Added texture caching to the texture loading process

diff --git a/src/texture.cpp b/src/texture.cpp
index 560481201814667971e827e029e010327c286408..d2b2627f364d26892068dd37c3c9d733545956e1 100644 (file)
--- a/src/texture.cpp
+++ b/src/texture.cpp
@@ -1,20 +1,62 @@
+/**
+ * @file texture.cpp
+ * Handles all texture loading 
+ *
+ * Copyright (C) 2019  Belle-Isle, Andrew <drumsetmonkey@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
 #include "texture.hpp"
 
+#include <unordered_map>
+#include <iostream>
+
+// Stores a list of all textures we've already loaded. This makes sure we don't
+// waste our precious CPU cycles reloading a texture.
+std::unordered_map<std::string, GLuint> textureCache;
+
 Texture::Texture(std::string filename)
 {
-    unsigned char* image = SOIL_load_image(filename.c_str(),
-                                           &width, &height, 0,
-                                           SOIL_LOAD_RGBA);
-
-    glGenTextures(1, &tex);                            // Turns "object" into a texture
-       glBindTexture(GL_TEXTURE_2D, tex);      // Binds "object" to the top of the stack
-       glPixelStoref(GL_UNPACK_ALIGNMENT, 1);
-       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);      // Sets the "min" filter
-       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);      // The the "max" filter of the stack
-       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); // Wrap the texture to the matrix
-       glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); //
-       glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0,
-                                GL_RGBA, GL_UNSIGNED_BYTE, image);
-
-    SOIL_free_image_data(image);
+    // Search to see if this texture has already been loading
+    auto cacheSearch = textureCache.find(filename);
+
+    if (cacheSearch == textureCache.end()) {
+    // If this texture hasn't been loading
+
+        unsigned char* image = SOIL_load_image(filename.c_str(),
+                                               &width, &height, 0,
+                                               SOIL_LOAD_RGBA);
+
+        glGenTextures(1, &tex);
+        glBindTexture(GL_TEXTURE_2D, tex);
+        glPixelStoref(GL_UNPACK_ALIGNMENT, 1);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+        glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0,
+                     GL_RGBA, GL_UNSIGNED_BYTE, image);
+
+        SOIL_free_image_data(image);
+
+        // Add new texture to the texture cache
+        textureCache.emplace(filename, tex);
+
+    } else {
+    // If this texture has been loaded, just return the loaded texture
+        tex = cacheSearch->second;
+    }
 }