// Copyright (c) 2025 Dominic Masters
// 
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

#pragma once
#include "display/display.h"

typedef enum {
  #if DISPLAY_SDL2
    MESH_PRIMITIVE_TRIANGLES = GL_TRIANGLES,
    MESH_PRIMITIVE_LINES = GL_LINES,
    MESH_PRIMITIVE_POINTS = GL_POINTS,
  #endif
} meshprimitivetype_t;

#define MESH_VERTEX_COLOR_SIZE 4
#define MESH_VERTEX_UV_SIZE 2
#define MESH_VERTEX_POS_SIZE 3

typedef struct {
  #if DISPLAY_SDL2
    GLubyte color[MESH_VERTEX_COLOR_SIZE];
    GLfloat uv[MESH_VERTEX_UV_SIZE];
    GLfloat pos[MESH_VERTEX_POS_SIZE];
  #endif
} meshvertex_t;

typedef struct {
  const meshvertex_t *vertices;
  int32_t vertexCount;
  meshprimitivetype_t primitiveType;
} mesh_t;

/**
 * Initializes a mesh.
 * 
 * @param mesh The mesh to initialize.
 * @param primitiveType The OpenGL primitive type (e.g., GL_TRIANGLES).
 * @param vertexCount The number of vertices in the mesh.
 * @param vertices The vertex data for the mesh.
 */
void meshInit(
  mesh_t *mesh,
  const meshprimitivetype_t primitiveType,
  const int32_t vertexCount,
  const meshvertex_t *vertices
);

/**
 * Draws a mesh.
 * 
 * @param mesh The mesh to draw.
 * @param vertexOffset The offset in the vertex array to start drawing from.
 * @param vertexCount The number of vertices to draw. If -1, draws all vertices.
 */
void meshDraw(
  const mesh_t *mesh,
  const int32_t vertexOffset,
  const int32_t vertexCount
);

/**
 * Disposes a mesh.
 * 
 * @param mesh The mesh to dispose.
 */
void meshDispose(mesh_t *mesh);