Add loading screen with random WOWEE splash images

- Add loading screen system with stb_image for JPEG loading
- Two loading screen images (orc and dwarf) randomly selected
- Display loading screen while terrain data loads
- Cache WMO inverse matrices to reduce per-frame computation
- Stub WMO liquid rendering (needs coordinate system fix)
- Update spawn point to Stormwind Trade District

src/core/application.cpp

@@ -16,6 +16,7 @@
 #include "rendering/character_renderer.hpp"
 #include "rendering/wmo_renderer.hpp"
 #include "rendering/minimap.hpp"
+#include "rendering/loading_screen.hpp"
 #include <imgui.h>
 #include "pipeline/m2_loader.hpp"
 #include "pipeline/wmo_loader.hpp"
@@ -107,11 +108,42 @@ bool Application::initialize() {
 void Application::run() {
     LOG_INFO("Starting main loop");
 
-    // Auto-load terrain for testing
-    if (assetManager && assetManager->isInitialized() && renderer) {
-        renderer->loadTestTerrain(assetManager.get(), "World\\Maps\\Azeroth\\Azeroth_32_49.adt");
-        // Spawn player character with third-person camera
-        spawnPlayerCharacter();
+    // Show loading screen while loading initial data
+    rendering::LoadingScreen loadingScreen;
+    if (loadingScreen.initialize()) {
+        // Render loading screen
+        loadingScreen.setStatus("Initializing...");
+        loadingScreen.render();
+        window->swapBuffers();
+
+        // Load terrain data
+        if (assetManager && assetManager->isInitialized() && renderer) {
+            loadingScreen.setStatus("Loading terrain...");
+            loadingScreen.render();
+            window->swapBuffers();
+
+            renderer->loadTestTerrain(assetManager.get(), "World\\Maps\\Azeroth\\Azeroth_32_49.adt");
+
+            loadingScreen.setStatus("Spawning character...");
+            loadingScreen.render();
+            window->swapBuffers();
+
+            // Spawn player character with third-person camera
+            spawnPlayerCharacter();
+        }
+
+        loadingScreen.setStatus("Ready!");
+        loadingScreen.render();
+        window->swapBuffers();
+        SDL_Delay(500);  // Brief pause to show "Ready!"
+
+        loadingScreen.shutdown();
+    } else {
+        // Fallback: load without loading screen
+        if (assetManager && assetManager->isInitialized() && renderer) {
+            renderer->loadTestTerrain(assetManager.get(), "World\\Maps\\Azeroth\\Azeroth_32_49.adt");
+            spawnPlayerCharacter();
+        }
     }
 
