/*
 * Copyright 2017, Blender Foundation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * Contributor(s): Antonio Vazquez
 *
 */

/** \file blender/draw/engines/gpencil/gpencil_engine.h
 *  \ingroup draw
 */

#ifndef __GPENCIL_ENGINE_H__
#define __GPENCIL_ENGINE_H__

#include "GPU_batch.h"

struct tGPspoint;
struct bGPDstroke;
struct ModifierData;
struct GPENCIL_Data;
struct GPENCIL_StorageList;
struct Object;
struct MaterialGPencilStyle;
struct RenderEngine;
struct RenderLayer;

#define GPENCIL_CACHE_BLOCK_SIZE 8
#define GPENCIL_MAX_SHGROUPS 65536
#define GPENCIL_MIN_BATCH_SLOTS_CHUNK 16

#define GPENCIL_COLOR_SOLID   0
#define GPENCIL_COLOR_TEXTURE 1
#define GPENCIL_COLOR_PATTERN 2

#define GP_SIMPLIFY(scene) ((scene->r.simplify_gpencil & SIMPLIFY_GPENCIL_ENABLE))
#define GP_SIMPLIFY_ONPLAY(playing) (((playing == true) && (scene->r.simplify_gpencil & SIMPLIFY_GPENCIL_ON_PLAY)) || ((scene->r.simplify_gpencil & SIMPLIFY_GPENCIL_ON_PLAY) == 0))
#define GP_SIMPLIFY_FILL(scene, playing) ((GP_SIMPLIFY_ONPLAY(playing) && (GP_SIMPLIFY(scene)) && (scene->r.simplify_gpencil & SIMPLIFY_GPENCIL_FILL)))
#define GP_SIMPLIFY_MODIF(scene, playing) ((GP_SIMPLIFY_ONPLAY(playing) && (GP_SIMPLIFY(scene)) && (scene->r.simplify_gpencil & SIMPLIFY_GPENCIL_MODIFIER)))
#define GP_SIMPLIFY_FX(scene, playing) ((GP_SIMPLIFY_ONPLAY(playing) && (GP_SIMPLIFY(scene)) && (scene->r.simplify_gpencil & SIMPLIFY_GPENCIL_FX)))

#define GP_IS_CAMERAVIEW ((rv3d != NULL) && (rv3d->persp == RV3D_CAMOB && v3d->camera))

 /* *********** OBJECTS CACHE *********** */

 /* used to save gpencil object data for drawing */
typedef struct tGPencilObjectCache {
	struct Object *ob;
	struct bGPdata *gpd;
	int init_grp, end_grp;
	int idx;  /*original index, can change after sort */

	/* effects */
	bool has_fx;
	ListBase shader_fx;
	float pixfactor;
	DRWShadingGroup *fx_wave_sh;
	DRWShadingGroup *fx_blur_sh;
	DRWShadingGroup *fx_colorize_sh;
	DRWShadingGroup *fx_pixel_sh;
	DRWShadingGroup *fx_rim_sh;
	DRWShadingGroup *fx_shadow_sh;
	DRWShadingGroup *fx_glow_sh;
	DRWShadingGroup *fx_swirl_sh;
	DRWShadingGroup *fx_flip_sh;
	DRWShadingGroup *fx_light_sh;

	float loc[3];
	float obmat[4][4];
	float zdepth;  /* z-depth value to sort gp object */
	bool is_dup_ob;  /* flag to tag duplicate objects */
	bool is_dup_data; /* other object uses datablock already */
	int  data_idx;    /* derived data index */
} tGPencilObjectCache;

