testsprites2 of sdl

1。生成Texture需要指定window,否则程序选择当前的window(没有跟踪sdl源代码，猜想的)
2. 此例每个window都有2个不同的Texture,这样才能在不同的window中显示Texture
3。显示时用sdl_window + Texture代替了原来的sdl_overlay显示
从SDL_DisplayYUVOverlay函数来看，sdl_window显示时与overlay的方式应该是类似的

SDL_DisplayYUVOverlay(SDL_Overlay * overlay, SDL_Rect * dstrect)
{
    SDL_RenderCopy(overlay->hwdata->texture, NULL, dstrect);
    SDL_RenderPresent();
}

/* Simple program:  Move N sprites around on the screen as fast as possible */

#include
#include
#include

#include "common.h"

#define NUM_SPRITES 5
#define MAX_SPEED  1

static CommonState *state;
static int num_sprites;
static SDL_Texture **sprites;
static SDL_bool cycle_color;
static SDL_bool cycle_alpha;
static int cycle_direction = 1;
static int current_alpha = 0;
static int current_color = 0;
static SDL_Rect *positions;
static SDL_Rect *velocities;
static int sprite_w, sprite_h;
static SDL_BlendMode blendMode = SDL_BLENDMODE_MASK;
static SDL_TextureScaleMode scaleMode = SDL_TEXTURESCALEMODE_NONE;

/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void
quit(int rc)
{
    if (sprites) {
        SDL_free(sprites);
    }
    if (positions) {
        SDL_free(positions);
    }
    if (velocities) {
        SDL_free(velocities);
    }
    CommonQuit(state);
    exit(rc);
}

int
LoadSprite(char *file)
{
    int i;
    SDL_Surface **temp;

    /* Load the sprite image */
 temp = (SDL_Surface **)SDL_malloc(state->num_windows * sizeof(SDL_Surface));
    temp[0] = SDL_LoadBMP(file);
 temp[1] = SDL_LoadBMP("sample.bmp");
    if (*temp == NULL) {
        fprintf(stderr, "Couldn't load %s: %s", file, SDL_GetError());
        return (-1);
    }
    sprite_w = (*temp)->w;
    sprite_h = (*temp)->h;

    /* Set transparent pixel as the pixel at (0,0) */
    if ((*temp)->format->palette) {
        SDL_SetColorKey(temp[0], 1, *(Uint8 *) temp[0]->pixels);
  SDL_SetColorKey(temp[1], 1, *(Uint8 *) temp[1]->pixels);
    } else {
       /* switch (*temp->format->BitsPerPixel) {
        case 15:
            SDL_SetColorKey(temp, 1, (*(Uint16 *) temp->pixels) & 0x00007FFF);
            break;
        case 16:
            SDL_SetColorKey(temp, 1, *(Uint16 *) temp->pixels);
            break;
        case 24:
            SDL_SetColorKey(temp, 1, (*(Uint32 *) temp->pixels) & 0x00FFFFFF);
            break;
        case 32:
            SDL_SetColorKey(temp, 1, *(Uint32 *) temp->pixels);
            break;
        }*/
    }

    /* Create textures from the image */
    for (i = 0; i < state->num_windows*2; ++i)
 {
  int n = 0;
  if (i<2)
   n = 0;
  else
   n=1;

        SDL_SelectRenderer(state->windows[n]);
  n = i%2;

        sprites[i] = SDL_CreateTextureFromSurface(0, temp[n]);
        if (!sprites[i] )
  {
   SDL_SetColorKey(temp[n], 0, 0);
   sprites[i] = SDL_CreateTextureFromSurface(0, temp[n]);
  }
        if (!sprites[i])
  {
            fprintf(stderr, "Couldn't create texture: %s\n", SDL_GetError());
            SDL_FreeSurface(temp[n]);
            return (-1);
        }
        SDL_SetTextureBlendMode(sprites[i], blendMode);
        SDL_SetTextureScaleMode(sprites[i], scaleMode);
    }

 SDL_FreeSurface(temp[0]);
 SDL_FreeSurface(temp[1]);
 

    /* We're ready to roll. :) */
    return (0);
}

void
MoveSprites(SDL_Window * window, int k)
{
    int i, n;
    int window_w, window_h;
    SDL_Rect temp;
    SDL_Rect *position, *velocity;

    SDL_SelectRenderer(window);

    /* Query the sizes */
    SDL_GetWindowSize(window, &window_w, &window_h);