     auto lastTime = std::chrono::high_resolution_clock::now();
@@ -452,146 +484,7 @@ void Application::run() {
                         LOG_INFO("Minimap ", renderer->getMinimap()->isEnabled() ? "enabled" : "disabled");
                     }
                 }
-                // O: Spawn test WMO building at camera position
-                // Shift+O: Load real WMO from MPQ
-                else if (event.key.keysym.scancode == SDL_SCANCODE_O) {
-                    // Check if Shift is held for real WMO loading
-                    bool shiftHeld = (event.key.keysym.mod & KMOD_SHIFT) != 0;
-
-                    if (shiftHeld && assetManager && assetManager->isInitialized() &&
-                        renderer && renderer->getWMORenderer() && renderer->getCamera()) {
-                        // Load a real WMO from MPQ (try a simple mailbox)
-                        auto* wmoRenderer = renderer->getWMORenderer();
-                        auto* camera = renderer->getCamera();
-
-                        // Try to load a simple WMO - mailbox is small and common
-                        const char* wmoPath = "World\\wmo\\Azeroth\\Buildings\\Human_Mailbox\\Human_Mailbox.wmo";
-                        LOG_INFO("Loading real WMO from MPQ: ", wmoPath);
-
-                        auto wmoData = assetManager->readFile(wmoPath);
-                        if (wmoData.empty()) {
-                            LOG_WARNING("Failed to load WMO file from MPQ. Trying alternative path...");
-                            // Try alternative path
-                            wmoPath = "World\\wmo\\Dungeon\\LD_Prison\\LD_Prison_Cell01.wmo";
-                            wmoData = assetManager->readFile(wmoPath);
-                        }
-
-                        if (!wmoData.empty()) {
-                            // Parse WMO
-                            pipeline::WMOModel wmoModel = pipeline::WMOLoader::load(wmoData);
-
-                            if (wmoModel.isValid()) {
-                                // Use unique model ID (2 for real WMOs)
-                                static uint32_t nextModelId = 2;
-                                uint32_t modelId = nextModelId++;
-
-                                if (wmoRenderer->loadModel(wmoModel, modelId)) {
-                                    // Spawn WMO in front of camera
-                                    glm::vec3 spawnPos = camera->getPosition() + camera->getForward() * 20.0f;
-                                    uint32_t instanceId = wmoRenderer->createInstance(modelId, spawnPos);
-
-                                    if (instanceId > 0) {
-                                        LOG_INFO("Spawned real WMO (", wmoModel.groups.size(), " groups) at (",
-                                                static_cast<int>(spawnPos.x), ", ",
-                                                static_cast<int>(spawnPos.y), ", ",
-                                                static_cast<int>(spawnPos.z), ")");
-                                        LOG_INFO("WMO has ", wmoModel.materials.size(), " materials, ",
-                                                wmoModel.textures.size(), " textures");
-                                    }
-                                } else {
-                                    LOG_ERROR("Failed to load WMO model into renderer");
-                                }
-                            } else {
-                                LOG_ERROR("Failed to parse WMO file");
-                            }
-                        } else {
-                            LOG_WARNING("WMO file not found in MPQ archives");
-                            LOG_INFO("Make sure WOW_DATA_PATH environment variable points to valid WoW 3.3.5a installation");
-                        }
-                    }
-                    else if (renderer && renderer->getWMORenderer() && renderer->getCamera()) {
-                        auto* wmoRenderer = renderer->getWMORenderer();
-                        auto* camera = renderer->getCamera();
-
-                        // Create a simple cube building as placeholder WMO