  /* *********** LISTS *********** */
typedef struct GPENCIL_shgroup {
	int s_clamp;
	int stroke_style;
	int color_type;
	int mode;
	int texture_mix;
	int texture_flip;
	int texture_clamp;
	int fill_style;
	int keep_size;
	float obj_scale;
	struct DRWShadingGroup *shgrps_fill;
	struct DRWShadingGroup *shgrps_stroke;
} GPENCIL_shgroup;

typedef struct GPENCIL_Storage {
	int shgroup_id; /* total elements */
	float unit_matrix[4][4];
	int stroke_style;
	int color_type;
	int mode;
	int xray;
	int keep_size;
	float obj_scale;
	float pixfactor;
	bool is_playing;
	bool is_render;
	bool is_mat_preview;
	bool reset_cache;
	bool buffer_stroke;
	bool buffer_fill;
	const float *pixsize;
	float render_pixsize;
	int tonemapping;
	short multisamples;

	/* simplify settings*/
	bool simplify_fill;
	bool simplify_modif;
	bool simplify_fx;

	/* Render Matrices and data */
	float persmat[4][4], persinv[4][4];
	float viewmat[4][4], viewinv[4][4];
	float winmat[4][4], wininv[4][4];
	float view_vecs[2][4]; /* vec4[2] */

	Object *camera; /* camera pointer for render mode */
} GPENCIL_Storage;

typedef struct GPENCIL_StorageList {
	struct GPENCIL_Storage *storage;
	struct g_data *g_data;
	struct GPENCIL_shgroup *shgroups;
} GPENCIL_StorageList;

typedef struct GPENCIL_PassList {
	struct DRWPass *stroke_pass;
	struct DRWPass *edit_pass;
	struct DRWPass *drawing_pass;
	struct DRWPass *mix_pass;
	struct DRWPass *mix_pass_noblend;
	struct DRWPass *background_pass;
	struct DRWPass *paper_pass;
	struct DRWPass *grid_pass;

	/* effects */
	struct DRWPass *fx_shader_pass;
	struct DRWPass *fx_shader_pass_blend;

} GPENCIL_PassList;

typedef struct GPENCIL_FramebufferList {
	struct GPUFrameBuffer *main;
	struct GPUFrameBuffer *temp_fb_a;
	struct GPUFrameBuffer *temp_fb_b;
	struct GPUFrameBuffer *temp_fb_fx;
	struct GPUFrameBuffer *background_fb;

	struct GPUFrameBuffer *multisample_fb;
} GPENCIL_FramebufferList;

typedef struct GPENCIL_TextureList {
	struct GPUTexture *texture;

	/* multisample textures */
	struct GPUTexture *multisample_color;
	struct GPUTexture *multisample_depth;

} GPENCIL_TextureList;

typedef struct GPENCIL_Data {
	void *engine_type; /* Required */
	struct GPENCIL_FramebufferList *fbl;
	struct GPENCIL_TextureList *txl;
	struct GPENCIL_PassList *psl;
	struct GPENCIL_StorageList *stl;

	/* render textures */
	struct GPUTexture *render_depth_tx;
	struct GPUTexture *render_color_tx;

} GPENCIL_Data;

/* *********** STATIC *********** */
typedef struct g_data {
	struct DRWShadingGroup *shgrps_edit_point;
	struct DRWShadingGroup *shgrps_edit_line;
	struct DRWShadingGroup *shgrps_drawing_stroke;
	struct DRWShadingGroup *shgrps_drawing_fill;
	struct DRWShadingGroup *shgrps_grid;

	int gp_cache_used; /* total objects in cache */
	int gp_cache_size; /* size of the cache */
	struct tGPencilObjectCache *gp_object_cache;

	int session_flag;

} g_data; /* Transient data */

/* flags for fast drawing support */
typedef enum eGPsession_Flag {
	GP_DRW_PAINT_HOLD     = (1 << 0),
	GP_DRW_PAINT_IDLE     = (1 << 1),
	GP_DRW_PAINT_FILLING  = (1 << 2),
	GP_DRW_PAINT_READY    = (1 << 3),
	GP_DRW_PAINT_PAINTING = (1 << 4),
} eGPsession_Flag;

typedef struct GPENCIL_e_data {
	/* general drawing shaders */
	struct GPUShader *gpencil_fill_sh;
	struct GPUShader *gpencil_stroke_sh;
	struct GPUShader *gpencil_point_sh;
	struct GPUShader *gpencil_edit_point_sh;
	struct GPUShader *gpencil_line_sh;
	struct GPUShader *gpencil_drawing_fill_sh;
	struct GPUShader *gpencil_fullscreen_sh;
	struct GPUShader *gpencil_simple_fullscreen_sh;
	struct GPUShader *gpencil_background_sh;
	struct GPUShader *gpencil_paper_sh;

