add ModelBatch

src/graphics/render/ModelBatch.hpp

@@ -0,0 +1,84 @@
+#ifndef GRAPHICS_RENDER_MODEL_BATCH_HPP_
+#define GRAPHICS_RENDER_MODEL_BATCH_HPP_
+
+#include <memory>
+#include <vector>
+#include <glm/glm.hpp>
+
+class Mesh;
+class Texture;
+
+struct DecomposedMat4 {
+    glm::vec3 scale;
+    glm::mat3 rotation;
+    glm::vec3 translation;
+    glm::vec3 skew;
+    glm::vec4 perspective;
+};
+#include <iostream>
+class ModelBatch {
+    std::unique_ptr<float[]> buffer;
+    size_t capacity;
+    size_t index;
+
+    std::unique_ptr<Mesh> mesh;
+    std::unique_ptr<Texture> blank;
+
+    glm::mat4 combined;
+    std::vector<glm::mat4> matrices;
+
+    DecomposedMat4 decomposed {};
+
+    inline void vertex(
+        glm::vec3 pos, glm::vec2 uv, glm::vec4 color
+    ) {
+        float* buffer = this->buffer.get();
+        pos = combined * glm::vec4(pos, 1.0f);
+        buffer[index++] = pos.x;
+        buffer[index++] = pos.y;
+        buffer[index++] = pos.z;
+        buffer[index++] = uv.x;
+        buffer[index++] = uv.y;
+
+        union {
+            float floating;
+            uint32_t integer;
+        } compressed;
+
+        compressed.integer = (static_cast<uint32_t>(color.r * 255) & 0xff) << 24;
+        compressed.integer |= (static_cast<uint32_t>(color.g * 255) & 0xff) << 16;
+        compressed.integer |= (static_cast<uint32_t>(color.b * 255) & 0xff) << 8;
+        compressed.integer |= (static_cast<uint32_t>(color.a * 255) & 0xff);
+
+        buffer[index++] = compressed.floating;
+    }
+
+    inline void plane(glm::vec3 pos, glm::vec3 right, glm::vec3 up, glm::vec3 norm) {
+        norm = decomposed.rotation * norm;
+        glm::vec4 color {norm.x, norm.y, norm.z, 0.0f};
+        color.r = glm::max(0.0f, color.r);
+        color.g = glm::max(0.0f, color.g);
+        color.b = glm::max(0.0f, color.b);
+
+        vertex(pos-right-up, {0,0}, color);
+        vertex(pos+right-up, {1,0}, color);
+        vertex(pos+right+up, {1,1}, color);
+
+        vertex(pos-right-up, {0,0}, color);
+        vertex(pos+right+up, {1,1}, color);
+        vertex(pos-right+up, {0,1}, color);
+    }
+public:
+    ModelBatch(size_t capacity);
+    ~ModelBatch();
+
+    void pushMatrix(glm::mat4 matrix);
+    void popMatrix();
+
+    void box(glm::vec3 pos, glm::vec3 size);
+
+    void test(glm::vec3 pos, glm::vec3 size);
+    void flush();
+};
+
+#endif // GRAPHICS_RENDER_MODEL_BATCH_HPP_