-                        // (Real WMO would be loaded from MPQ)
-                        pipeline::WMOModel testWMO;
-                        testWMO.version = 17;
-                        testWMO.nGroups = 1;
-
-                        // Create a single group with cube geometry
-                        pipeline::WMOGroup group;
-                        group.flags = 0;
-                        group.groupId = 0;
-
-                        // Cube building vertices (larger than character cube)
-                        float size = 5.0f;
-                        std::vector<glm::vec3> cubePos = {
-                            {-size, -size, -size}, { size, -size, -size},
-                            { size,  size, -size}, {-size,  size, -size},
-                            {-size, -size,  size}, { size, -size,  size},
-                            { size,  size,  size}, {-size,  size,  size}
-                        };
-
-                        for (const auto& pos : cubePos) {
-                            pipeline::WMOVertex v;
-                            v.position = pos;
-                            v.normal = glm::normalize(pos);
-                            v.texCoord = glm::vec2(0.5f);
-                            v.color = glm::vec4(0.8f, 0.7f, 0.6f, 1.0f);  // Stone color
-                            group.vertices.push_back(v);
-                        }
-
-                        // Cube indices (12 triangles, 36 indices)
-                        uint16_t cubeIndices[] = {
-                            0,1,2, 0,2,3,  // Front
-                            4,6,5, 4,7,6,  // Back
-                            0,4,5, 0,5,1,  // Bottom
-                            2,6,7, 2,7,3,  // Top
-                            0,3,7, 0,7,4,  // Left
-                            1,5,6, 1,6,2   // Right
-                        };
-                        for (uint16_t idx : cubeIndices) {
-                            group.indices.push_back(idx);
-                        }
-
-                        // Bounding box
-                        group.boundingBoxMin = glm::vec3(-size);
-                        group.boundingBoxMax = glm::vec3(size);
-
-                        // Single batch (no materials for now)
-                        pipeline::WMOBatch batch;
-                        batch.startIndex = 0;
-                        batch.indexCount = 36;
-                        batch.startVertex = 0;
-                        batch.lastVertex = 7;
-                        batch.materialId = 0;
-                        group.batches.push_back(batch);
-
-                        testWMO.groups.push_back(group);
-                        testWMO.boundingBoxMin = glm::vec3(-size);
-                        testWMO.boundingBoxMax = glm::vec3(size);
-
-                        // Load WMO model (reuse ID 1 for simplicity)
-                        static bool wmoModelLoaded = false;
-                        if (!wmoModelLoaded) {
-                            wmoRenderer->loadModel(testWMO, 1);
-                            wmoModelLoaded = true;
-                        }
-
-                        // Spawn WMO in front of camera
-                        glm::vec3 spawnPos = camera->getPosition() + camera->getForward() * 20.0f;
-                        uint32_t instanceId = wmoRenderer->createInstance(1, spawnPos);
-
-                        if (instanceId > 0) {
-                            LOG_INFO("Spawned test WMO building at (",
-                                    static_cast<int>(spawnPos.x), ", ",
-                                    static_cast<int>(spawnPos.y), ", ",
-                                    static_cast<int>(spawnPos.z), ")");
-                        }
-                    }
-                }
-                // P: Remove all WMO buildings
+                // P: Remove all WMO buildings (O key removed)
                 else if (event.key.keysym.scancode == SDL_SCANCODE_P) {
                     if (renderer && renderer->getWMORenderer()) {
                         renderer->getWMORenderer()->clearInstances();

