software_renderer.h

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/*
** Jo Sega Saturn Engine
** Copyright (c) 2012-2026, Johannes Fetz (johannesfetz@gmail.com)
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are met:
**     * Redistributions of source code must retain the above copyright
**       notice, this list of conditions and the following disclaimer.
**     * 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.
**     * Neither the name of the Johannes Fetz nor the
**       names of its contributors may be used to endorse or promote products
**       derived from this software without specific prior written permission.
**
** 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 Johannes Fetz 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 POSSIBILITY OF SUCH DAMAGE.
*/
 
#ifndef __JO_SOFTWARE_RENDERER_H__
# define __JO_SOFTWARE_RENDERER_H__
 
#ifdef JO_COMPILE_WITH_SOFTWARE_RENDERER_SUPPORT
 
/*
 ██████╗ ██████╗ ██████╗ ███████╗
██╔════╝██╔═══██╗██╔══██╗██╔════╝
██║     ██║   ██║██████╔╝█████╗
██║     ██║   ██║██╔══██╗██╔══╝
╚██████╗╚██████╔╝██║  ██║███████╗
 ╚═════╝ ╚═════╝ ╚═╝  ╚═╝╚══════╝
*/
 
/*
   Jo Engine Software Rendering XYZ axes
 
           Z-
          /
         /
        0------> X+ (width)
       /|
      / |
     Z+ V
        Y+ (height)
*/

typedef enum
{
    JO_SR_DRAW_TEXTURED     = (1 << 0),
    JO_SR_DRAW_FLAT         = (1 << 1),
    JO_SR_DRAW_WIREFRAME    = (1 << 2)
}                                           jo_software_renderer_draw_mode;

typedef enum
{
    JO_SR_BACK_FACE_CULLING     = (1 << 0),
    JO_SR_FRONT_FACE_CULLING    = (1 << 1),
    JO_SR_NO_FACE_CULLING       = (1 << 2)
}                                           jo_software_renderer_face_culling_mode;

typedef enum
{
    JO_SR_DEPTH_IGNORE                      = (1 << 0),
    JO_SR_DEPTH_LESS                        = (1 << 1),
    JO_SR_DEPTH_LESS_OR_EQUAL               = (1 << 2),
    JO_SR_DEPTH_GREATER_OR_EQUAL            = (1 << 3),
    JO_SR_DEPTH_GREATER                     = (1 << 4),
    JO_SR_DEPTH_NOT_EQUAL                   = (1 << 5),
    JO_SR_DEPTH_EQUAL                       = (1 << 6)
}                                           jo_software_renderer_depth_mode;

typedef struct
{
    jo_size                                 clipping_size;
    int                                     sprite_id;
    jo_fixed                                *depth_buffer;
    unsigned int                            depth_buffer_dword_size;
    jo_color                                *color_buffer;
    unsigned int                            color_buffer_size;
    void                                    *vram;
    jo_size                                 vram_size;
    jo_software_renderer_depth_mode         depth_mode_testing;
    jo_software_renderer_draw_mode          draw_mode;
    jo_software_renderer_face_culling_mode  face_culling_mode;
}                                           jo_software_renderer_gfx;

typedef struct
{
    jo_vector4_fixed                        pos;
    jo_vector2_fixed                        uv_texture_mapping;
    jo_color                                color;
}                                           jo_software_renderer_vertex;

jo_software_renderer_gfx                    *jo_software_renderer_create_ex(unsigned short width, unsigned short height, const jo_scroll_screen screen, const bool enable_zbuffer);

static __jo_force_inline jo_software_renderer_gfx   *jo_software_renderer_create(unsigned short width, unsigned short height, const jo_scroll_screen screen)
{
    return (jo_software_renderer_create_ex(width, height, screen, true));
}

void                                        jo_software_renderer_free(jo_software_renderer_gfx * const gfx);

void                                        jo_software_renderer_flush(jo_software_renderer_gfx * const gfx);
 