	/* effects */
	struct GPUShader *gpencil_fx_blur_sh;
	struct GPUShader *gpencil_fx_colorize_sh;
	struct GPUShader *gpencil_fx_flip_sh;
	struct GPUShader *gpencil_fx_glow_prepare_sh;
	struct GPUShader *gpencil_fx_glow_resolve_sh;
	struct GPUShader *gpencil_fx_light_sh;
	struct GPUShader *gpencil_fx_pixel_sh;
	struct GPUShader *gpencil_fx_rim_prepare_sh;
	struct GPUShader *gpencil_fx_rim_resolve_sh;
	struct GPUShader *gpencil_fx_shadow_prepare_sh;
	struct GPUShader *gpencil_fx_shadow_resolve_sh;
	struct GPUShader *gpencil_fx_swirl_sh;
	struct GPUShader *gpencil_fx_wave_sh;

	/* textures */
	struct GPUTexture *background_depth_tx;
	struct GPUTexture *background_color_tx;

	struct GPUTexture *gpencil_blank_texture;

	/* runtime pointers texture */
	struct GPUTexture *input_depth_tx;
	struct GPUTexture *input_color_tx;

	/* working textures */
	struct GPUTexture *temp_color_tx_a;
	struct GPUTexture *temp_depth_tx_a;

	struct GPUTexture *temp_color_tx_b;
	struct GPUTexture *temp_depth_tx_b;

	struct GPUTexture *temp_color_tx_fx;
	struct GPUTexture *temp_depth_tx_fx;

	/* for buffer only one batch is nedeed because the drawing is only of one stroke */
	GPUBatch *batch_buffer_stroke;
	GPUBatch *batch_buffer_fill;

	/* grid geometry */
	GPUBatch *batch_grid;

} GPENCIL_e_data; /* Engine data */

/* GPUBatch Cache */
typedef struct GpencilBatchCache {
	/* For normal strokes, a variable number of batch can be needed depending of number of strokes.
	   It could use the stroke number as total size, but when activate the onion skining, the number
	   can change, so the size is changed dynamically.
	 */
	GPUBatch **batch_stroke;
	GPUBatch **batch_fill;
	GPUBatch **batch_edit;
	GPUBatch **batch_edlin;

	/* settings to determine if cache is invalid */
	bool is_dirty;
	bool is_editmode;
	int cache_frame;

	/* keep information about the size of the cache */
	int cache_size;  /* total batch slots available */
	int cache_idx;   /* current slot index */
} GpencilBatchCache;

/* general drawing functions */
struct DRWShadingGroup *DRW_gpencil_shgroup_stroke_create(
        struct GPENCIL_e_data *e_data, struct GPENCIL_Data *vedata, struct DRWPass *pass, struct GPUShader *shader,
        struct Object *ob, struct bGPdata *gpd, struct MaterialGPencilStyle *gp_style, int id, bool onion);
void DRW_gpencil_populate_datablock(
        struct GPENCIL_e_data *e_data, void *vedata,
        struct Scene *scene,
        struct Object *ob, struct tGPencilObjectCache *cache_ob);
void DRW_gpencil_populate_buffer_strokes(
        struct GPENCIL_e_data *e_data, void *vedata, struct ToolSettings *ts, struct Object *ob);
void DRW_gpencil_populate_multiedit(
        struct GPENCIL_e_data *e_data, void *vedata,
        struct Scene *scene, struct Object *ob, struct tGPencilObjectCache *cache_ob);
void DRW_gpencil_triangulate_stroke_fill(struct Object *ob, struct bGPDstroke *gps);

void DRW_gpencil_multisample_ensure(struct GPENCIL_Data *vedata, int rect_w, int rect_h);