src/rendering/loading_screen.cpp

@@ -0,0 +1,225 @@
+#include "rendering/loading_screen.hpp"
+#include "core/logger.hpp"
+#include <random>
+#include <chrono>
+
+#define STB_IMAGE_IMPLEMENTATION
+#include "stb_image.h"
+
+namespace wowee {
+namespace rendering {
+
+LoadingScreen::LoadingScreen() {
+    // Add loading screen image paths
+    imagePaths.push_back("assets/loading1.jpg");
+    imagePaths.push_back("assets/loading2.jpg");
+}
+
+LoadingScreen::~LoadingScreen() {
+    shutdown();
+}
+
+bool LoadingScreen::initialize() {
+    LOG_INFO("Initializing loading screen");
+
+    // Create simple shader for textured quad
+    const char* vertexSrc = R"(
+        #version 330 core
+        layout (location = 0) in vec2 aPos;
+        layout (location = 1) in vec2 aTexCoord;
+        out vec2 TexCoord;
+        void main() {
+            gl_Position = vec4(aPos, 0.0, 1.0);
+            TexCoord = aTexCoord;
+        }
+    )";
+
+    const char* fragmentSrc = R"(
+        #version 330 core
+        in vec2 TexCoord;
+        out vec4 FragColor;
+        uniform sampler2D screenTexture;
+        void main() {
+            FragColor = texture(screenTexture, TexCoord);
+        }
+    )";
+
+    // Compile vertex shader
+    GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
+    glShaderSource(vertexShader, 1, &vertexSrc, nullptr);
+    glCompileShader(vertexShader);
+
+    GLint success;
+    glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
+    if (!success) {
+        char infoLog[512];
+        glGetShaderInfoLog(vertexShader, 512, nullptr, infoLog);
+        LOG_ERROR("Loading screen vertex shader compilation failed: ", infoLog);
+        return false;
+    }
+
+    // Compile fragment shader
+    GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
+    glShaderSource(fragmentShader, 1, &fragmentSrc, nullptr);
+    glCompileShader(fragmentShader);
+
+    glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
+    if (!success) {
+        char infoLog[512];
+        glGetShaderInfoLog(fragmentShader, 512, nullptr, infoLog);
+        LOG_ERROR("Loading screen fragment shader compilation failed: ", infoLog);
+        return false;
+    }
+
+    // Link shader program
+    shaderId = glCreateProgram();
+    glAttachShader(shaderId, vertexShader);
+    glAttachShader(shaderId, fragmentShader);
+    glLinkProgram(shaderId);
+
+    glGetProgramiv(shaderId, GL_LINK_STATUS, &success);
+    if (!success) {
+        char infoLog[512];
+        glGetProgramInfoLog(shaderId, 512, nullptr, infoLog);
+        LOG_ERROR("Loading screen shader linking failed: ", infoLog);
+        return false;
+    }
+
+    glDeleteShader(vertexShader);
+    glDeleteShader(fragmentShader);
+
+    createQuad();
+    selectRandomImage();
+
+    LOG_INFO("Loading screen initialized");
+    return true;
+}
+
+void LoadingScreen::shutdown() {
+    if (textureId) {
+        glDeleteTextures(1, &textureId);
+        textureId = 0;
+    }
+    if (vao) {
+        glDeleteVertexArrays(1, &vao);
+        vao = 0;
+    }
+    if (vbo) {
+        glDeleteBuffers(1, &vbo);
+        vbo = 0;
+    }
+    if (shaderId) {
+        glDeleteProgram(shaderId);
+        shaderId = 0;
+    }
+}
+
+void LoadingScreen::selectRandomImage() {
+    if (imagePaths.empty()) return;
+
+    // Seed with current time
+    unsigned seed = static_cast<unsigned>(
+        std::chrono::system_clock::now().time_since_epoch().count());
+    std::default_random_engine generator(seed);
+    std::uniform_int_distribution<int> distribution(0, imagePaths.size() - 1);
+
+    currentImageIndex = distribution(generator);
+    LOG_INFO("Selected loading screen: ", imagePaths[currentImageIndex]);
+
+    loadImage(imagePaths[currentImageIndex]);
+}
+
+bool LoadingScreen::loadImage(const std::string& path) {
+    // Delete old texture if exists
+    if (textureId) {
+        glDeleteTextures(1, &textureId);
+        textureId = 0;
+    }
+
+    // Load image with stb_image
+    int channels;
+    stbi_set_flip_vertically_on_load(true);
+    unsigned char* data = stbi_load(path.c_str(), &imageWidth, &imageHeight, &channels, 4);
+
+    if (!data) {
+        LOG_ERROR("Failed to load loading screen image: ", path);
+        return false;
+    }
+
+    LOG_INFO("Loaded loading screen image: ", imageWidth, "x", imageHeight);
+
+    // Create OpenGL texture
+    glGenTextures(1, &textureId);
+    glBindTexture(GL_TEXTURE_2D, textureId);
+
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageWidth, imageHeight, 0,
+                 GL_RGBA, GL_UNSIGNED_BYTE, data);
+
+    stbi_image_free(data);
+    glBindTexture(GL_TEXTURE_2D, 0);
+
+    return true;
+}
+
+void LoadingScreen::createQuad() {
+    // Full-screen quad vertices (position + texcoord)
+    float vertices[] = {
+        // Position    // TexCoord
+        -1.0f,  1.0f,  0.0f, 1.0f,  // Top-left
+        -1.0f, -1.0f,  0.0f, 0.0f,  // Bottom-left
+         1.0f, -1.0f,  1.0f, 0.0f,  // Bottom-right
+
+        -1.0f,  1.0f,  0.0f, 1.0f,  // Top-left
+         1.0f, -1.0f,  1.0f, 0.0f,  // Bottom-right
+         1.0f,  1.0f,  1.0f, 1.0f   // Top-right
+    };
+
+    glGenVertexArrays(1, &vao);
+    glGenBuffers(1, &vbo);
+
+    glBindVertexArray(vao);
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+
+    // Position attribute
+    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)0);
+    glEnableVertexAttribArray(0);
+
+    // Texture coordinate attribute
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)(2 * sizeof(float)));
+    glEnableVertexAttribArray(1);
+
+    glBindVertexArray(0);
+}
+
+void LoadingScreen::render() {
+    if (!textureId || !vao || !shaderId) return;
+
+    // Clear screen
+    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    // Disable depth test for 2D rendering
+    glDisable(GL_DEPTH_TEST);
+
+    // Use shader and bind texture
+    glUseProgram(shaderId);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, textureId);
+
+    // Draw quad
+    glBindVertexArray(vao);
+    glDrawArrays(GL_TRIANGLES, 0, 6);
+    glBindVertexArray(0);
+
+    // Re-enable depth test
+    glEnable(GL_DEPTH_TEST);
+}
+
+} // namespace rendering
+} // namespace wowee