    /* Cycle the color and alpha, if desired */
   /* if (cycle_color) {
        current_color += cycle_direction;
        if (current_color < 0) {
            current_color = 0;
            cycle_direction = -cycle_direction;
        }
        if (current_color > 255) {
            current_color = 255;
            cycle_direction = -cycle_direction;
        }
        SDL_SetTextureColorMod(sprite, 255, (Uint8) current_color,
                               (Uint8) current_color);
    }
    if (cycle_alpha) {
        current_alpha += cycle_direction;
        if (current_alpha < 0) {
            current_alpha = 0;
            cycle_direction = -cycle_direction;
        }
        if (current_alpha > 255) {
            current_alpha = 255;
            cycle_direction = -cycle_direction;
        }
        SDL_SetTextureAlphaMod(sprite, (Uint8) current_alpha);
    }*/

    ///* Draw a gray background */
    SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
    SDL_RenderClear();

    ///* Test points */
    //SDL_SetRenderDrawColor(0xFF, 0x00, 0x00, 0xFF);
    //SDL_RenderDrawPoint(0, 0);
    //SDL_RenderDrawPoint(window_w-1, 0);
    //SDL_RenderDrawPoint(0, window_h-1);
    //SDL_RenderDrawPoint(window_w-1, window_h-1);

    ///* Test horizontal and vertical lines */
    //SDL_SetRenderDrawColor(0x00, 0xFF, 0x00, 0xFF);
    //SDL_RenderDrawLine(1, 0, window_w-2, 0);
    //SDL_RenderDrawLine(1, window_h-1, window_w-2, window_h-1);
    //SDL_RenderDrawLine(0, 1, 0, window_h-2);
    //SDL_RenderDrawLine(window_w-1, 1, window_w-1, window_h-2);

    ///* Test fill and copy */
    SDL_SetRenderDrawColor(0xFF, 0xFF, 0xFF, 0xFF);
    temp.x = 1;
    temp.y = 1;
    temp.w = sprite_w;
    temp.h = sprite_h;
    SDL_RenderFillRect(&temp);
    SDL_RenderCopy(sprites[2], NULL, &temp);
    temp.x = window_w-sprite_w-1;
    temp.y = 1;
    temp.w = sprite_w;
    temp.h = sprite_h;
    SDL_RenderFillRect(&temp);
    SDL_RenderCopy(sprites[3], NULL, &temp);
    temp.x = 1;
    temp.y = window_h-sprite_h-1;
    temp.w = sprite_w;
    temp.h = sprite_h;
    SDL_RenderFillRect(&temp);
    SDL_RenderCopy(sprites[0], NULL, &temp);
    temp.x = window_w-sprite_w-1;
    temp.y = window_h-sprite_h-1;
    temp.w = sprite_w;
    temp.h = sprite_h;
    SDL_RenderFillRect(&temp);
    SDL_RenderCopy(sprites[1], NULL, &temp);

    ///* Test diagonal lines */
    //SDL_SetRenderDrawColor(0x00, 0xFF, 0x00, 0xFF);
    //SDL_RenderDrawLine(sprite_w, sprite_h,
    //                   window_w-sprite_w-2, window_h-sprite_h-2);
    //SDL_RenderDrawLine(window_w-sprite_w-2, sprite_h,
    //                   sprite_w, window_h-sprite_h-2);

    /* Move the sprite, bounce at the wall, and draw */
    n = 0;
    for (i = 0; i < num_sprites; ++i) {
        position = &positions[i];
        velocity = &velocities[i];
        position->x += velocity->x;
        if ((position->x < 0) || (position->x >= (window_w - sprite_w))) {
            velocity->x = -velocity->x;
            position->x += velocity->x;
        }
        position->y += velocity->y;
        if ((position->y < 0) || (position->y >= (window_h - sprite_h))) {
            velocity->y = -velocity->y;
            position->y += velocity->y;
        }

        /* Blit the sprite onto the screen */
  n = SDL_RenderCopy(sprites[k*2 + i%2], NULL, position);
  printf("copy %d = %d\n", i, n);
    }

    /* Update the screen! */
    SDL_RenderPresent();
}

int
main(int argc, char *argv[])
{
    int i, done;
    SDL_Event event;
    Uint32 then, now, frames;

    /* Initialize parameters */
    num_sprites = NUM_SPRITES;

