add MainBatch & refactor ModelBatch, Batch3D

src/graphics/render/MainBatch.hpp

@@ -0,0 +1,61 @@
+#pragma once
+
+#include <memory>
+#include <stdint.h>
+#include <glm/glm.hpp>
+
+#include "maths/UVRegion.hpp"
+
+class Mesh;
+class Texture;
+
+class MainBatch {
+    std::unique_ptr<float[]> const buffer;
+    size_t const capacity;
+    size_t index;
+
+    UVRegion region {0.0f, 0.0f, 1.0f, 1.0f};
+
+    std::unique_ptr<Mesh> mesh;
+    std::unique_ptr<Texture> blank;
+
+    const Texture* texture = nullptr;
+public:
+    /// xyz, uv, color, compressed lights
+    static inline constexpr uint VERTEX_SIZE = 9;
+
+    MainBatch(size_t capacity);
+
+    ~MainBatch();
+
+    void prepare(int vertices);
+    void setTexture(const Texture* texture);
+    void setTexture(const Texture* texture, const UVRegion& region);
+    void flush();
+
+    inline void vertex(
+        glm::vec3 pos, glm::vec2 uv, glm::vec4 light, glm::vec3 tint
+    ) {
+        float* buffer = this->buffer.get();
+        buffer[index++] = pos.x;
+        buffer[index++] = pos.y;
+        buffer[index++] = pos.z;
+        buffer[index++] = uv.x * region.getWidth() + region.u1;
+        buffer[index++] = uv.y * region.getHeight() + region.v1;
+        buffer[index++] = tint.x;
+        buffer[index++] = tint.y;
+        buffer[index++] = tint.z;
+
+        union {
+            float floating;
+            uint32_t integer;
+        } compressed;
+
+        compressed.integer  = (static_cast<uint32_t>(light.r * 255) & 0xff) << 24;
+        compressed.integer |= (static_cast<uint32_t>(light.g * 255) & 0xff) << 16;
+        compressed.integer |= (static_cast<uint32_t>(light.b * 255) & 0xff) << 8;
+        compressed.integer |= (static_cast<uint32_t>(light.a * 255) & 0xff);
+
+        buffer[index++] = compressed.floating;
+    }
+};