examples/hello.c


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/* A CPU-rendered window. */
#include <yasl/yasl.h>
#include <yasl/cpu.h>

int main(void)
{
    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);
            }
        }
        if (yasl_cpu_present(surface, &buffer) < 0) {
            result = 1;
            break;
        }
    }
    yasl_shutdown();
    return result;
}