Added smooth pixel-perfect camera example + Small typo fix in examples_template.c (#1760)

* Typo fix

Changed "bsasic" to "basic" in the comments.

* Added pixel-perfect camera example

Added pixel-perfect camera example, both the .c file and the cover .png image. The example works with any resolution you want, as long as the ratio stays the same
(ex. 16:9, 4:3) ecc.

* Fixed Typecasts

Fixed compiler errors (implicit conversions)

* Precomputed rectangles, time-based movement and whitespace fix

Moved the source and destination rectangles for the renderTexture into their own variables, modified the animation to be time-based instead of frame-based, fixed the bug with whitespaces.

* Fixed spacing and added more consistency with sinf() and cosf()

* Fixed *= operator spacing

2 files changed, 136 insertions, 0 deletions

diff --git a/examples/core/core_2d_camera_smooth_pixelperfect.c b/examples/core/core_2d_camera_smooth_pixelperfect.c
new file mode 100644
index 00000000..3594c4ab
--- /dev/null
+++ b/examples/core/core_2d_camera_smooth_pixelperfect.c
@@ -0,0 +1,136 @@
+/*******************************************************************************************

+*

+*   raylib [core] example - smooth pixel-perfect camera

+*

+*   This example has been created using raylib 3.7 (www.raylib.com)

+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)

+*

+*   Example contributed by Giancamillo Alessandroni ([discord]NotManyIdeas#9972 - [github]NotManyIdeasDev) and

+*   reviewed by Ramon Santamaria (@raysan5)

+*

+*   Copyright (c) 2021 Giancamillo Alessandroni (NotManyIdeas#9972) and Ramon Santamaria (@raysan5)

+*

+********************************************************************************************/

+

+#include "raylib.h"

+#include <math.h>

+

+int main(void)

+{

+    // Initialization

+    //--------------------------------------------------------------------------------------

+    const int screenWidth = 800;

+    const int screenHeight = 450;

+

+    const int virualScreenWidth = 160;

+    const int virtualScreenHeight = 90;

+

+    const float virtualRatio = (float)screenWidth/(float)virualScreenWidth;

+

+    InitWindow(screenWidth, screenHeight, "raylib [core] example - smooth pixel-perfect camera");

+

+    Camera2D worldSpaceCamera = { 0 }; // Game world camera

+    worldSpaceCamera.zoom = 1.0f;

+

+    Camera2D screenSpaceCamera = { 0 }; //Smoothing camera

+    screenSpaceCamera.zoom = 1.0f;

+

+    RenderTexture2D renderTexture = LoadRenderTexture(virualScreenWidth, virtualScreenHeight); //This is where we'll draw all our objects.

+

+    Rectangle firstRectangle = { 70.0f, 35.0f, 20.0f, 20.0f };

+    Rectangle secondRectangle = { 90.0f, 55.0f, 30.0f, 10.0f };

+    Rectangle thirdRectangle = { 80.0f, 65.0f, 15.0f, 25.0f };

+

+    //The renderTexture's height is flipped (in the source Rectangle), due to OpenGL reasons.

+    Rectangle renderTextureSource = { 0.0f, 0.0f, (float)renderTexture.texture.width, (float)-renderTexture.texture.height };

+    Rectangle renderTextureDest = { -virtualRatio, -virtualRatio, screenWidth + (virtualRatio*2), screenHeight + (virtualRatio*2) };

+

+    Vector2 origin = { 0.0f, 0.0f };

+

+    float rotation = 0.0f;

+    float degreesPerSecond = 60.0f;

+

+    float cameraX = 0.0f;

+    float cameraY = 0.0f;

+

+    SetTargetFPS(60);

+    //--------------------------------------------------------------------------------------

+

+    // Main game loop

+    while (!WindowShouldClose())    // Detect window close button or ESC key

+    {

+        // Update

+        //----------------------------------------------------------------------------------

+        rotation += degreesPerSecond*GetFrameTime(); // Rotate the rectangles.

+

+        // Make the camera move to demonstrate the effect.

+        cameraX = (sinf(GetTime())*50.0f) - 10.0f;

+        cameraY = cosf(GetTime())*30.0f;

+

+        // Set the camera's target to the values computed above.

+        screenSpaceCamera.target = (Vector2){ cameraX, cameraY };

+

+        // Round worldCamera's X, keep the decimals on screenSpaceCamera.

+        if (screenSpaceCamera.target.x >= 1 || screenSpaceCamera.target.x <= -1)

+        {

+            worldSpaceCamera.target.x = (int)screenSpaceCamera.target.x;

+            screenSpaceCamera.target.x -= worldSpaceCamera.target.x;

+            screenSpaceCamera.target.x *= virtualRatio;

+        }

+

+        // Round worldCamera's Y, keep the decimals on screenSpaceCamera.

+        if (screenSpaceCamera.target.y >= 1 || screenSpaceCamera.target.y <= -1)

+        {

+            worldSpaceCamera.target.y = (int)screenSpaceCamera.target.y;

+            screenSpaceCamera.target.y -= worldSpaceCamera.target.y;

+            screenSpaceCamera.target.y *= virtualRatio;

+        }

+        //----------------------------------------------------------------------------------

+

+        // Draw

+        //----------------------------------------------------------------------------------

+        BeginDrawing();

+        ClearBackground(RED); // This is for debug purposes. If you see red, then you've probably done something wrong.

+

+        BeginTextureMode(renderTexture);

+        BeginMode2D(worldSpaceCamera);

+        ClearBackground(RAYWHITE); // This is the color you should see as background color.

+

+        // Draw the rectangles

+        DrawRectanglePro(firstRectangle, origin, rotation, BLACK);

+        DrawRectanglePro(secondRectangle, origin, -rotation, RED);

+        DrawRectanglePro(thirdRectangle, origin, rotation + 45.0f, BLUE);

+

+        EndMode2D();

+        EndTextureMode();

+

+        BeginMode2D(screenSpaceCamera);

+

+        // Draw the render texture with an offset of 1 worldSpace unit/pixel, so that the content behind the renderTexture is not shown.

+        DrawTexturePro(

+            renderTexture.texture,

+            renderTextureSource,

+            renderTextureDest,

+            origin,

+            0.0f,

+            WHITE

+        );

+

+        EndMode2D();

+

+        //Debug info

+        DrawText("Screen resolution: 800x450", 5, 0, 20, DARKBLUE);

+        DrawText("World resolution: 160x90", 5, 20, 20, DARKGREEN);

+        DrawFPS(screenWidth - 75, 0);

+        EndDrawing();

+        //----------------------------------------------------------------------------------

+    }

+

+    // De-Initialization

+    //--------------------------------------------------------------------------------------

+    UnloadRenderTexture(renderTexture); // RenderTexture unloading

+    CloseWindow();        // Close window and OpenGL context

+    //--------------------------------------------------------------------------------------

+

+    return 0;

+}
\ No newline at end of file
diff --git a/examples/core/core_2d_camera_smooth_pixelperfect.png b/examples/core/core_2d_camera_smooth_pixelperfect.png
new file mode 100644
index 00000000..aeac7944
--- /dev/null
+++ b/examples/core/core_2d_camera_smooth_pixelperfect.png