blender-archive/source/blender/draw/modes/particle_mode.c

/*
 * 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.
 *
 * Copyright 2016, Blender Foundation.
 */

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

#include "DRW_render.h"

#include "DNA_object_types.h"
#include "DNA_particle_types.h"

#include "BKE_pointcache.h"

#include "GPU_shader.h"

#include "draw_common.h"

#include "ED_particle.h"

#include "DEG_depsgraph_query.h"

extern char datatoc_particle_strand_vert_glsl[];
extern char datatoc_particle_strand_frag_glsl[];
extern char datatoc_common_globals_lib_glsl[];

/* *********** LISTS *********** */

typedef struct PARTICLE_PassList {
	struct DRWPass *psys_edit_pass;
} PARTICLE_PassList;

typedef struct PARTICLE_FramebufferList {
	struct GPUFrameBuffer *fb;
} PARTICLE_FramebufferList;

typedef struct PARTICLE_TextureList {
	struct GPUTexture *texture;
} PARTICLE_TextureList;

typedef struct PARTICLE_StorageList {
	struct CustomStruct *block;
	struct PARTICLE_PrivateData *g_data;
} PARTICLE_StorageList;

typedef struct PARTICLE_Data {
	void *engine_type; /* Required */
	PARTICLE_FramebufferList *fbl;
	PARTICLE_TextureList *txl;
	PARTICLE_PassList *psl;
	PARTICLE_StorageList *stl;
} PARTICLE_Data;

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

static struct {
	struct GPUShader *strands_shader;
	struct GPUShader *strands_weight_shader;
	struct GPUShader *points_shader;
} e_data = {NULL}; /* Engine data */

typedef struct PARTICLE_PrivateData {
	DRWShadingGroup *strands_group;
	DRWShadingGroup *inner_points_group;
	DRWShadingGroup *tip_points_group;
} PARTICLE_PrivateData; /* Transient data */

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

static void particle_engine_init(void *UNUSED(vedata))
{
	if (!e_data.strands_shader) {
		e_data.strands_shader = DRW_shader_create_with_lib(
		        datatoc_particle_strand_vert_glsl,
		        NULL,
		        datatoc_particle_strand_frag_glsl,
		        datatoc_common_globals_lib_glsl,
		        "");

		e_data.strands_weight_shader = DRW_shader_create_with_lib(
		        datatoc_particle_strand_vert_glsl,
		        NULL,
		        datatoc_particle_strand_frag_glsl,
		        datatoc_common_globals_lib_glsl,
		        "#define USE_WEIGHT");

		e_data.points_shader = DRW_shader_create_with_lib(
		        datatoc_particle_strand_vert_glsl,
		        NULL,
		        datatoc_particle_strand_frag_glsl,
		        datatoc_common_globals_lib_glsl,
		        "#define USE_POINTS");
	}
}

static void particle_cache_init(void *vedata)
{
	PARTICLE_PassList *psl = ((PARTICLE_Data *)vedata)->psl;
	PARTICLE_StorageList *stl = ((PARTICLE_Data *)vedata)->stl;
	const DRWContextState *draw_ctx = DRW_context_state_get();
	ParticleEditSettings *pset = PE_settings(draw_ctx->scene);
	const bool use_weight = (pset->brushtype == PE_BRUSH_WEIGHT);

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

	/* Create a pass */
	psl->psys_edit_pass = DRW_pass_create("PSys Edit Pass",
	                                      (DRW_STATE_WRITE_COLOR |
	                                       DRW_STATE_WRITE_DEPTH |
	                                       DRW_STATE_DEPTH_LESS_EQUAL |
	                                       DRW_STATE_WIRE |
	                                       DRW_STATE_POINT));

	GPUShader *strand_shader = (use_weight) ? e_data.strands_weight_shader : e_data.strands_shader;
	stl->g_data->strands_group = DRW_shgroup_create(strand_shader, psl->psys_edit_pass);
	stl->g_data->inner_points_group = DRW_shgroup_create(e_data.points_shader, psl->psys_edit_pass);
	stl->g_data->tip_points_group = DRW_shgroup_create(e_data.points_shader, psl->psys_edit_pass);

