Redefine public and rendering APIs with explicit contracts

1 files changed, 40 insertions, 16 deletions

diff --git a/examples/hello.c b/examples/hello.c
index 9e324a6..054051d 100644
--- a/examples/hello.c
+++ b/examples/hello.c
@@ -1,26 +1,50 @@
-/* A CPU-rendered window. Build instructions: docs/getting-started.md. */
+/* A CPU-rendered window. */
 #include <yasl/yasl.h>
 #include <yasl/cpu.h>
 
 int main(void)
 {
-    yasl_surface *surface = yasl_surface_create("Hello YASL", 640, 480, YASL_SURFACE_CPU);
-    yasl_event event;
-    while (surface && yasl_wait_event(&event, -1) >= 0 &&
-           event.type != YASL_EVENT_CLOSE && event.type != YASL_EVENT_QUIT) {
-        if (event.type != YASL_EVENT_REFRESH) continue;
-        int w, h;
-        uint32_t *pixels = yasl_cpu_pixels(surface, &w, &h);
-        for (int y = 0; pixels && y < h; y++) {
-            for (int x = 0; x < w; x++) {
-                /* Red grows rightward, green downward, blue fades; opaque premultiplied ARGB. */
-                uint32_t r = (uint32_t)(x * 255 / (w > 1 ? w - 1 : 1));
-                uint32_t g = (uint32_t)(y * 255 / (h > 1 ? h - 1 : 1));
-                pixels[(size_t)y * w + x] = 0xff000000 | r << 16 | g << 8 | (255 - r);
+    struct yasl_surface_options options = {
+        .title = "Hello YASL",
+        .width = 640,
+        .height = 480,
+        .type = YASL_SURFACE_CPU,
+    };
+    yasl_surface *surface = yasl_surface_create(&options);
+    if (!surface)
+        return 1;
+
+    int result = 0;
+    for (;;) {
+        yasl_event event;
+        if (yasl_wait_event(&event, -1) < 0) {
+            result = 1;
+            break;
+        }
+        if (event.type == YASL_EVENT_CLOSE || event.type == YASL_EVENT_QUIT)
+            break;
+        if (event.type != YASL_EVENT_REFRESH)
+            continue;
+
+        struct yasl_cpu_buffer buffer;
+        if (yasl_cpu_acquire(surface, &buffer) < 0) {
+            result = 1;
+            break;
+        }
+        for (int y = 0; y < buffer.height; y++) {
+            uint32_t *row = (uint32_t *)((unsigned char *)buffer.pixels + y * buffer.stride_bytes);
+            for (int x = 0; x < buffer.width; x++) {
+                /* Opaque premultiplied ARGB: red grows rightward, green downward. */
+                uint32_t r = (uint32_t)(x * 255 / (buffer.width > 1 ? buffer.width - 1 : 1));
+                uint32_t g = (uint32_t)(y * 255 / (buffer.height > 1 ? buffer.height - 1 : 1));
+                row[x] = 0xff000000 | r << 16 | g << 8 | (255 - r);
             }
         }
-        yasl_cpu_present(surface);
+        if (yasl_cpu_present(surface, &buffer) < 0) {
+            result = 1;
+            break;
+        }
     }
     yasl_shutdown();
-    return surface ? 0 : 1;
+    return result;
 }