diff options
Diffstat (limited to 'trunk/example.c')
| -rw-r--r-- | trunk/example.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/trunk/example.c b/trunk/example.c index f2a7a86..7afd5a4 100644 --- a/trunk/example.c +++ b/trunk/example.c @@ -9,13 +9,12 @@ void sdl_draw_pixel(SDL_Surface* surface, uint32_t x, uint32_t y, uint32_t color { uint32_t* pixel = ((uint32_t*) (surface->pixels)) + (y * surface->pitch/4) + x; /* pretty sure SDL can do this, but can't figure out how */ + uint32_t bg_color = ((int) (x / 4.0) + ((int)(y / 4.0) % 2)) % 2 ? 0x99 : 0x66; + uint32_t alpha = color & 0x000000ff; - uint32_t r = alpha; - uint32_t g = alpha; - uint32_t b = alpha; - /*uint32_t r = ((color & 0xff000000) >> 24) * (alpha / 255.0); - uint32_t g = ((color & 0x00ff0000) >> 16) * (alpha / 255.0); - uint32_t b = ((color & 0x0000ff00) >> 8) * (alpha / 255.0);*/ + uint32_t r = (bg_color + (((color & 0xff000000) >> 24) - bg_color) * (alpha / 255.0)); + uint32_t g = (bg_color + (((color & 0x00ff0000) >> 16) - bg_color) * (alpha / 255.0)); + uint32_t b = (bg_color + (((color & 0x0000ff00) >> 8) - bg_color) * (alpha / 255.0)); uint32_t mapped_color = SDL_MapRGB(surface->format, r, g, b); *pixel = mapped_color; @@ -25,7 +24,7 @@ void sdl_blank(SDL_Surface* surface) { for (uint32_t y = 0; y < (uint32_t) surface->h; y++) { for (uint32_t x = 0; x < (uint32_t) surface->w; x++) { - sdl_draw_pixel(surface, x, y, (uint32_t) 0); + sdl_draw_pixel(surface, x, y, (uint32_t) ((int) (x / 4.0) + ((int)(y / 4.0) % 2)) % 2 ? 0x999999ff : 0x666666ff); } } } |