/* create geometry functions */
struct GPUBatch *DRW_gpencil_get_point_geom(struct bGPDstroke *gps, short thickness, const float ink[4]);
struct GPUBatch *DRW_gpencil_get_stroke_geom(struct bGPDstroke *gps, short thickness, const float ink[4]);
struct GPUBatch *DRW_gpencil_get_fill_geom(struct Object *ob, struct bGPDstroke *gps, const float color[4]);
struct GPUBatch *DRW_gpencil_get_edit_geom(struct bGPDstroke *gps, float alpha, short dflag);
struct GPUBatch *DRW_gpencil_get_edlin_geom(struct bGPDstroke *gps, float alpha, short dflag);
struct GPUBatch *DRW_gpencil_get_buffer_stroke_geom(struct bGPdata *gpd, short thickness);
struct GPUBatch *DRW_gpencil_get_buffer_fill_geom(struct bGPdata *gpd);
struct GPUBatch *DRW_gpencil_get_buffer_point_geom(struct bGPdata *gpd, short thickness);
struct GPUBatch *DRW_gpencil_get_grid(Object *ob);

/* object cache functions */
struct tGPencilObjectCache *gpencil_object_cache_add(
        struct tGPencilObjectCache *cache_array, struct Object *ob,
        int *gp_cache_size, int *gp_cache_used);

/* geometry batch cache functions */
void gpencil_batch_cache_check_free_slots(struct Object *ob);
struct GpencilBatchCache *gpencil_batch_cache_get(struct Object *ob, int cfra);

/* effects */
void GPENCIL_create_fx_shaders(struct GPENCIL_e_data *e_data);
void GPENCIL_delete_fx_shaders(struct GPENCIL_e_data *e_data);
void GPENCIL_create_fx_passes(struct GPENCIL_PassList *psl);

void DRW_gpencil_fx_prepare(
	struct GPENCIL_e_data *e_data, struct GPENCIL_Data *vedata,
	struct tGPencilObjectCache *cache);
void DRW_gpencil_fx_draw(
	struct GPENCIL_e_data *e_data, struct GPENCIL_Data *vedata,
	struct tGPencilObjectCache *cache);

/* main functions */
void GPENCIL_engine_init(void *vedata);
void GPENCIL_cache_init(void *vedata);
void GPENCIL_cache_populate(void *vedata, struct Object *ob);
void GPENCIL_cache_finish(void *vedata);
void GPENCIL_draw_scene(void *vedata);

/* render */
void GPENCIL_render_init(struct GPENCIL_Data *ved, struct RenderEngine *engine, struct Depsgraph *depsgraph);
void GPENCIL_render_to_image(void *vedata, struct RenderEngine *engine, struct RenderLayer *render_layer, const rcti *rect);

/* Use of multisample framebuffers. */
#define MULTISAMPLE_GP_SYNC_ENABLE(lvl, fbl) { \
	if ((lvl > 0) && (fbl->multisample_fb != NULL)) { \
		DRW_stats_query_start("GP Multisample Blit"); \
		GPU_framebuffer_bind(fbl->multisample_fb); \
		GPU_framebuffer_clear_color_depth(fbl->multisample_fb, (const float[4]){0.0f}, 1.0f); \
		DRW_stats_query_end(); \
	} \
}

#define MULTISAMPLE_GP_SYNC_DISABLE(lvl, fbl, fb, txl) { \
	if ((lvl > 0) && (fbl->multisample_fb != NULL)) { \
		DRW_stats_query_start("GP Multisample Resolve"); \
		GPU_framebuffer_bind(fb); \
		DRW_multisamples_resolve(txl->multisample_depth, txl->multisample_color, true); \
		DRW_stats_query_end(); \
	} \
}

#endif /* __GPENCIL_ENGINE_H__ */
