Starting with SDL, can't load BMP :(

Apprentice

Posts: 6
Joined: 2007.01

Post: #1

Jan 16, 2007 — 04:18 PM

hi guys, I am starting on SDL ( using C ) . I followed some tutorials, but I haven't been able to load an image.

This is the code ( Using Xcode )

Code:

#include "stdlib.h"

#include "SDL/SDL.h"

int main(int argc, char *argv[])

{

    SDL_Surface *screen;    //This pointer will reference the backbuffer

    SDL_Surface *image;    //This pointer will reference our bitmap sprite

    SDL_Surface *temp;    //This pointer will temporarily reference our bitmap sprite

    SDL_Rect src, dest;    //These rectangles will describe the source and destination regions of our blit

    //We must first initialize the SDL video component, and check for success

    if (SDL_Init(SDL_INIT_VIDEO) != 0) {

        printf("Unable to initialize SDL: %s\n", SDL_GetError());

        return 1;

    }

    //When this program exits, SDL_Quit must be called

    atexit(SDL_Quit);

    //Set the video mode to fullscreen 640x480 with 16bit colour and double-buffering

    screen = SDL_SetVideoMode(640, 480, 16, SDL_DOUBLEBUF | SDL_FULLSCREEN);

    if (screen == NULL) {

        printf("Unable to set video mode: %s\n", SDL_GetError());

        return 1;

    }

    //Load the bitmap into a temporary surface, and check for success

    temp = SDL_LoadBMP("image.bmp");

    if (temp == NULL) {

        printf("Unable to load bitmap: %s\n", SDL_GetError());

        return 1;

    }

    //Convert the surface to the appropriate display format

    image = SDL_DisplayFormat(temp);

    //Release the temporary surface

    SDL_FreeSurface(temp);

    //Construct the source rectangle for our blit

    src.x = 0;

    src.y = 0;

    src.w = image->w;    //Use image->w to display the entire width of the image

    src.h = image->h;    //Use image->h to display the entire height of the image

    //Construct the destination rectangle for our blit

    dest.x = 100;        //Display the image at the (X,Y) coordinates (100,100)

    dest.y = 100;

    dest.w = image->w;    //Ensure the destination is large enough for the image's entire width/height

    dest.h = image->h;

    //Blit the image to the backbuffer

    SDL_BlitSurface(image, &src, screen, &dest);

    //Flip the backbuffer to the primary

    SDL_Flip(screen);

    //Wait for 2500ms (2.5 seconds) so we can see the image

    SDL_Delay(2500);

    //Release the surface

    SDL_FreeSurface(image);

    //Return success!

    return 0;

}

when I go for compile and run, the screen turns black, and no image loads... then I get

"[Session started at 2007-01-16 20:17:27 -0300.]
Unable to load bitmap: Couldn't open image.bmp

program has exited with status 1."

I placed the image.bmp in the same directory as main.c, that's inside the proyect folder... can someone help me ?

OneSadCookie

Luminary

Posts: 5,125
Joined: 2002.04

Post: #2

Jan 16, 2007 — 05:03 PM

You need to place the image next to the built application, for SDL.

ngoles

Apprentice

Posts: 6
Joined: 2007.01

Post: #3

Jan 16, 2007 — 07:13 PM

Oh, that's great, ill check it out tomorrow.

Quick question... if I want to build a self contained package ( so I don't use external folders for images and all that stuff... ) what should I do ?

maximile

Member

Posts: 281
Joined: 2006.05

Post: #4

Jan 16, 2007 — 07:43 PM

There's something you can change in SDLMain.c ... I can't remember what, but I think it's pretty obvious.

ngoles

Apprentice

Posts: 6
Joined: 2007.01

Post: #5

Jan 17, 2007 — 01:36 PM

Where should I place the SDLMain.c ???

I downloaded the extras pack from the SDL main URL, but I just installed the Xcode templates... don't have any idea of where to install the SDL main stuff

OneSadCookie

Luminary

Posts: 5,125
Joined: 2002.04

Post: #6

Jan 17, 2007 — 02:28 PM

Just include SDLMain.m and SDLMain.h in your project, in the usual manner.

ngoles

Apprentice

Posts: 6
Joined: 2007.01

Post: #7

Jan 17, 2007 — 02:55 PM

Oh ok , great, I think they come included in the templates

ngoles

Apprentice

Posts: 6
Joined: 2007.01

Post: #8

Jan 17, 2007 — 03:17 PM

Guys, about the initial post... I cant load the image

I am working with Xcode, and when I hit compile and run... all I get is a black screen, and then my error message that I added in

Code:

    //Load the bitmap into a temporary surface, and check for success

    temp = SDL_LoadBMP("image.bmp");

    if (temp == NULL) {

        printf("Unable to load bitmap: %s\n", SDL_GetError());

        return 1;

    }

I get

libro has exited with status 1.
[Session started at 2007-01-17 19:15:51 -0300.]
Unable to load bitmap: Couldn't open image.bmp

( all of this in Xcode... I don't know what is wrong... it must be something really stupid I think... I took the image.bmp to the project directory )

, if anyone can help me , it would be great!

I really want to get into this,

#########EDIT#######

Guys I managed to load the image specifying the whole path like this

Code:

//Load the bitmap into a temporary surface, and check for success

    temp = SDL_LoadBMP("/Volumes/MacHD/Users/USER/progra/SDL/libro/image.bmp");

    if (temp == NULL) {

        printf("Unable to load bitmap: %s\n", SDL_GetError());

        return 1;

    }

Is there an easier way of doing this instead of always specifying the whole path ??

Thanks!!!

OneSadCookie

Luminary

Posts: 5,125
Joined: 2002.04

Post: #9

Jan 17, 2007 — 04:07 PM

place the image next to the built application.

Somewhere like proga/SDL/libro/build/Debug, from memory. Take a look and find the actual application.

leRiCl

Member

Posts: 90
Joined: 2006.11

Post: #10

Jan 18, 2007 — 04:44 AM

O_o. All that code just to place an image on the screen? Crazy... I will be in there soon enough, though....

djork

Member

Posts: 37
Joined: 2006.08

Post: #11

Feb 21, 2007 — 11:25 AM

leRiCl Wrote:O_o. All that code just to place an image on the screen? Crazy... I will be in there soon enough, though....

You should see how much code it takes to set up an OpenGL context in Cocoa, load a PNG with libpng, and draw it from a Lua script. SDL is cake.

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