Function DrawComposite

deps/SDL2/test/testrendertarget.c:98–179

}

SDL_bool
DrawComposite(DrawState *s)
{
    SDL_Rect viewport, R;
    SDL_Texture *target;

    static SDL_bool blend_tested = SDL_FALSE;
    if (!blend_tested) {
        SDL_Texture *A, *B;
        Uint32 P;

        A = SDL_CreateTexture(s->renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, 1, 1);
        SDL_SetTextureBlendMode(A, SDL_BLENDMODE_BLEND);

        B = SDL_CreateTexture(s->renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, 1, 1);
        SDL_SetTextureBlendMode(B, SDL_BLENDMODE_BLEND);

        SDL_SetRenderTarget(s->renderer, A);
        SDL_SetRenderDrawColor(s->renderer, 0x00, 0x00, 0x00, 0x80);
        SDL_RenderFillRect(s->renderer, NULL);

        SDL_SetRenderTarget(s->renderer, B);
        SDL_SetRenderDrawColor(s->renderer, 0x00, 0x00, 0x00, 0x00);
        SDL_RenderFillRect(s->renderer, NULL);
        SDL_RenderCopy(s->renderer, A, NULL, NULL);
        SDL_RenderReadPixels(s->renderer, NULL, SDL_PIXELFORMAT_ARGB8888, &P, sizeof(P));

        SDL_Log("Blended pixel: 0x%8.8X\n", P);

        SDL_DestroyTexture(A);
        SDL_DestroyTexture(B);
        blend_tested = SDL_TRUE;
    }

    SDL_RenderGetViewport(s->renderer, &viewport);

    target = SDL_CreateTexture(s->renderer, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, viewport.w, viewport.h);
    SDL_SetTextureBlendMode(target, SDL_BLENDMODE_BLEND);
    SDL_SetRenderTarget(s->renderer, target);

    /* Draw the background.
       This is solid black so when the sprite is copied to it, any per-pixel alpha will be blended through.
     */
    SDL_SetRenderDrawColor(s->renderer, 0x00, 0x00, 0x00, 0x00);
    SDL_RenderFillRect(s->renderer, NULL);

    /* Scale and draw the sprite */
    s->sprite_rect.w += s->scale_direction;
    s->sprite_rect.h += s->scale_direction;
    if (s->scale_direction > 0) {
        if (s->sprite_rect.w >= viewport.w || s->sprite_rect.h >= viewport.h) {
            s->scale_direction = -1;
        }
    } else {
        if (s->sprite_rect.w <= 1 || s->sprite_rect.h <= 1) {
            s->scale_direction = 1;
        }
    }