src/rendering/terrain_manager.cpp

@@ -469,15 +469,37 @@ void TerrainManager::finalizeTile(std::unique_ptr<PendingTile> pending) {
         }
 
         int loadedWMOs = 0;
+        int loadedLiquids = 0;
         for (auto& wmoReady : pending->wmoModels) {
             if (wmoRenderer->loadModel(wmoReady.model, wmoReady.modelId)) {
                 uint32_t wmoInstId = wmoRenderer->createInstance(wmoReady.modelId, wmoReady.position, wmoReady.rotation);
                 if (wmoInstId) {
                     wmoInstanceIds.push_back(wmoInstId);
                     loadedWMOs++;
+
+                    // Load WMO liquids (canals, pools, etc.)
+                    if (waterRenderer) {
+                        // Compute the same model matrix as WMORenderer uses
+                        glm::mat4 modelMatrix = glm::mat4(1.0f);
+                        modelMatrix = glm::translate(modelMatrix, wmoReady.position);
+                        modelMatrix = glm::rotate(modelMatrix, wmoReady.rotation.z, glm::vec3(0.0f, 0.0f, 1.0f));
+                        modelMatrix = glm::rotate(modelMatrix, wmoReady.rotation.y, glm::vec3(0.0f, 1.0f, 0.0f));
+                        modelMatrix = glm::rotate(modelMatrix, wmoReady.rotation.x, glm::vec3(1.0f, 0.0f, 0.0f));
+
+                        // Load liquids from each WMO group
+                        for (const auto& group : wmoReady.model.groups) {
+                            if (group.liquid.hasLiquid()) {
+                                waterRenderer->loadFromWMO(group.liquid, modelMatrix, wmoInstId);
+                                loadedLiquids++;
+                            }
+                        }
+                    }
                 }
             }
         }
+        if (loadedLiquids > 0) {
+            LOG_INFO("  Loaded WMO liquids for tile [", x, ",", y, "]: ", loadedLiquids);
+        }
 
         // Upload WMO doodad M2 models
         if (m2Renderer) {
@@ -608,9 +630,13 @@ void TerrainManager::unloadTile(int x, int y) {
         LOG_DEBUG("  Removed ", tile->m2InstanceIds.size(), " M2 instances");
     }
 
-    // Remove WMO instances
+    // Remove WMO instances and their liquids
     if (wmoRenderer) {
         for (uint32_t id : tile->wmoInstanceIds) {
+            // Remove WMO liquids associated with this instance
+            if (waterRenderer) {
+                waterRenderer->removeWMO(id);
+            }
             wmoRenderer->removeInstance(id);
         }
         LOG_DEBUG("  Removed ", tile->wmoInstanceIds.size(), " WMO instances");

src/rendering/water_renderer.cpp

@@ -2,6 +2,7 @@
 #include "rendering/shader.hpp"
 #include "rendering/camera.hpp"
 #include "pipeline/adt_loader.hpp"
+#include "pipeline/wmo_loader.hpp"
 #include "core/logger.hpp"
 #include <GL/glew.h>
 #include <glm/gtc/matrix_transform.hpp>
@@ -209,6 +210,16 @@ void WaterRenderer::removeTile(int tileX, int tileY) {
     }
 }
 
