[cmake] Propagate Cocoa backend frameworks to consumers of static raylib on macOS (#6086)

* [cmake] Fix standalone configuration of examples project

Configuring examples/ as a standalone project (cd examples && cmake .)
failed with 'Unknown CMake command add_if_flag_compiles' and a missing
cmake_minimum_required() error on CMake 4.x.

- Add cmake_minimum_required(VERSION 3.22), matching the root project
- Include raylib's AddIfFlagCompiles helper via ../cmake
- Default PLATFORM to Desktop when not inherited from the raylib build

* [cmake] Propagate Cocoa backend frameworks to consumers of static raylib on macOS

Bundled GLFW links '-framework Cocoa/IOKit/QuartzCore' privately, and the
static-install export block removes glfw from the exported dependencies.
As a result the installed CMake package only carried OpenGL.framework,
and linking any consumer of libraylib.a failed with undefined Objective-C
symbols (_objc_retain etc.).

Append the three frameworks to the static install interface when the
bundled GLFW is used, so installed consumers get a complete link line.

* Gate macOS Cocoa framework propagation to the Desktop platform

examples/CMakeLists.txt

@@ -1,6 +1,18 @@
 # Setup the project and settings
+cmake_minimum_required(VERSION 3.22)
 project(examples)
 
+# Include raylib's cmake helper functions, so the examples can also be
+# configured standalone (`cd examples && cmake .`) and not only as part
+# of the raylib project.
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/../cmake")
+include(AddIfFlagCompiles)
+
+# Default to the Desktop platform when configured standalone.
+if (NOT DEFINED PLATFORM)
+    set(PLATFORM "Desktop" CACHE STRING "Platform to build examples for")
+endif ()
+
 # Directories that contain examples
 set(example_dirs
     audio

