git subrepo clone (merge) https://github.com/HarbourMasters/otrgui.git OTRGui

subrepo:
  subdir:   "OTRGui"
  merged:   "a6066a251"
upstream:
  origin:   "https://github.com/HarbourMasters/otrgui.git"
  branch:   "master"
  commit:   "a6066a251"
git-subrepo:
  version:  "0.4.1"
  origin:   "???"
  commit:   "???"

OTRGui/libs/raylib/examples/shaders/shaders_raymarching.c

@@ -0,0 +1,113 @@
+/*******************************************************************************************
+*
+*   raylib [shaders] example - Raymarching shapes generation
+*
+*   NOTE: This example requires raylib OpenGL 3.3 for shaders support and only #version 330
+*         is currently supported. OpenGL ES 2.0 platforms are not supported at the moment.
+*
+*   This example has been created using raylib 2.0 (www.raylib.com)
+*   raylib is licensed under an unmodified zlib/libpng license (View raylib.h for details)
+*
+*   Copyright (c) 2018 Ramon Santamaria (@raysan5)
+*
+********************************************************************************************/
+
+#include "raylib.h"
+
+#if defined(PLATFORM_DESKTOP)
+    #define GLSL_VERSION            330
+#else   // PLATFORM_RPI, PLATFORM_ANDROID, PLATFORM_WEB -> Not supported at this moment
+    #define GLSL_VERSION            100
+#endif
+
+int main(void)
+{
+    // Initialization
+    //--------------------------------------------------------------------------------------
+    int screenWidth = 800;
+    int screenHeight = 450;
+
+    SetConfigFlags(FLAG_WINDOW_RESIZABLE);
+    InitWindow(screenWidth, screenHeight, "raylib [shaders] example - raymarching shapes");
+
+    Camera camera = { 0 };
+    camera.position = (Vector3){ 2.5f, 2.5f, 3.0f };    // Camera position
+    camera.target = (Vector3){ 0.0f, 0.0f, 0.7f };      // Camera looking at point
+    camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };          // Camera up vector (rotation towards target)
+    camera.fovy = 65.0f;                                // Camera field-of-view Y
+
+    SetCameraMode(camera, CAMERA_FREE);                 // Set camera mode
+
+    // Load raymarching shader
+    // NOTE: Defining 0 (NULL) for vertex shader forces usage of internal default vertex shader
+    Shader shader = LoadShader(0, TextFormat("resources/shaders/glsl%i/raymarching.fs", GLSL_VERSION));
+
+    // Get shader locations for required uniforms
+    int viewEyeLoc = GetShaderLocation(shader, "viewEye");
+    int viewCenterLoc = GetShaderLocation(shader, "viewCenter");
+    int runTimeLoc = GetShaderLocation(shader, "runTime");
+    int resolutionLoc = GetShaderLocation(shader, "resolution");
+
+    float resolution[2] = { (float)screenWidth, (float)screenHeight };
+    SetShaderValue(shader, resolutionLoc, resolution, SHADER_UNIFORM_VEC2);
+
+    float runTime = 0.0f;
+
+    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 camera
+
+        float cameraPos[3] = { camera.position.x, camera.position.y, camera.position.z };
+        float cameraTarget[3] = { camera.target.x, camera.target.y, camera.target.z };
+
+        float deltaTime = GetFrameTime();
+        runTime += deltaTime;
+
+        // Set shader required uniform values
+        SetShaderValue(shader, viewEyeLoc, cameraPos, SHADER_UNIFORM_VEC3);
+        SetShaderValue(shader, viewCenterLoc, cameraTarget, SHADER_UNIFORM_VEC3);
+        SetShaderValue(shader, runTimeLoc, &runTime, SHADER_UNIFORM_FLOAT);
+
+        // Check if screen is resized
+        if (IsWindowResized())
+        {
+            screenWidth = GetScreenWidth();
+            screenHeight = GetScreenHeight();
+            float resolution[2] = { (float)screenWidth, (float)screenHeight };
+            SetShaderValue(shader, resolutionLoc, resolution, SHADER_UNIFORM_VEC2);
+        }
+        //----------------------------------------------------------------------------------
+
+        // Draw
+        //----------------------------------------------------------------------------------
+        BeginDrawing();
+
+            ClearBackground(RAYWHITE);
+
+            // We only draw a white full-screen rectangle,
+            // frame is generated in shader using raymarching
+            BeginShaderMode(shader);
+                DrawRectangle(0, 0, screenWidth, screenHeight, WHITE);
+            EndShaderMode();
+
+            DrawText("(c) Raymarching shader by Iñigo Quilez. MIT License.", screenWidth - 280, screenHeight - 20, 10, BLACK);
+
+        EndDrawing();
+        //----------------------------------------------------------------------------------
+    }
+
+    // De-Initialization
+    //--------------------------------------------------------------------------------------
+    UnloadShader(shader);           // Unload shader
+
+    CloseWindow();                  // Close window and OpenGL context
+    //--------------------------------------------------------------------------------------
+
+    return 0;
+}