vdp1_command_pipeline.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_VDP1_COMMAND_PIPELINE_H__
# define __JO_VDP1_COMMAND_PIPELINE_H__
 
/*
** VDP1 VRAM layout:
**
** 0x00000 : jump command to the table to draw
** 0x00020 : command table A
** 0x08000 : command table B
** 0x10000 : textures (JO_VDP1_TEXTURE_DEF_BASE_ADDRESS)
** 0x7E700 : gouraud tables of the clipped and subdivided 3D polygons
** 0x7FF00 : gouraud tables used for 3D lighting
*/

#ifndef JO_VDP1_MAX_COMMANDS
# define JO_VDP1_MAX_COMMANDS               (1000)
#endif

typedef struct
{
    unsigned short          ctrl;
    unsigned short          link;
    unsigned short          pmod;
    unsigned short          colr;
    unsigned short          srca;
    unsigned short          size;
    short                   xa;
    short                   ya;
    short                   xb;
    short                   yb;
    short                   xc;
    short                   yc;
    short                   xd;
    short                   yd;
    unsigned short          grda;
    unsigned short          reserved;
}                           jo_vdp1_command;

# define JO_VDP1_CMD_NORMAL_SPRITE          (0x0000)
# define JO_VDP1_CMD_SCALED_SPRITE          (0x0001)
# define JO_VDP1_CMD_DISTORTED_SPRITE       (0x0002)
# define JO_VDP1_CMD_POLYGON                (0x0004)
# define JO_VDP1_CMD_POLYLINE               (0x0005)
# define JO_VDP1_CMD_LINE                   (0x0006)
# define JO_VDP1_CMD_USER_CLIP              (0x0008)
# define JO_VDP1_CMD_SYSTEM_CLIP            (0x0009)
# define JO_VDP1_CMD_LOCAL_COORD            (0x000A)
# define JO_VDP1_CMD_SKIP_ASSIGN            (0x5000)
# define JO_VDP1_CMD_END                    (0x8000)
 
/*
** Drawing function (low bits of the "direction" attribute)
*/
# define JO_VDP1_FUNCTION_SPRITE            (1)
# define JO_VDP1_FUNCTION_TEXTURE           (2)
# define JO_VDP1_FUNCTION_POLYGON           (4)
# define JO_VDP1_FUNCTION_POLYLINE          (5)
# define JO_VDP1_FUNCTION_LINE              (6)
# define JO_VDP1_FUNCTION_USER_CLIP         (8)
# define JO_VDP1_FUNCTION_SYSTEM_CLIP       (9)
# define JO_VDP1_FUNCTION_LOCAL_COORDINATES (10)

# define JO_VDP1_DIRECTION_FUNCTION_MASK    (0x0f)
# define JO_VDP1_DIRECTION_FLIP_MASK        (0x30)
# define JO_VDP1_H_FLIP                     (0x10)
 
/*
** Draw mode (CMDPMOD register layout)
*/
# define JO_VDP1_MSB_ON                     (1 << 15)
# define JO_VDP1_HIGH_SPEED_SHRINK          (1 << 12)
# define JO_VDP1_NO_WINDOW                  (0)
# define JO_VDP1_WINDOW_IN                  (2 << 9)
# define JO_VDP1_WINDOW_OUT                 (3 << 9)
# define JO_VDP1_MESH                       (1 << 8)
# define JO_VDP1_NO_MESH                    (0)
# define JO_VDP1_END_CODE_DISABLE           (1 << 7)
# define JO_VDP1_RGB_END_CODE               (0x7FFF)
# define JO_VDP1_TRANSPARENT_PIXEL_DISABLE  (1 << 6)
# define JO_VDP1_COLOR_MODE_16_BANK         (0 << 3)
# define JO_VDP1_COLOR_MODE_16_LOOKUP       (1 << 3)
# define JO_VDP1_COLOR_MODE_64_BANK         (2 << 3)
# define JO_VDP1_COLOR_MODE_128_BANK        (3 << 3)
# define JO_VDP1_COLOR_MODE_256_BANK        (4 << 3)
# define JO_VDP1_COLOR_MODE_RGB             (5 << 3)
# define JO_VDP1_COLOR_MODE_MASK            (7 << 3)
# define JO_VDP1_COLOR_CALC_REPLACE         (0)
# define JO_VDP1_COLOR_CALC_SHADOW          (1)
# define JO_VDP1_COLOR_CALC_HALF_LUMINANCE  (2)
# define JO_VDP1_COLOR_CALC_HALF_TRANSPARENT (3)
# define JO_VDP1_COLOR_CALC_GOURAUD         (4)
# define JO_VDP1_COLOR_CALC_MASK            (7)
# define JO_VDP1_NO_GOURAUD                 (0)
# define JO_VDP1_NO_PALETTE                 (0)
 