    /* Initialize test framework */
    state = CommonCreateState(argv, SDL_INIT_VIDEO);
    if (!state) {
        return 1;
    }
    for (i = 1; i < argc;) {
        int consumed;

        consumed = CommonArg(state, i);
        if (consumed == 0) {
            consumed = -1;
            if (SDL_strcasecmp(argv[i], "--blend") == 0) {
                if (argv[i + 1]) {
                    if (SDL_strcasecmp(argv[i + 1], "none") == 0) {
                        blendMode = SDL_BLENDMODE_NONE;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "mask") == 0) {
                        blendMode = SDL_BLENDMODE_MASK;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "blend") == 0) {
                        blendMode = SDL_BLENDMODE_BLEND;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "add") == 0) {
                        blendMode = SDL_BLENDMODE_ADD;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "mod") == 0) {
                        blendMode = SDL_BLENDMODE_MOD;
                        consumed = 2;
                    }
                }
            } else if (SDL_strcasecmp(argv[i], "--scale") == 0) {
                if (argv[i + 1]) {
                    if (SDL_strcasecmp(argv[i + 1], "none") == 0) {
                        scaleMode = SDL_TEXTURESCALEMODE_NONE;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "fast") == 0) {
                        scaleMode = SDL_TEXTURESCALEMODE_FAST;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "slow") == 0) {
                        scaleMode = SDL_TEXTURESCALEMODE_SLOW;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "best") == 0) {
                        scaleMode = SDL_TEXTURESCALEMODE_BEST;
                        consumed = 2;
                    }
                }
            } else if (SDL_strcasecmp(argv[i], "--cyclecolor") == 0) {
                cycle_color = SDL_TRUE;
                consumed = 1;
            } else if (SDL_strcasecmp(argv[i], "--cyclealpha") == 0) {
                cycle_alpha = SDL_TRUE;
                consumed = 1;
            } else if (SDL_isdigit(*argv[i])) {
                num_sprites = SDL_atoi(argv[i]);
                consumed = 1;
            }
        }
        if (consumed < 0) {
            fprintf(stderr,
                    "Usage: %s %s [--blend none|mask|blend|add|mod] [--scale none|fast|slow|best] [--cyclecolor] [--cyclealpha]\n",
                    argv[0], CommonUsage(state));
            quit(1);
        }
        i += consumed;
    }
    if (!CommonInit(state)) {
        quit(2);
    }

    /* Create the windows, initialize the renderers, and load the textures */
    sprites =
        (SDL_Texture **) SDL_malloc(2 * state->num_windows * sizeof(*sprites));
    if (!sprites) {
        fprintf(stderr, "Out of memory!\n");
        quit(2);
    }
    for (i = 0; i < state->num_windows; ++i) {
        SDL_SelectRenderer(state->windows[i]);
        SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
        SDL_RenderClear();
  SDL_SetWindowPosition(state->windows[i], i*25+20, i*50+70);
    }
    if (LoadSprite("icon.bmp") < 0) {
        quit(2);
    }

    /* Allocate memory for the sprite info */
    positions = (SDL_Rect *) SDL_malloc(num_sprites * sizeof(SDL_Rect));
    velocities = (SDL_Rect *) SDL_malloc(num_sprites * sizeof(SDL_Rect));
    if (!positions || !velocities) {
        fprintf(stderr, "Out of memory!\n");
        quit(2);
    }
    srand(time(NULL));
    if (scaleMode != SDL_TEXTURESCALEMODE_NONE) {
        sprite_w += sprite_w / 2;
        sprite_h += sprite_h / 2;
    }
    for (i = 0; i < num_sprites; ++i) {
        positions[i].x = rand() % (state->window_w - sprite_w);
        positions[i].y = rand() % (state->window_h - sprite_h);
        positions[i].w = sprite_w;
        positions[i].h = sprite_h;
        velocities[i].x = 0;
        velocities[i].y = 0;
        while (!velocities[i].x && !velocities[i].y) {
            velocities[i].x = (rand() % (MAX_SPEED * 2 + 1)) - MAX_SPEED;
            velocities[i].y = (rand() % (MAX_SPEED * 2 + 1)) - MAX_SPEED;
        }
    }

    /* Main render loop */
    frames = 0;
    then = SDL_GetTicks();
    done = 0;
    while (!done) {
        /* Check for events */
        ++frames;
        while (SDL_PollEvent(&event)) {
            CommonEvent(state, &event, &done);
            switch (event.type) {
            case SDL_WINDOWEVENT:
                switch (event.window.event) {
                case SDL_WINDOWEVENT_EXPOSED:
                    SDL_SelectRenderer(SDL_GetWindowFromID(event.window.windowID));
                    SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
                    SDL_RenderClear();
                    break;
                }
                break;
            default:
                break;
            }
        }
        for (i = 0; i < state->num_windows; ++i) {
   printf("window = %d ", i);
            MoveSprites(state->windows[i], i);
        }
  SDL_Delay(500);
    }

    /* Print out some timing information */
    now = SDL_GetTicks();
    if (now > then) {
        double fps = ((double) frames * 1000) / (now - then);
        printf("%2.2f frames per second\n", fps);
    }
    quit(0);
}

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