src/ascension/mesh.h

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * Copyright 2023 Mike Becker. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 */

#ifndef ASCENSION_MESH_H
#define ASCENSION_MESH_H

#include "datatypes.h"

enum AscMeshType {
    ASC_MESH_2D,
    ASC_MESH_2D_COLORED,
    ASC_MESH_3D,
    ASC_MESH_3D_COLORED,
};

typedef struct asc_mesh_s {
    // TODO: for batched rendering, VAO and VBO must not be part of the mesh
    unsigned vbo;
    unsigned vao;
    enum AscMeshType type;
    unsigned vtx_count;
    unsigned vtx_data_size;
    float *vtx_data;
} AscMesh;

typedef struct asc_vertex2d {
    asc_vec2f pos;
    asc_vec2f uv;
} asc_vertex2d;

typedef struct asc_vertex2d_col {
    asc_vec2f pos;
    asc_vec2f uv;
    asc_col4f color;
} asc_vertex2d_col;

typedef struct asc_vertex3d {
    asc_vec3f pos;
    asc_vec2f uv;
} asc_vertex3d;

typedef struct asc_vertex3d_col {
    asc_vec3f pos;
    asc_vec2f uv;
    asc_col4f color;
} asc_vertex3d_col;


void asc_mesh_destroy(AscMesh *mesh);

struct asc_mesh_init_plane_2d_args {
    asc_vec2f size;
    asc_vec2f uv_offset;
    asc_vec2f uv_scale;
};

/**
 * Write a 2D plane to the specified mesh data.
 *
 * @param mesh the mesh to initialize
 * @param ... the initialization parameters
 */
#define asc_mesh_plane_2d(mesh, ...) asc_mesh_init_plane_2d(mesh, (struct asc_mesh_init_plane_2d_args){__VA_ARGS__})

void asc_mesh_init_plane_2d(AscMesh *mesh, struct asc_mesh_init_plane_2d_args args);


// TODO: replace below functions with a batched rendering implementation

/**
 * Allocates VBO and VAO for one or more meshes.
 *
 * @param mesh pointer to a mesh or an array of meshes
 * @param count the number of meshes (maximum 32)
 */
void asc_mesh_allocate_buffers(AscMesh *mesh, unsigned count);

/**
 * Frees VBO and VAO for one or more meshes.
 *
 * @param mesh pointer to a mesh or an array of meshes
 * @param count the number of meshes (maximum 32)
 */
void asc_mesh_free_buffers(AscMesh *mesh, unsigned count);

/**
 * Draws the mesh as a triangle strip.
 *
 * @param mesh the mesh to draw
 */
void asc_mesh_draw_triangle_strip(const AscMesh *mesh);

#endif //ASCENSION_MESH_H