+void WaterRenderer::loadFromWMO([[maybe_unused]] const pipeline::WMOLiquid& liquid,
+                                 [[maybe_unused]] const glm::mat4& modelMatrix,
+                                 [[maybe_unused]] uint32_t wmoId) {
+    // WMO liquid rendering not yet implemented
+}
+
+void WaterRenderer::removeWMO([[maybe_unused]] uint32_t wmoId) {
+    // WMO liquid rendering not yet implemented
+}
+
 void WaterRenderer::clear() {
     for (auto& surface : surfaces) {
         destroyWaterMesh(surface);

src/rendering/wmo_renderer.cpp

@@ -620,6 +620,9 @@ void WMORenderer::WMOInstance::updateModelMatrix() {
     modelMatrix = glm::rotate(modelMatrix, rotation.x, glm::vec3(1.0f, 0.0f, 0.0f));
 
     modelMatrix = glm::scale(modelMatrix, glm::vec3(scale));
+
+    // Cache inverse for collision detection
+    invModelMatrix = glm::inverse(modelMatrix);
 }
 
 GLuint WMORenderer::loadTexture(const std::string& path) {
@@ -728,10 +731,9 @@ std::optional<float> WMORenderer::getFloorHeight(float glX, float glY, float glZ
 
         const ModelData& model = it->second;
 
-        // Transform ray into model-local space
-        glm::mat4 invModel = glm::inverse(instance.modelMatrix);
-        glm::vec3 localOrigin = glm::vec3(invModel * glm::vec4(worldOrigin, 1.0f));
-        glm::vec3 localDir = glm::normalize(glm::vec3(invModel * glm::vec4(worldDir, 0.0f)));
+        // Use cached inverse matrix
+        glm::vec3 localOrigin = glm::vec3(instance.invModelMatrix * glm::vec4(worldOrigin, 1.0f));
+        glm::vec3 localDir = glm::normalize(glm::vec3(instance.invModelMatrix * glm::vec4(worldDir, 0.0f)));
 
         for (const auto& group : model.groups) {
             // Quick bounding box check: does the ray intersect this group's AABB?
@@ -785,10 +787,9 @@ bool WMORenderer::checkWallCollision(const glm::vec3& from, const glm::vec3& to,
         if (it == loadedModels.end()) continue;
 
         const ModelData& model = it->second;
-        glm::mat4 invModel = glm::inverse(instance.modelMatrix);
 
-        // Transform positions into local space
-        glm::vec3 localTo = glm::vec3(invModel * glm::vec4(to, 1.0f));
+        // Transform positions into local space using cached inverse
+        glm::vec3 localTo = glm::vec3(instance.invModelMatrix * glm::vec4(to, 1.0f));
 
         for (const auto& group : model.groups) {
             // Quick bounding box check
@@ -865,8 +866,7 @@ bool WMORenderer::isInsideWMO(float glX, float glY, float glZ, uint32_t* outMode
         if (it == loadedModels.end()) continue;
 
         const ModelData& model = it->second;
-        glm::mat4 invModel = glm::inverse(instance.modelMatrix);
-        glm::vec3 localPos = glm::vec3(invModel * glm::vec4(glX, glY, glZ, 1.0f));
+        glm::vec3 localPos = glm::vec3(instance.invModelMatrix * glm::vec4(glX, glY, glZ, 1.0f));
 
         // Check if inside any group's bounding box
         for (const auto& group : model.groups) {
@@ -890,10 +890,9 @@ float WMORenderer::raycastBoundingBoxes(const glm::vec3& origin, const glm::vec3
 
         const ModelData& model = it->second;
 
-        // Transform ray into local space
-        glm::mat4 invModel = glm::inverse(instance.modelMatrix);
-        glm::vec3 localOrigin = glm::vec3(invModel * glm::vec4(origin, 1.0f));
-        glm::vec3 localDir = glm::normalize(glm::vec3(invModel * glm::vec4(direction, 0.0f)));
+        // Use cached inverse matrix
+        glm::vec3 localOrigin = glm::vec3(instance.invModelMatrix * glm::vec4(origin, 1.0f));
+        glm::vec3 localDir = glm::normalize(glm::vec3(instance.invModelMatrix * glm::vec4(direction, 0.0f)));
 
         for (const auto& group : model.groups) {
             // Ray-AABB intersection (slab method)