[PICA] Start working on textures

src/core/renderer_gl/textures.cpp

@@ -0,0 +1,52 @@
+#include "renderer_gl/textures.hpp"
+
+void Texture::allocate() {
+    Helpers::panic("Tried to allocate texture");
+}
+
+void Texture::free() {
+    valid = false;
+
+    if (texture.exists())
+        Helpers::panic("Make this texture free itself");
+}
+
+u64 Texture::sizeInBytes() {
+    u64 pixelCount = u64(size.x()) * u64(size.y());
+
+    switch (format) {
+    case Formats::RGBA8: // 4 bytes per pixel
+        return pixelCount * 4;
+
+    case Formats::RGB8: // 3 bytes per pixel
+        return pixelCount * 3;
+
+    case Formats::RGBA5551: // 2 bytes per pixel
+    case Formats::RGB565:
+    case Formats::RGBA4:
+    case Formats::RG8:
+    case Formats::IA8:
+        return pixelCount * 2;
+
+    case Formats::A8: // 1 byte per pixel
+    case Formats::I8:
+    case Formats::IA4:
+        return pixelCount;
+
+    case Formats::I4: // 4 bits per pixel
+    case Formats::A4:
+        return pixelCount / 2;
+
+    case Formats::ETC1: // Compressed formats
+    case Formats::ETC1A4: {
+        // Number of 8x8 tiles
+        const u64 tileCount = pixelCount / 64;
+        // Each 8x8 consists of 4 4x4 tiles, which are 8 bytes each on ETC1 and 16 bytes each on ETC1A4
+        const u64 tileSize = 4 * (format == Formats::ETC1 ? 8 : 16);
+        return tileCount * tileSize;
+    }
+
+    default:
+        Helpers::panic("[PICA] Attempted to get size of invalid texture type");
+    }
+}