examples/textures/textures_portal_window.c

@@ -0,0 +1,224 @@
+/*******************************************************************************************
+*
+*   raylib [textures] example - portal window
+*
+*   Example demonstrates rendering a second scene to a texture and projecting it onto a
+*   quad to create the illusion of a portal window looking into another place. The second
+*   scene is rendered with an off-axis ("oblique frustum") projection matched to the
+*   viewer's actual position relative to the window, so the illusion holds up correctly
+*   as the player moves and looks around, rather than only looking right from one spot
+*
+*   Example complexity rating: [★★★☆] 3/4
+*
+*   Example originally created with raylib 6.0, last time updated with raylib 6.0
+*
+*   Example contributed by PanicTitan (@PanicTitan) and reviewed by Ramon Santamaria (@raysan5)
+*
+*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
+*   BSD-like license that allows static linking with closed source software
+*
+*   Copyright (c) 2025 PanicTitan (@PanicTitan)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+#include "raymath.h"
+#include "rlgl.h"
+#include <math.h>
+
+//------------------------------------------------------------------------------------
+// Module Functions Declaration
+//------------------------------------------------------------------------------------
+static void BeginPortalMode3D(Vector3 eye, Vector3 bottomLeft, Vector3 bottomRight, Vector3 topLeft, float nearPlane, float farPlane);
+
+//------------------------------------------------------------------------------------
+// Program main entry point
+//------------------------------------------------------------------------------------
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    const int screenWidth = 800;
+    const int screenHeight = 450;
+
+    InitWindow(screenWidth, screenHeight, "raylib [textures] example - portal window");
+
+    // Camera to navigate the "real world" (Dimension A)
+    Camera3D camera = { 0 };
+    camera.position = (Vector3){ 0.0f, 2.5f, 7.0f };
+    camera.target = (Vector3){ 0.0f, 1.8f, 0.0f };
+    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };
+    camera.fovy = 45.0f;
+    camera.projection = CAMERA_PERSPECTIVE;
+
+    // The archway opening, in Dimension A world space (used both to draw the frame and
+    // as the window rectangle the oblique projection is built from)
+    Vector3 archBottomLeft  = { -1.5f, 0.0f, 0.0f };
+    Vector3 archBottomRight = {  1.5f, 0.0f, 0.0f };
+    Vector3 archTopLeft     = { -1.5f, 4.0f, 0.0f };
+
+    // The archway sits at portalA and looks out onto portalB, far away in world space.
+    // Every frame, Dimension B gets rendered to a texture using the same relative eye
+    // and window position, shifted by the offset between the two portals
+    Vector3 portalA = { 0.0f, 0.0f, 0.0f };
+    Vector3 portalB = { 0.0f, 0.0f, -60.0f };
+    RenderTexture2D portalView = LoadRenderTexture(480, 640);
+
+    DisableCursor();        // Lock cursor for first-person free camera controls
+    SetTargetFPS(60);
+    //--------------------------------------------------------------------------------------
+
+    // Main game loop
+    while (!WindowShouldClose())    // Detect window close button or ESC key
+    {
+        // Update
+        //----------------------------------------------------------------------------------
+        UpdateCamera(&camera, CAMERA_FREE);
+        float time = (float)GetTime();
+
+        // Eye and window corners, shifted into Dimension B so they match the player's
+        // actual position and viewing angle relative to the archway
+        Vector3 offset = Vector3Subtract(portalB, portalA);
+        Vector3 eyeInB = Vector3Add(camera.position, offset);
+        Vector3 blInB = Vector3Add(archBottomLeft, offset);
+        Vector3 brInB = Vector3Add(archBottomRight, offset);
+        Vector3 tlInB = Vector3Add(archTopLeft, offset);
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        // Render Dimension B into an offscreen texture, using an oblique projection so
+        // its perspective lines up with the archway exactly as the real camera sees it
+        BeginTextureMode(portalView);
+
+            ClearBackground((Color){ 10, 5, 20, 255 });
+
+            BeginPortalMode3D(eyeInB, blInB, brInB, tlInB, 0.05f, 100.0f);
+
+                DrawGrid(30, 0.8f);
+
+                // Floating pulsing core sphere
+                Vector3 corePos = Vector3Add(portalB, (Vector3){ 0.0f, 2.0f + sinf(time * 2.5f) * 0.4f, -4.0f });
+                DrawSphere(corePos, 1.2f, PURPLE);
+                DrawSphereWires(corePos, 1.25f, 16, 16, MAGENTA);
+
+                // Orbiting cubes
+                for (int i = 0; i < 4; i++)
+                {
+                    float angle = time * 1.5f + i * (PI / 2.0f);
+                    Vector3 pos = Vector3Add(portalB, (Vector3){
+                        sinf(angle) * 2.5f,
+                        2.0f + cosf(time * 3.0f + i) * 0.5f,
+                        -4.0f + cosf(angle) * 2.5f });
+
+                    DrawCube(pos, 0.5f, 0.5f, 0.5f, LIME);
+                    DrawCubeWires(pos, 0.52f, 0.52f, 0.52f, DARKGREEN);
+                }
+
+            EndMode3D();
+
+        EndTextureMode();
+
+        BeginDrawing();
+
+            ClearBackground((Color){ 15, 18, 26, 255 });
+
+            BeginMode3D(camera);
+
+                DrawGrid(20, 1.0f);
+
+                // Side pillars