/*
** Texture size: bytes = width * height * 4 >> shift
*/
# define JO_VDP1_TEXTURE_SIZE_SHIFT_16_COLORS       (3)
# define JO_VDP1_TEXTURE_SIZE_SHIFT_256_COLORS      (2)
# define JO_VDP1_TEXTURE_SIZE_SHIFT_32K_COLORS      (1)

# define JO_VDP1_OPTION_USE_TEXTURE         (1 << 2)
 
/*
** Direction attribute: drawing function | flip | (options << 16) | (draw mode bits << 24)
*/
# define JO_VDP1_SPRITE_NO_FLIP             ((0) | JO_VDP1_FUNCTION_TEXTURE | (JO_VDP1_OPTION_USE_TEXTURE << 16))
# define JO_VDP1_SPRITE_H_FLIP              ((1 << 4) | JO_VDP1_FUNCTION_TEXTURE | (JO_VDP1_OPTION_USE_TEXTURE << 16))
# define JO_VDP1_SPRITE_V_FLIP              ((1 << 5) | JO_VDP1_FUNCTION_TEXTURE | (JO_VDP1_OPTION_USE_TEXTURE << 16))
# define JO_VDP1_SPRITE_HV_FLIP             ((3 << 4) | JO_VDP1_FUNCTION_TEXTURE | (JO_VDP1_OPTION_USE_TEXTURE << 16))
# define JO_VDP1_POLYGON                    (JO_VDP1_FUNCTION_POLYGON | ((JO_VDP1_END_CODE_DISABLE | JO_VDP1_TRANSPARENT_PIXEL_DISABLE) << 24))
# define JO_VDP1_POLYLINE                   (JO_VDP1_FUNCTION_POLYLINE | ((JO_VDP1_END_CODE_DISABLE | JO_VDP1_TRANSPARENT_PIXEL_DISABLE) << 24))
# define JO_VDP1_LINE                       (JO_VDP1_FUNCTION_LINE | ((JO_VDP1_END_CODE_DISABLE | JO_VDP1_TRANSPARENT_PIXEL_DISABLE) << 24))

# define JO_VDP1_DIRECTION_COMMAND(DIRECTION)   ((DIRECTION) & (JO_VDP1_DIRECTION_FUNCTION_MASK | JO_VDP1_DIRECTION_FLIP_MASK))
# define JO_VDP1_DIRECTION_OPTIONS(DIRECTION)   (((DIRECTION) >> 16) & 0x1c)
# define JO_VDP1_DIRECTION_DRAW_MODE(DIRECTION) (((DIRECTION) >> 24) & (JO_VDP1_END_CODE_DISABLE | JO_VDP1_TRANSPARENT_PIXEL_DISABLE))

typedef struct
{
    unsigned short          texture_id;     // Sprite id (__jo_sprite_def index)
    unsigned short          draw_mode;      // JO_VDP1_COLOR_MODE_xxx | JO_VDP1_COLOR_CALC_xxx | ...
    unsigned short          color;          // RGB color or palette
    unsigned short          gouraud_table;  // Gouraud table address / 8
    unsigned short          direction;      // JO_VDP1_FUNCTION_xxx | flip
}                           jo_vdp1_sprite_attribute;

# define JO_VDP1_SPRITE_ATTRIBUTE(TEXTURE, COLOR, GOURAUD, DRAW_MODE, DIRECTION) \
    {(TEXTURE), (DRAW_MODE) | JO_VDP1_DIRECTION_DRAW_MODE(DIRECTION), (COLOR), (GOURAUD), JO_VDP1_DIRECTION_COMMAND(DIRECTION)}

typedef struct
{
    jo_fixed                x;
    jo_fixed                y;
    jo_fixed                z;
    jo_fixed                scale_x;        // Scale (negative value: perspective scale)
    jo_fixed                scale_y;        // Vertical scale (only for __jo_vdp1_draw_sprite_hv())
}                           jo_vdp1_sprite_position;

