rename engine to src

src/image.cpp

@@ -0,0 +1,80 @@
+#include "pch.h"
+#include "log.h"
+#include "image.h"
+#include "asset.h"
+
+#include <stb/stb_image.h>
+
+using namespace ui;
+
+bool Image::load(std::string filename)
+{
+    stbi_set_flip_vertically_on_load(false);
+    Asset file;
+    if (!(file.open(filename.c_str()) && file.read_all()))
+    {
+        file.close();
+        return false;
+    }
+    uint8_t* buffer = stbi_load_from_memory(file.m_data, file.m_len, &width, &height, nullptr, 4);
+    file.close();
+    comp = 4;
+    m_data = std::unique_ptr<uint8_t[]>(buffer);
+    return true;
+}
+
+bool Image::load_file(std::string filename)
+{
+    stbi_set_flip_vertically_on_load(false);
+    uint8_t* buffer = stbi_load(filename.c_str(), &width, &height, nullptr, 4);
+    comp = 4;
+    m_data = std::unique_ptr<uint8_t[]>(buffer);
+    return true;
+}
+
+void Image::flip()
+{
+    auto flipped = std::make_unique<uint8_t[]>(width*height*4);
+    int line_size = width * 4;
+    const uint8_t* src = m_data.get();
+    uint8_t* dst = flipped.get() + line_size * (height - 1);
+    for (int y = 0; y < height; y++)
+    {
+        std::copy(src, src+line_size, dst);
+        src += line_size;
+        dst -= line_size;
+    }
+    std::swap(m_data, flipped);
+}
+
+ui::Image ui::Image::resize(int w, int h)
+{
+    Image ret;
+    ret.create(w, h);
+    auto temp = (glm::u8vec4*)ret.data();
+    auto pixels = (glm::u8vec4*)data();
+    float x_ratio = ((float)(width - 1)) / w;
+    float y_ratio = ((float)(height - 1)) / h;
+    int offset = 0;
+    for (int i = 0; i < h; i++) {
+        for (int j = 0; j < w; j++) {
+            int x = (int)(x_ratio * j);
+            int y = (int)(y_ratio * i);
+            float x_diff = (x_ratio * j) - x;
+            float y_diff = (y_ratio * i) - y;
+            int index = y * width + x;
+
+            // range is 0 to 255 thus bitwise AND with 0xff
+            glm::vec4 A = pixels[index];
+            glm::vec4 B = pixels[index + 1];
+            glm::vec4 C = pixels[index + width];
+            glm::vec4 D = pixels[index + width + 1];
+
+            // Y = A(1-w)(1-h) + B(w)(1-h) + C(h)(1-w) + Dwh
+            glm::vec4 gray = A*(1 - x_diff)*(1 - y_diff) + B * (x_diff)*(1 - y_diff) +
+                C * (y_diff)*(1 - x_diff) + D * (x_diff*y_diff);
+            temp[offset++] = glm::clamp(gray, glm::vec4(0), glm::vec4(255));
+        }
+    }
+    return ret;
+}