	DRW_shgroup_uniform_block(stl->g_data->strands_group, "globalsBlock", G_draw.block_ubo);
	DRW_shgroup_uniform_block(stl->g_data->inner_points_group, "globalsBlock", G_draw.block_ubo);
	DRW_shgroup_uniform_block(stl->g_data->tip_points_group, "globalsBlock", G_draw.block_ubo);
}

static void particle_edit_cache_populate(void *vedata,
                                         Object *object,
                                         ParticleSystem *psys,
                                         PTCacheEdit *edit)
{
	PARTICLE_StorageList *stl = ((PARTICLE_Data *)vedata)->stl;
	const DRWContextState *draw_ctx = DRW_context_state_get();
	ParticleEditSettings *pset = PE_settings(draw_ctx->scene);
	const bool use_weight = (pset->brushtype == PE_BRUSH_WEIGHT);
	{
		struct GPUBatch *strands =
		        DRW_cache_particles_get_edit_strands(object, psys, edit, use_weight);
		DRW_shgroup_call_add(stl->g_data->strands_group, strands, NULL);
	}
	if (pset->selectmode == SCE_SELECT_POINT) {
		struct GPUBatch *points =
		        DRW_cache_particles_get_edit_inner_points(object, psys, edit);
		DRW_shgroup_call_add(stl->g_data->inner_points_group, points, NULL);
	}
	if (ELEM(pset->selectmode, SCE_SELECT_POINT, SCE_SELECT_END)) {
		struct GPUBatch *points =
		        DRW_cache_particles_get_edit_tip_points(object, psys, edit);
		DRW_shgroup_call_add(stl->g_data->tip_points_group, points, NULL);
	}
}

static void particle_cache_populate(void *vedata, Object *object)
{
	if (object->mode != OB_MODE_PARTICLE_EDIT) {
		return;
	}
	const DRWContextState *draw_ctx = DRW_context_state_get();
	Scene *scene_orig = (Scene *)DEG_get_original_id(&draw_ctx->scene->id);
	/* Usually the edit structure is created by Particle Edit Mode Toggle
	 * operator, but sometimes it's invoked after tagging hair as outdated
	 * (for example, when toggling edit mode). That makes it impossible to
	 * create edit structure for until after next dependency graph evaluation.
	 *
	 * Ideally, the edit structure will be created here already via some
	 * dependency graph callback or so, but currently trying to make it nicer
	 * only causes bad level calls and breaks design from the past.
	 */
	Object *object_orig = DEG_get_original_object(object);
	PTCacheEdit *edit = PE_create_current(
	        draw_ctx->depsgraph, scene_orig, object_orig);
	if (edit == NULL) {
		/* Happens when trying to edit particles in EMITTER mode without
		 * having them cached.
		 */
		return;
	}
	/* NOTE: We need to pass evaluated particle system, which we need
	 * to find first.
	 */
	ParticleSystem *psys = object->particlesystem.first;
	ParticleSystem *psys_orig = object_orig->particlesystem.first;
	while (psys_orig != NULL) {
		if (PE_get_current_from_psys(psys_orig) == edit) {
			break;
		}
		psys = psys->next;
		psys_orig = psys_orig->next;
	}
	if (psys == NULL) {
		printf("Error getting evaluated particle system for edit.\n");
		return;
	}
	particle_edit_cache_populate(vedata, object, psys, edit);
}

/* Optional: Post-cache_populate callback */
static void particle_cache_finish(void *UNUSED(vedata))
{
}

/* Draw time ! Control rendering pipeline from here */
static void particle_draw_scene(void *vedata)
{

	PARTICLE_PassList *psl = ((PARTICLE_Data *)vedata)->psl;

	DRW_draw_pass(psl->psys_edit_pass);
}

static void particle_engine_free(void)
{
	DRW_SHADER_FREE_SAFE(e_data.strands_shader);
	DRW_SHADER_FREE_SAFE(e_data.strands_weight_shader);
	DRW_SHADER_FREE_SAFE(e_data.points_shader);
}

static const DrawEngineDataSize particle_data_size =
      DRW_VIEWPORT_DATA_SIZE(PARTICLE_Data);

DrawEngineType draw_engine_particle_type = {
	NULL, NULL,
	N_("Particle Mode"),
	&particle_data_size,
	&particle_engine_init,
	&particle_engine_free,
	&particle_cache_init,
	&particle_cache_populate,
	&particle_cache_finish,
	NULL, /* draw_background but not needed by mode engines */
	&particle_draw_scene,
	NULL,
	NULL,
};