Scrolling background

[JeffM2501]

This is a code snippet that shows how to do an infinitely scrolling background by using a source rectangle that is larger that the source image to get repeats.

/*******************************************************************************************
*
*   raylib [core] example - Basic window
*
*   Welcome to raylib!
*
*   To test examples, just press F6 and execute raylib_compile_execute script
*   Note that compiled executable is placed in the same folder as .c file
*
*   You can find all basic examples on C:\raylib\raylib\examples folder or
*   raylib official webpage: www.raylib.com
*
*   Enjoy using raylib. :)
*
*   This example has been created using raylib 1.0 (www.raylib.com)
*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
*
*   Copyright (c) 2013-2016 Ramon Santamaria (@raysan5)
*
********************************************************************************************/

#include "raylib.h"

int main(void)
{
    // Initialization
    //--------------------------------------------------------------------------------------
    const int screenWidth = 800;
    const int screenHeight = 450;

    InitWindow(screenWidth, screenHeight, "raylib [core] example - basic window");

    Texture tx = LoadTexture("resources/raylib_logo.png");
    Vector2 offset = { 0,0 };

    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
    //--------------------------------------------------------------------------------------

    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        offset.x += GetFrameTime() * 100;
        offset.y -= GetFrameTime() * 100;

        // Draw
        //----------------------------------------------------------------------------------
        BeginDrawing();

            ClearBackground(RAYWHITE);

            DrawTexturePro(tx
                ,(Rectangle) { offset.x, offset.y, GetScreenWidth(), GetScreenHeight() }
                ,(Rectangle) {  0, 0, GetScreenWidth(), GetScreenHeight() }
                ,(Vector2) { 0, 0 }
                , 0
                , WHITE);

            DrawText("Congrats! You created your first window!", 190, 200, 20, RED);

        EndDrawing();
        //----------------------------------------------------------------------------------
    }

    // De-Initialization
    //--------------------------------------------------------------------------------------
    CloseWindow();        // Close window and OpenGL context
    //--------------------------------------------------------------------------------------

    return 0;
}

[rdthree]

Thanks, here is how I updated for a sideways scroll, when the source is smaller than the window and without tiling in the Y direction:

#include "raylib.h"

int main()
{
    //preamble
    const int windowW{600};
    const int windowH{380};
    float dt{0};     // for use with delta time between frames

    SetTargetFPS(60);
    InitWindow(windowW, windowH, "walk");

    //backgrounds
    Texture2D bg = LoadTexture("textures/far-buildings.png"); // 256 X 192
    Vector2 offset = {0, 0};
    Rectangle bgSrc = {offset.x, offset.y, bg.width, bg.height};
    Rectangle bgDest = {0, 0, windowW, windowH};

    while (!WindowShouldClose())
    {
        //start drawing
        BeginDrawing();
        ClearBackground(WHITE);

        dt = GetFrameTime();
        bgSrc.x += 200 * dt;

        DrawTexturePro(bg, bgSrc, bgDest, {0, 0}, 0, WHITE);

        DrawText(FormatText("dt: %f", dt), 3, windowH - 10, 10, GOLD);
        EndDrawing();
    }
    UnloadTexture(bg);
    CloseWindow();
}