/*
 * Copyright 2016, 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): Blender Institute
 *
 */

/** \file blender/draw/modes/edit_armature_mode.c
 *  \ingroup draw
 */

#include "DRW_engine.h"
#include "DRW_render.h"

#include "DNA_armature_types.h"
#include "DNA_view3d_types.h"

#include "draw_common.h"

#include "draw_mode_engines.h"

extern GlobalsUboStorage ts;

/* *********** LISTS *********** */
typedef struct EDIT_ARMATURE_PassList {
	struct DRWPass *bone_solid;
	struct DRWPass *bone_wire;
	struct DRWPass *bone_outline;
	struct DRWPass *bone_envelope;
	struct DRWPass *bone_axes;
	struct DRWPass *relationship;
} EDIT_ARMATURE_PassList;

typedef struct EDIT_ARMATURE_StorageList {
	struct EDIT_ARMATURE_PrivateData *g_data;
} EDIT_ARMATURE_StorageList;

typedef struct EDIT_ARMATURE_Data {
	void *engine_type;
	DRWViewportEmptyList *fbl;
	DRWViewportEmptyList *txl;
	EDIT_ARMATURE_PassList *psl;
	EDIT_ARMATURE_StorageList *stl;
} EDIT_ARMATURE_Data;

/* *********** STATIC *********** */

typedef struct EDIT_ARMATURE_PrivateData {
	char pad; /* UNUSED */
} EDIT_ARMATURE_PrivateData; /* Transient data */

/* *********** FUNCTIONS *********** */

static void EDIT_ARMATURE_cache_init(void *vedata)
{
	EDIT_ARMATURE_PassList *psl = ((EDIT_ARMATURE_Data *)vedata)->psl;
	EDIT_ARMATURE_StorageList *stl = ((EDIT_ARMATURE_Data *)vedata)->stl;

	if (!stl->g_data) {
		/* Alloc transient pointers */
		stl->g_data = MEM_mallocN(sizeof(*stl->g_data), __func__);
	}

	{
		/* Solid bones */
		DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS_EQUAL | DRW_STATE_CULL_BACK;
		psl->bone_solid = DRW_pass_create("Bone Solid Pass", state);
	}

	{
		/* Bones Outline */
		DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS_EQUAL;
		psl->bone_outline = DRW_pass_create("Bone Outline Pass", state);
	}

	{
		/* Wire bones */
		DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS_EQUAL | DRW_STATE_BLEND;
		psl->bone_wire = DRW_pass_create("Bone Wire Pass", state);
	}

	{
		/* distance outline around envelope bones */
		DRWState state = DRW_STATE_ADDITIVE | DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_LESS_EQUAL | DRW_STATE_CULL_FRONT;
		psl->bone_envelope = DRW_pass_create("Bone Envelope Outline Pass", state);
	}

	{
		DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WIRE_SMOOTH | DRW_STATE_BLEND;
		psl->bone_axes = DRW_pass_create("Bone Axes Pass", state);
	}

	{
		/* Non Meshes Pass (Camera, empties, lamps ...) */
		DRWState state =
		        DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS_EQUAL |
		        DRW_STATE_BLEND | DRW_STATE_WIRE;
		psl->relationship = DRW_pass_create("Bone Relationship Pass", state);
	}
}

static void EDIT_ARMATURE_cache_populate(void *vedata, Object *ob)
{
	bArmature *arm = ob->data;
	EDIT_ARMATURE_PassList *psl = ((EDIT_ARMATURE_Data *)vedata)->psl;

	if (ob->type == OB_ARMATURE) {
		if (arm->edbo) {
			DRWArmaturePasses passes = {
			    .bone_solid = psl->bone_solid,
			    .bone_outline = psl->bone_outline,
			    .bone_wire = psl->bone_wire,
			    .bone_envelope = psl->bone_envelope,
			    .bone_axes = psl->bone_axes,
			    .relationship_lines = psl->relationship,
			};
			DRW_shgroup_armature_edit(ob, passes);
		}
	}
}

static void EDIT_ARMATURE_draw_scene(void *vedata)
{
	EDIT_ARMATURE_PassList *psl = ((EDIT_ARMATURE_Data *)vedata)->psl;
	DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
	DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
	const DRWContextState *draw_ctx = DRW_context_state_get();
	const bool transparent_bones = (draw_ctx->v3d->overlay.arm_flag & V3D_OVERLAY_ARM_TRANSP_BONES) != 0;

	DRW_draw_pass(psl->bone_envelope);

	if (transparent_bones) {
		DRW_pass_state_add(psl->bone_solid, DRW_STATE_BLEND);
		DRW_pass_state_remove(psl->bone_solid, DRW_STATE_WRITE_DEPTH);
		DRW_draw_pass(psl->bone_solid);
	}

	MULTISAMPLE_SYNC_ENABLE(dfbl, dtxl)

	if (!transparent_bones) {
		DRW_draw_pass(psl->bone_solid);
	}

	DRW_draw_pass(psl->bone_outline);
	DRW_draw_pass(psl->bone_wire);
	DRW_draw_pass(psl->relationship);

	MULTISAMPLE_SYNC_DISABLE(dfbl, dtxl)

	/* Draw axes with linesmooth and outside of multisample buffer. */
	DRW_draw_pass(psl->bone_axes);
}

static const DrawEngineDataSize EDIT_ARMATURE_data_size = DRW_VIEWPORT_DATA_SIZE(EDIT_ARMATURE_Data);

DrawEngineType draw_engine_edit_armature_type = {
	NULL, NULL,
	N_("EditArmatureMode"),
	&EDIT_ARMATURE_data_size,
	NULL,
	NULL,
	&EDIT_ARMATURE_cache_init,
	&EDIT_ARMATURE_cache_populate,
	NULL,
	NULL,
	&EDIT_ARMATURE_draw_scene,
	NULL,
	NULL,
};