new models_magicavoxel_loading example (#1940)

* new models_magicavoxel_loading example

* Portable header-only file "magicavoxel_loader.h" for MagicaVoxel loader example.

* models_magicavoxel_loading example added to CMakeLists.txt and Makefile

* fix models_magicavoxel_loading example for linux.

* * vox_loader into "src/external/vox_loader.h"
 * vox file support for "models.c"
 * updated example "models/models_magicavoxel_loading.c"

* * Fix Vox_FreeArrays (removed memory leak)

* * removed magicavoxel_loader.h

* * Revert vs2019 solution

6 files changed, 157 insertions, 1 deletions

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index ad391edd..d102eb4c 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -86,7 +86,9 @@ if (${PLATFORM} MATCHES "Android")
     list(REMOVE_ITEM example_sources ${CMAKE_CURRENT_SOURCE_DIR}/models/models_obj_viewer.c)
     list(REMOVE_ITEM example_sources ${CMAKE_CURRENT_SOURCE_DIR}/models/models_animation.c)
     list(REMOVE_ITEM example_sources ${CMAKE_CURRENT_SOURCE_DIR}/models/models_first_person_maze.c)
+	list(REMOVE_ITEM example_sources ${CMAKE_CURRENT_SOURCE_DIR}/models/models_magicavoxel_loading.c)
     
+	
     list(REMOVE_ITEM example_sources ${CMAKE_CURRENT_SOURCE_DIR}/shaders/shaders_custom_uniform.c)
     list(REMOVE_ITEM example_sources ${CMAKE_CURRENT_SOURCE_DIR}/shaders/shaders_model_shader.c)
     list(REMOVE_ITEM example_sources ${CMAKE_CURRENT_SOURCE_DIR}/shaders/shaders_postprocessing.c)
diff --git a/examples/Makefile b/examples/Makefile
index 5abf0c70..f5cb2175 100644
--- a/examples/Makefile
+++ b/examples/Makefile
@@ -466,7 +466,8 @@ MODELS = \
     models/models_skybox \
     models/models_yaw_pitch_roll \
     models/models_heightmap \
-    models/models_waving_cubes
+    models/models_waving_cubes \
+	models/models_magicavoxel_loading
 
