examples/hello.c


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/* A CPU-rendered window. Build instructions: docs/getting-started.md. */
#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);
            }
        }
        yasl_cpu_present(surface);
    }
    yasl_shutdown();
    return surface ? 0 : 1;
}