view test/testsprite2.c @ 2318:0c653886cce7

HandleEvent() returns done each time it is called. If done was set to 0 the program should quit, but because done is not checked until *all* events are handled a following event can reset done to 1 and prevent the program from terminating when told to. I fixed the while loop that handles events to check for the state of done after handling each event. That could leave some events unhandled when the program exits, but it ensures that the program will exit.
author Bob Pendleton <bob@pendleton.com>
date Wed, 20 Feb 2008 23:27:33 +0000
parents 926294b2bb4e
children e33ad7ebb7eb
line wrap: on
line source

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

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

#include "common.h"

#define NUM_SPRITES	100
#define MAX_SPEED 	1

static CommonState *state;
static int num_sprites;
static SDL_TextureID *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_TextureBlendMode blendMode = SDL_TEXTUREBLENDMODE_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_LoadBMP(file);
    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, SDL_SRCCOLORKEY, *(Uint8 *) temp->pixels);
    }

    /* Create textures from the image */
    for (i = 0; i < state->num_windows; ++i) {
        SDL_SelectRenderer(state->windows[i]);
        sprites[i] = SDL_CreateTextureFromSurface(0, temp);
        if (!sprites[i]) {
            fprintf(stderr, "Couldn't create texture: %s\n", SDL_GetError());
            SDL_FreeSurface(temp);
            return (-1);
        }
        SDL_SetTextureBlendMode(sprites[i], blendMode);
        SDL_SetTextureScaleMode(sprites[i], scaleMode);
    }
    SDL_FreeSurface(temp);

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

void
MoveSprites(SDL_WindowID window, SDL_TextureID sprite)
{
    int i, n;
    int window_w, window_h;
    SDL_Rect area, *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);
    }

    /* Move the sprite, bounce at the wall, and draw */
    n = 0;
    SDL_RenderFill(0xA0, 0xA0, 0xA0, 0xFF, NULL);
    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_w))) {
            velocity->y = -velocity->y;
            position->y += velocity->y;
        }

        /* Blit the sprite onto the screen */
        SDL_RenderCopy(sprite, NULL, position);
    }

    /* 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_TEXTUREBLENDMODE_NONE;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "mask") == 0) {
                        blendMode = SDL_TEXTUREBLENDMODE_MASK;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "blend") == 0) {
                        blendMode = SDL_TEXTUREBLENDMODE_BLEND;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "add") == 0) {
                        blendMode = SDL_TEXTUREBLENDMODE_ADD;
                        consumed = 2;
                    } else if (SDL_strcasecmp(argv[i + 1], "mod") == 0) {
                        blendMode = SDL_TEXTUREBLENDMODE_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_TextureID *) SDL_malloc(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_RenderFill(0xA0, 0xA0, 0xA0, 0xFF, NULL);
    }
    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(event.window.windowID);
                    SDL_RenderFill(0xA0, 0xA0, 0xA0, 0xFF, NULL);
                    break;
                }
                break;
            default:
                break;
            }
        }
        for (i = 0; i < state->num_windows; ++i) {
            MoveSprites(state->windows[i], sprites[i]);
        }
    }

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

/* vi: set ts=4 sw=4 expandtab: */