view test/testsprite2.c @ 4590:1ad70fb49fcb

Fix so many things that there is little place in this column to list them all but the result is that blending modes just work now for drawing primitives. Fixes involved: 1. Fix handling of alpha channel when SDL_BLENDMODE_NONE is set. 2. Make xrendercolor use floating-point values for color channels and then convert to 16 bit ints. 3. Fix handling of visuals in SDL_x11modes.c so that a 32 bit ARGB visual is used. 4. Fix the background pixel value in SDL_x11window.c so that the window background has an alpha value of 0xFF and not 0.
author Sunny Sachanandani <sunnysachanandani@gmail.com>
date Fri, 09 Jul 2010 21:36:41 +0530
parents 64ce267332c6
children dc26c37ad70e
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_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_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, 1, *(Uint8 *) temp->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; ++i) {
        SDL_SelectRenderer(state->windows[i]);
        sprites[i] = SDL_CreateTextureFromSurface(0, temp);
        if (!sprites[i]) {
		SDL_SetColorKey(temp, 0, 0);
		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_Window * window, SDL_Texture * sprite)
{
    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(sprite, 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(sprite, 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(sprite, 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(sprite, 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 */
        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_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(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();
    }
    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) {
            MoveSprites(state->windows[i], sprites[i]);
        }
    }

    /* 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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