# define JO_VDP1_LIGHT_TABLE_OFFSET         (0x7FF00)
# define JO_VDP1_CLIP_GOURAUD_TABLE_OFFSET  (0x7E700)
# define JO_VDP1_CLIP_GOURAUD_TABLE_COUNT   (768)

typedef struct
{
    short                   left;
    short                   top;
    short                   right;
    short                   bottom;
    short                   center_x;
    short                   center_y;
    jo_fixed                   zlimit;
    unsigned short          clip_mode;      // Draw mode bits of the 3D polygons: JO_VDP1_WINDOW_IN (clipped to the window), 0
}                           jo_vdp1_window;

# define JO_VDP1_WINDOW_COUNT       (3)
extern jo_vdp1_window       __jo_vdp1_windows[JO_VDP1_WINDOW_COUNT];

extern int                  __jo_vdp1_current_window;

extern jo_fixed                __jo_vdp1_projection_distance;

extern unsigned short       __jo_vdp1_display_level;

void                        __jo_vdp1_init(void);

void                        __jo_vdp1_end_frame(void);

void                        __jo_vdp1_vblank(void);

unsigned int                __jo_vdp1_frame_tag(void);

bool                        __jo_vdp1_displayed_frame_changed(unsigned int * const tag);

void                        jo_vdp1_redraw_last_frame(void);

jo_vdp1_command             *__jo_vdp1_add_command(const jo_fixed z);

jo_vdp1_command             *__jo_vdp1_reserve_commands(const unsigned int count, unsigned short **keys, unsigned int *reserved);

unsigned short              *__jo_vdp1_commit_commands_without_window(const unsigned int used);

void                        __jo_vdp1_commit_commands(const unsigned int used);

# define JO_VDP1_MAX_KEY            (0xffff)

extern int                  __jo_vdp1_depth_bias;

static  __jo_force_inline unsigned short __jo_vdp1_sort_key(const jo_fixed z)
{
    int                     key;
 
    key = JO_FIXED_TO_INT(z) + __jo_vdp1_depth_bias;
    if (key < 0)
        return (0);
    if (key > JO_VDP1_MAX_KEY)
        return (JO_VDP1_MAX_KEY);
    return ((unsigned short)key);
}

extern short                __jo_vdp1_system_clip_right;

extern short                __jo_vdp1_system_clip_bottom;

bool                        __jo_vdp1_set_attribute(jo_vdp1_command *cmd, const jo_vdp1_sprite_attribute *attr);

extern jo_fixed             __jo_vdp1_near_z;

extern bool                 __jo_vdp1_wireframe;

static  __jo_force_inline void __jo_vdp1_update_near_clip(void)
{
    // Variable shift: computed once instead of for each sprite (the SH-2 can only shift by 1, 2, 8 or 16 bits)
    __jo_vdp1_near_z = __jo_vdp1_projection_distance >> (__jo_vdp1_display_level ? __jo_vdp1_display_level : 1);
}

static  __jo_force_inline jo_fixed __jo_vdp1_near_clip(void)
{
    return (__jo_vdp1_near_z);
}

bool                        __jo_vdp1_draw_sprite(const jo_vdp1_sprite_position * const pos, const jo_vdp1_sprite_attribute * const attr, const jo_angle angle);

bool                        __jo_vdp1_draw_sprite_hv(const jo_vdp1_sprite_position * const pos, const jo_vdp1_sprite_attribute * const attr, const jo_angle angle);

bool                        __jo_vdp1_draw_sprite_4p(const jo_pos2D_fixed * const points, const jo_fixed z, const jo_vdp1_sprite_attribute * const attr);

bool                        __jo_vdp1_write_sprite_4p(jo_vdp1_command * const cmd, const jo_pos2D_fixed * const points, const jo_fixed z,
                                                      const jo_vdp1_sprite_attribute * const attr, const int window);

void                        __jo_sprite_attributes_of(jo_vdp1_sprite_attribute *attr, const int sprite_id, const jo_sprite_attributes * const state);

bool                        __jo_vdp1_draw_sprite_3d(const jo_vdp1_sprite_position * const pos, const jo_vdp1_sprite_attribute * const attr, const jo_angle angle);

void                        __jo_vdp1_set_window(const short left, const short top, const short right, const short bottom,
                                                 const short zlimit, const short center_x, const short center_y);

static  __jo_force_inline void __jo_vdp1_select_window(const int window)
{
    __jo_vdp1_current_window = (window >= 0 && window < JO_VDP1_WINDOW_COUNT) ? window : 0;
}

int                         jo_vdp1_command_count(void);

int                         __jo_vdp1_frame_command_count(void);

int                         jo_vdp1_command_max(void);
 
#endif /* !__JO_VDP1_COMMAND_PIPELINE_H__ */
 
/*
** END OF FILE
*/