];    
+}