官术网_书友最值得收藏!

Clearing the SDL renderer

After the initialization is complete, we will need to clear out the renderer. We can clear our renderer with any color we choose. To do this, we will make a call to the SDL_RenderDrawColor function:

SDL_SetRenderDrawColor( renderer, 0, 0, 0, 255 );
SDL_RenderClear( renderer );

That sets the drawing color for the renderer to black with full opacity. 0, 0, 0 are the RGB color values, and 255 is the alpha opacity. These numbers all range from 0 to 255, where 255 is the full color on the color spectrum. We set this up so that when we call the SDL_RenderClear function in the next line, it will clear the renderer with the color black. If we wanted the color to clear red instead of black, we would have to modify the call in the following way:

SDL_SetRenderDrawColor( renderer, 255, 0, 0, 255 );

That is not what we want, so we will not make that change. I just wanted to point out that we could clear the renderer with any color we like.

主站蜘蛛池模板: 固镇县| 简阳市| 武安市| 红原县| 简阳市| 湘阴县| 苍梧县| 万年县| 云南省| 大英县| 始兴县| 敦煌市| 冷水江市| 彭州市| 远安县| 浦城县| 靖宇县| 精河县| 茌平县| 兴隆县| 仁布县| 永兴县| 巨野县| 鲜城| 岑溪市| 平安县| 临清市| 重庆市| 称多县| 永新县| 荔波县| 高邮市| 灵山县| 安乡县| 县级市| 丹寨县| 固始县| 商丘市| 崇义县| 威海市| 沭阳县|