/*
██████╗  █████╗ ███████╗██╗ ██████╗    ██████╗ ██████╗  █████╗ ██╗    ██╗██╗███╗   ██╗ ██████╗
██╔══██╗██╔══██╗██╔════╝██║██╔════╝    ██╔══██╗██╔══██╗██╔══██╗██║    ██║██║████╗  ██║██╔════╝
██████╔╝███████║███████╗██║██║         ██║  ██║██████╔╝███████║██║ █╗ ██║██║██╔██╗ ██║██║  ███╗
██╔══██╗██╔══██║╚════██║██║██║         ██║  ██║██╔══██╗██╔══██║██║███╗██║██║██║╚██╗██║██║   ██║
██████╔╝██║  ██║███████║██║╚██████╗    ██████╔╝██║  ██║██║  ██║╚███╔███╔╝██║██║ ╚████║╚██████╔╝
╚═════╝ ╚═╝  ╚═╝╚══════╝╚═╝ ╚═════╝    ╚═════╝ ╚═╝  ╚═╝╚═╝  ╚═╝ ╚══╝╚══╝ ╚═╝╚═╝  ╚═══╝ ╚═════╝
*/

void                                        jo_software_renderer_clear(const jo_software_renderer_gfx * const gfx, const jo_color color);

void                                        jo_software_renderer_draw_pixel2D(const jo_software_renderer_gfx * const gfx, const jo_fixed x, const jo_fixed y, const jo_color color);

void                                        jo_software_renderer_draw_pixel3D(const jo_software_renderer_gfx * const gfx, const jo_fixed x, const jo_fixed y, const jo_fixed z, const jo_color color);

void                                        jo_software_renderer_draw_line3D(const jo_software_renderer_gfx * const gfx,
                                                                           jo_fixed x0, jo_fixed y0, jo_fixed z0,
                                                                           jo_fixed x1, jo_fixed y1, jo_fixed z1,
                                                                           const jo_color color0, const jo_color color1);
 
/*
████████╗██████╗ ██╗ █████╗ ███╗   ██╗ ██████╗ ██╗     ███████╗
╚══██╔══╝██╔══██╗██║██╔══██╗████╗  ██║██╔════╝ ██║     ██╔════╝
   ██║   ██████╔╝██║███████║██╔██╗ ██║██║  ███╗██║     █████╗
   ██║   ██╔══██╗██║██╔══██║██║╚██╗██║██║   ██║██║     ██╔══╝
   ██║   ██║  ██║██║██║  ██║██║ ╚████║╚██████╔╝███████╗███████╗
   ╚═╝   ╚═╝  ╚═╝╚═╝╚═╝  ╚═╝╚═╝  ╚═══╝ ╚═════╝ ╚══════╝╚══════╝
*/

typedef struct
{
    jo_software_renderer_vertex             v0;
    jo_software_renderer_vertex             v1;
    jo_software_renderer_vertex             v2;
    int                                     sprite_id;
}                                           jo_software_renderer_triangle;
 
void                                        jo_software_renderer_draw_triangle(const jo_software_renderer_gfx * const gfx,
                                                                               const jo_software_renderer_triangle * const triangle,
                                                                               const jo_matrix * const transform_matrix);

static __jo_force_inline void               jo_software_renderer_draw_triangle_wireframe(const jo_software_renderer_gfx * const gfx, const jo_software_renderer_triangle * const triangle)
{
    jo_software_renderer_draw_line3D(gfx,
                                     triangle->v0.pos.x, triangle->v0.pos.y, triangle->v0.pos.z,
                                     triangle->v1.pos.x, triangle->v1.pos.y, triangle->v1.pos.z,
                                     triangle->v0.color, triangle->v1.color);
    jo_software_renderer_draw_line3D(gfx,
                                     triangle->v1.pos.x, triangle->v1.pos.y, triangle->v1.pos.z,
                                     triangle->v2.pos.x, triangle->v2.pos.y, triangle->v2.pos.z,
                                     triangle->v1.color, triangle->v2.color);
    jo_software_renderer_draw_line3D(gfx,
                                     triangle->v2.pos.x, triangle->v2.pos.y, triangle->v2.pos.z,
                                     triangle->v0.pos.x, triangle->v0.pos.y, triangle->v0.pos.z,
                                     triangle->v2.color, triangle->v0.color);
}
 
#endif // JO_COMPILE_WITH_SOFTWARE_RENDERER_SUPPORT
 
#endif /* !__JO_SOFTWARE_RENDERER_H__ */
 
/*
** END OF FILE
*/