added image widget with atlas support and global texture manager

engine/texture.cpp

@@ -1,6 +1,24 @@
 #include "pch.h"
 #include "texture.h"
 #include "image.h"
+#include "util.h"
+
+std::map<uint16_t, Texture2D> TextureManager::m_textures;
+
+bool TextureManager::load(const char* path)
+{
+    uint16_t id = const_hash(path);
+    if (m_textures.count(id) == 0 || !m_textures[id].ready())
+    {
+        return m_textures[id].load(path);
+    }
+    return true;
+}
+
+Texture2D& TextureManager::get(uint16_t id)
+{
+    return m_textures[id];
+}
 
 bool Texture2D::create(int width, int height, GLint format, const uint8_t* data)
 {
@@ -31,6 +49,11 @@ void Texture2D::update(const uint8_t* data)
     glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, m_width, m_height, m_format, GL_UNSIGNED_BYTE, data);
 }
 
+glm::vec2 Texture2D::size() const
+{
+    return { m_width, m_height };
+}
+
 bool Sampler::create(GLint filter /*= GL_LINEAR*/, GLint wrap /*= GL_CLAMP_TO_EDGE*/)
 {
     glGenSamplers(1, &id);
@@ -55,3 +78,4 @@ void Sampler::unbind()
 {
     glBindSampler(current_unit, 0);
 }
+