 SHADERS = \
     shaders/shaders_model_shader \
diff --git a/examples/models/models_magicavoxel_loading.c b/examples/models/models_magicavoxel_loading.c
new file mode 100644
index 00000000..bb1389d6
--- /dev/null
+++ b/examples/models/models_magicavoxel_loading.c
@@ -0,0 +1,153 @@
+/*******************************************************************************************
+*
+*   raylib [models] example - magicavoxel loader and viewer
+*
+*   This example has been created using raylib 3.8 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Example contributed by Johann Nadalutti 
+*
+*   Copyright (c) 2021 Johann Nadalutti 
+*
+********************************************************************************************/
+
+#include "raylib.h"
+#include "raymath.h"
+
+#include <string.h>
+
+
+// VOX Files to load and view
+
+#define NUM_VOX_FILES  3
+
+const char* szVoxFiles[] = {
+	"resources/vox/chr_knight.vox",
+	"resources/vox/chr_sword.vox",
+	"resources/vox/monu9.vox"
+};
+
+
+int main(void)
+{
+	// Initialization
+	//--------------------------------------------------------------------------------------
+	const int screenWidth = 800;
+	const int screenHeight = 450;
+
+	InitWindow(screenWidth, screenHeight, "raylib [models] example - magicavoxel loading");
+
+	// Load MagicaVoxel files
+	Model models[NUM_VOX_FILES] = { 0 };
+
+	for (int i = 0; i < NUM_VOX_FILES; i++)
+	{
+		// Load MagicaVoxel File and build model
+		double t0, t1;
+		t0 = GetTime() * 1000.0;
+
+		models[i] = LoadModel(szVoxFiles[i]);
+
+		t1 = GetTime() * 1000.0;
+		TraceLog(LOG_INFO, TextFormat("Vox <%s> loaded in %f ms", GetFileName(szVoxFiles[i]), t1 - t0));
+
+		//Compute model matrix
+		BoundingBox  bb = GetModelBoundingBox(models[i]);
+		Vector3 center;
+		center.x = -(((bb.max.x - bb.min.x) / 2));
+		center.y = -(((bb.max.y - bb.min.y) / 2));
+		center.z = -(((bb.max.z - bb.min.z) / 2));
+
+		Matrix matP = MatrixTranslate(center.x, center.z, 0);
+		Matrix matR = MatrixRotateX(90 * DEG2RAD);
+		models[i].transform = MatrixMultiply(matP, matR);
+
+
+	}
+
+
+	// Define the camera to look into our 3d world
+	Camera camera = { { 0.0f, 10.0f, 10.0f }, { 0.0f, 0.0f, 0.0f }, { 0.0f, 1.0f, 0.0f }, 45.0f, 0 };
+
+	// Model drawing position
+	Vector3 position = { 0.0f, 0.0f, 0.0f };
+
+	int currentModel = 0;
+
+
+
+	SetCameraMode(camera, CAMERA_ORBITAL);  // Set a orbital camera mode
+
+	SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
+
+	//--------------------------------------------------------------------------------------
+	// Main game loop
+	//--------------------------------------------------------------------------------------
+	while (!WindowShouldClose())    // Detect window close button or ESC key
+	{
+		//--------------------------------------------------------------------------------------
+		// Update
+		//----------------------------------------------------------------------------------
+		UpdateCamera(&camera);      // Update internal camera and our camera
+
+		if (IsMouseButtonPressed(MOUSE_BUTTON_LEFT))
+		{
+			currentModel = (currentModel + 1) % NUM_VOX_FILES; // Cycle between models
+		}
+
+		if (IsKeyPressed(KEY_RIGHT))
+		{
+			currentModel++;
+			if (currentModel >= NUM_VOX_FILES) currentModel = 0;
+		}
+		else if (IsKeyPressed(KEY_LEFT))
+		{
+			currentModel--;
+			if (currentModel < 0) currentModel = NUM_VOX_FILES - 1;
+		}
+
+		//----------------------------------------------------------------------------------
+		// Draw
+		//----------------------------------------------------------------------------------
+		BeginDrawing();
+
+		ClearBackground(RAYWHITE);
+
+		//Display model
+		BeginMode3D(camera);
+
+		Vector3 rotAxis = { 1,0,0 };
+		Vector3 scale = { 1,1,1 };
+
+
+		DrawModelEx(models[currentModel], position, rotAxis, 0, scale, WHITE);
+		//DrawModelWiresEx(models[currentModel], position, rotAxis, -90.0f, scale, BLACK);
+
+		DrawGrid(10, 1.0);
+
+		EndMode3D();
+
+		//Display debug infos
+		DrawRectangle(30, 400, 310, 30, Fade(SKYBLUE, 0.5f));
+		DrawRectangleLines(30, 400, 310, 30, Fade(DARKBLUE, 0.5f));
+		DrawText("MOUSE LEFT BUTTON to CYCLE VOX MODELS", 40, 410, 10, BLUE);
+
+		DrawText(GetFileName(szVoxFiles[currentModel]), 100, 10, 20, DARKBLUE);
+
+		EndDrawing();
+		//----------------------------------------------------------------------------------
+	}
+
+	// De-Initialization
+	//--------------------------------------------------------------------------------------
+
+	// Unload models data (GPU VRAM)
+	for (int i = 0; i < NUM_VOX_FILES; i++) UnloadModel(models[i]);
+
+	CloseWindow();          // Close window and OpenGL context
+	//--------------------------------------------------------------------------------------
+
+	return 0;
+}
+
+
diff --git a/examples/models/resources/vox/chr_knight.vox b/examples/models/resources/vox/chr_knight.vox
new file mode 100644
index 00000000..c921bf5c
--- /dev/null
+++ b/examples/models/resources/vox/chr_knight.vox
diff --git a/examples/models/resources/vox/chr_sword.vox b/examples/models/resources/vox/chr_sword.vox
new file mode 100644
index 00000000..05fc4826
--- /dev/null
+++ b/examples/models/resources/vox/chr_sword.vox
diff --git a/examples/models/resources/vox/monu9.vox b/examples/models/resources/vox/monu9.vox
new file mode 100644
index 00000000..fd771112
--- /dev/null
+++ b/examples/models/resources/vox/monu9.vox