1 files changed, 46 insertions, 6 deletions

diff --git a/src/RenderBackend/OpenGL/Texture2D.cpp b/src/RenderBackend/OpenGL/Texture2D.cpp
index 07d807a..a561f6e 100644
--- a/src/RenderBackend/OpenGL/Texture2D.cpp
+++ b/src/RenderBackend/OpenGL/Texture2D.cpp
@@ -1,15 +1,54 @@
 #include "../../../include/RenderBackend/OpenGL/Texture2D.hpp"
-#include "../../../include/RenderBackend/OpenGL/Image.hpp"
 #include "../../../include/RenderBackend/OpenGL/opengl.hpp"
+#include "../../../include/Image.hpp"
+#include <stack>
 #include <cassert>
 
-namespace amalgine
-{
+namespace amalgine {
+    struct TextureIdAllocator {
+        TextureIdAllocator(){
+            glGetIntegerv(GL_MAX_TEXTURE_IMAGE_UNITS, &max_texture_units);
+            if(max_texture_units < 1)
+                max_texture_units = 1;
+            printf("max texture units: %d\n", max_texture_units);
+        }
+
+        u32 get_free_texture_id() {
+            if(!free_spots.empty()) {
+                u32 texture_id = free_spots.top();
+                free_spots.pop();
+                return texture_id;
+            }
+
+            if(texture_id_counter + 1 == max_texture_units) {
+                fprintf(stderr, "Error: No free spot left for textures, resetting counter\n");
+                texture_id_counter = 0;
+            }
+
+            return texture_id_counter++;
+        }
+
+        void free_texture_id(i32 texture_id) {
+            free_spots.push(texture_id);
+        }
+        
+        std::stack<u32> free_spots;
+        i32 texture_id_counter = 0;
+        i32 max_texture_units = 0;
+    };
+
+    static TextureIdAllocator *texture_id_allocator = nullptr;
+
     Texture2D::Texture2D(Image *image)
     {
         assert(image);
-        glGenTextures(1, &textureId);
-        glBindTexture(GL_TEXTURE_2D, textureId);
+        if(!texture_id_allocator)
+            texture_id_allocator = new TextureIdAllocator();
+
+        texture_id = texture_id_allocator->get_free_texture_id();
+        glGenTextures(1, &texture_ref);
+        glActiveTexture(GL_TEXTURE0 + texture_id);
+        glBindTexture(GL_TEXTURE_2D, texture_ref);
         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, image->getWidth(), image->getHeight(), 0, GL_RGB, GL_UNSIGNED_BYTE, image->getData());
         
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
@@ -21,6 +60,7 @@ namespace amalgine
 
     Texture2D::~Texture2D()
     {
-        glDeleteTextures(1, &textureId);
+        texture_id_allocator->free_texture_id(texture_id);
+        glDeleteTextures(1, &texture_ref);
     }
 }