+                DrawCube((Vector3){ -3.5f, 2.0f, 0.0f }, 0.8f, 4.0f, 0.8f, DARKGRAY);
+                DrawCubeWires((Vector3){ -3.5f, 2.0f, 0.0f }, 0.8f, 4.0f, 0.8f, ORANGE);
+                DrawCube((Vector3){ 3.5f, 2.0f, 0.0f }, 0.8f, 4.0f, 0.8f, DARKGRAY);
+                DrawCubeWires((Vector3){ 3.5f, 2.0f, 0.0f }, 0.8f, 4.0f, 0.8f, ORANGE);
+
+                // Golden archway frame and solid base
+                DrawCubeWires((Vector3){ 0.0f, 2.0f, 0.0f }, 3.2f, 4.2f, 0.2f, GOLD);
+                DrawCube((Vector3){ 0.0f, 0.05f, 0.0f }, 3.4f, 0.1f, 0.6f, MAROON);
+
+                // Solid backing wall, only ever seen if looking at the archway from behind
+                DrawCube((Vector3){ 0.0f, 2.0f, -0.05f }, 3.1f, 4.1f, 0.05f, DARKBLUE);
+
+                // The portal opening itself: a plain quad textured with the Dimension B
+                // render, filling the archway exactly, so nothing "leaks" outside its shape
+                rlSetTexture(portalView.texture.id);
+                rlBegin(RL_QUADS);
+                    rlColor4ub(255, 255, 255, 255);
+                    rlNormal3f(0.0f, 0.0f, 1.0f);
+                    rlTexCoord2f(0.0f, 0.0f); rlVertex3f(archBottomLeft.x, archBottomLeft.y, archBottomLeft.z);
+                    rlTexCoord2f(1.0f, 0.0f); rlVertex3f(archBottomRight.x, archBottomRight.y, archBottomRight.z);
+                    rlTexCoord2f(1.0f, 1.0f); rlVertex3f(archBottomRight.x, 4.0f, archBottomRight.z);
+                    rlTexCoord2f(0.0f, 1.0f); rlVertex3f(archTopLeft.x, archTopLeft.y, archTopLeft.z);
+                rlEnd();
+                rlSetTexture(0);
+
+            EndMode3D();
+
+            // HUD overlay
+            DrawRectangle(15, 15, 400, 85, Fade(BLACK, 0.75f));
+            DrawRectangleLines(15, 15, 400, 85, GOLD);
+            DrawText("PORTAL WINDOW", 28, 25, 20, GOLD);
+            DrawText("Look through the golden arch into Dimension B", 28, 52, 14, RAYWHITE);
+            DrawText("Controls: Mouse to look | WASD to move", 28, 72, 12, GRAY);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    UnloadRenderTexture(portalView);
+
+    CloseWindow();        // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition
+//----------------------------------------------------------------------------------
+
+// Starts a 3D mode using an off-axis ("oblique frustum") projection, built directly from
+// an eye point and 3 corners of a rectangular window, instead of a fovy centered straight
+// ahead of the camera. This is the standard technique for rendering a scene as seen through
+// a window that isn't necessarily faced head-on (also used for multi-monitor and VR
+// rendering) - the key difference from a normal Camera3D is that the frustum is allowed
+// to be asymmetric, so perspective lines through the window line up correctly from any
+// eye position, instead of behaving like a flat image pasted onto the window
+static void BeginPortalMode3D(Vector3 eye, Vector3 bottomLeft, Vector3 bottomRight, Vector3 topLeft, float nearPlane, float farPlane)
+{
+    Vector3 right = Vector3Normalize(Vector3Subtract(bottomRight, bottomLeft));
+    Vector3 up = Vector3Normalize(Vector3Subtract(topLeft, bottomLeft));
+    Vector3 normal = Vector3Normalize(Vector3CrossProduct(right, up));
+
+    // Vectors from the eye to 3 corners of the window, used to project the window onto
+    // the near plane and read off how far it extends left/right/bottom/top of the eye
+    Vector3 toBL = Vector3Subtract(bottomLeft, eye);
+    Vector3 toBR = Vector3Subtract(bottomRight, eye);
+    Vector3 toTL = Vector3Subtract(topLeft, eye);
+
+    float dist = -Vector3DotProduct(toBL, normal);
+    if (dist < 0.01f) dist = 0.01f;      // Keep the eye from crossing the window plane
+
+    float scale = nearPlane/dist;
+
+    rlDrawRenderBatchActive();
+
+    rlMatrixMode(RL_PROJECTION);
+    rlPushMatrix();
+    rlSetMatrixProjection(MatrixFrustum(
+        Vector3DotProduct(right, toBL)*scale, Vector3DotProduct(right, toBR)*scale,
+        Vector3DotProduct(up, toBL)*scale, Vector3DotProduct(up, toTL)*scale,
+        nearPlane, farPlane));
+
+    // View orientation is fixed to the window's own plane (looking straight through it
+    // along its normal), NOT aimed at any target - that's what the asymmetric frustum
+    // above is for, and is what lets the eye move off to one side without distorting
+    rlMatrixMode(RL_MODELVIEW);
+    rlLoadIdentity();
+    rlMultMatrixf(MatrixToFloat(MatrixLookAt(eye, Vector3Subtract(eye, normal), up)));
+
+    rlEnableDepthTest();
+}

src/CMakeLists.txt

@@ -114,6 +114,20 @@ if (NOT BUILD_SHARED_LIBS)
 
     if (NOT glfw3_FOUND)
         list(REMOVE_ITEM raylib_install_private_libs glfw)
+
+        # Bundled GLFW links its Cocoa backend frameworks privately, so they
+        # must be propagated to consumers of the static library, whose final
+        # link line would otherwise miss them. Only the Desktop platform uses
+        # bundled GLFW; other platforms (e.g. Memory) have no Cocoa/GLFW symbols.
+        if (APPLE AND PLATFORM STREQUAL "Desktop")
+            find_library(COCOA_FRAMEWORK Cocoa)
+            find_library(IOKIT_FRAMEWORK IOKit)
+            find_library(QUARTZCORE_FRAMEWORK QuartzCore)
+            list(APPEND raylib_install_private_libs
+                ${COCOA_FRAMEWORK}
+                ${IOKIT_FRAMEWORK}
+                ${QUARTZCORE_FRAMEWORK})
+        endif ()
     endif()
 
     foreach(lib IN LISTS raylib_install_private_libs)