Differential D2889 Diff 11288 source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c

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source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c

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				/*
				* *** BEGIN GPL LICENSE BLOCK ***
				*
				* 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.
				*
				* The Original Code is Copyright (C) 2017, Blender Foundation
				* This is a new part of Blender
				*
				* Contributor(s): Antonio Vazquez, Joshua Leung
				*
				* *** END GPL LICENSE BLOCK ***
				*
				*/

				/** \file blender/modifiers/intern/MOD_gpencilbuild.c
				* \ingroup modifiers
				*/

				#include <stdio.h>

				#include "MEM_guardedalloc.h"

				#include "DNA_meshdata_types.h"
				#include "DNA_scene_types.h"
				#include "DNA_object_types.h"
				#include "DNA_gpencil_types.h"
				#include "DNA_gpencil_modifier_types.h"

				#include "BLI_blenlib.h"
				#include "BLI_math.h"
				#include "BLI_utildefines.h"

				#include "BKE_context.h"
				#include "BKE_gpencil.h"
				#include "BKE_gpencil_modifier.h"

				#include "DEG_depsgraph.h"
				#include "DEG_depsgraph_query.h"

				#include "MOD_gpencil_util.h"
				#include "MOD_gpencil_modifiertypes.h"

				static void initData(GpencilModifierData *md)
				{
				BuildGpencilModifierData gpmd = (BuildGpencilModifierData )md;

				/* We deliberately set this range to the half the default
				* frame-range to have an immediate effect ot suggest use-cases
				*/
				gpmd->start_frame = 1;
				gpmd->end_frame = 125;

				/* Init default length of each build effect - Nothing special */
				gpmd->start_delay = 0.0f;
				gpmd->length = 100.0f;
				}

				static void copyData(const GpencilModifierData md, GpencilModifierData target)
				{
				BKE_gpencil_modifier_copyData_generic(md, target);
				}

				static bool dependsOnTime(GpencilModifierData *UNUSED(md))
				{
				return true;
				}

				/* ******************************************** */
				/* Build Modifier - Stroke generation logic
				*
				* There are two modes for how the strokes are sequenced (at a macro-level):
				* - Sequential Mode - Strokes appear/disappear one after the other. Only a single one changes at a time.
				* - Concurrent Mode - Multiple strokes appear/disappear at once.
				*
				* Assumptions:
				* - Stroke points are generally equally spaced. This implies that we can just add/remove points,
				* without worrying about distances between them / adding extra interpolated points between
				* an visible point and one about to be added/removed (or any similar tapering effects).

				* - All strokes present are fully visible (i.e. we don't have to ignore any)
				*/

				/* Remove a particular stroke */
				static void clear_stroke(bGPDframe gpf, bGPDstroke gps)
				{
				BLI_remlink(&gpf->strokes, gps);
				BKE_gpencil_free_stroke(gps);
				}

				/* Clear all strokes in frame */
				static void gpf_clear_all_strokes(bGPDframe *gpf)
				{
				bGPDstroke gps, gps_next;
				for (gps = gpf->strokes.first; gps; gps = gps_next) {
				gps_next = gps->next;
				clear_stroke(gpf, gps);
				}
				BLI_listbase_clear(&gpf->strokes);
				}

				/* Reduce the number of points in the stroke
				*
				* Note: This won't be called if all points are present/removed
				* TODO: Allow blending of growing/shrinking tip (e.g. for more gradual transitions)
				*/
				static void reduce_stroke_points(bGPDstroke *gps, const int num_points, const eBuildGpencil_Transition transition)
				{
				bGPDspoint new_points = MEM_callocN(sizeof(bGPDspoint) num_points, "GP Build Modifier - Reduced Points");
				MDeformVert new_dvert = MEM_callocN(sizeof(MDeformVert) num_points, "GP Build Modifier - Reduced Weights");

				/* Which end should points be removed from */
				// TODO: free stroke weights
				switch (transition) {
				case GP_BUILD_TRANSITION_GROW: /* Show in forward order = Remove ungrown-points from end of stroke */
				case GP_BUILD_TRANSITION_SHRINK: /* Hide in reverse order = Remove dead-points from end of stroke */
				{
				/* copy over point data */
				memcpy(new_points, gps->points, sizeof(bGPDspoint) * num_points);
				memcpy(new_dvert, gps->dvert, sizeof(MDeformVert) * num_points);

				/* free unused point weights */
				for (int i = num_points; i < gps->totpoints; i++) {
				MDeformVert *dvert = &gps->dvert[i];
				BKE_gpencil_free_point_weights(dvert);
				}

				break;
				}

				/* Hide in forward order = Remove points from start of stroke */
				case GP_BUILD_TRANSITION_FADE:
				{
				/* num_points is the number of points left after reducing.
				* We need to know how many to remove
				*/
				const int offset = gps->totpoints - num_points;

				/* copy over point data */
				memcpy(new_points, gps->points + offset, sizeof(bGPDspoint) * num_points);
				memcpy(new_dvert, gps->dvert + offset, sizeof(MDeformVert) * num_points);

				/* free unused weights */
				for (int i = 0; i < offset; i++) {
				MDeformVert *dvert = &gps->dvert[i];
				BKE_gpencil_free_point_weights(dvert);
				}

				break;
				}

				default:
				printf("ERROR: Unknown transition %d in %s()\n", (int)transition, __func__);
				break;
				}

				/* replace stroke geometry */
				MEM_SAFE_FREE(gps->points);
				MEM_SAFE_FREE(gps->dvert);
				gps->points = new_points;
				gps->dvert = new_dvert;
				gps->totpoints = num_points;

				/* mark stroke as needing to have its geometry caches rebuilt */
				gps->flag \|= GP_STROKE_RECALC_CACHES;
				gps->tot_triangles = 0;
				MEM_SAFE_FREE(gps->triangles);
				}

				/* --------------------------------------------- */

				/* Stroke Data Table Entry - This represents one stroke being generated */
				typedef struct tStrokeBuildDetails {
				bGPDstroke *gps;

				/* Indices - first/last indices for the stroke's points (overall) */
				size_t start_idx, end_idx;

				/* Number of points - Cache for more convenient access */
				int totpoints;
				} tStrokeBuildDetails;


				/* Sequential - Show strokes one after the other */
				static void build_sequential(BuildGpencilModifierData mmd, bGPDframe gpf, float fac)
				{
				const size_t tot_strokes = BLI_listbase_count(&gpf->strokes);
				bGPDstroke *gps;
				size_t i;

				/* 1) Compute proportion of time each stroke should occupy */
				/* NOTE: This assumes that the total number of points won't overflow! */
				tStrokeBuildDetails table = MEM_callocN(sizeof(tStrokeBuildDetails) tot_strokes, "tStrokeBuildDetails");
				size_t totpoints = 0;

				/* 1.1) First pass - Tally up points */
				for (gps = gpf->strokes.first, i = 0; gps; gps = gps->next, i++) {
				tStrokeBuildDetails *cell = &table[i];

				cell->gps = gps;
				cell->totpoints = gps->totpoints;

				totpoints += cell->totpoints;
				}

				/* 1.2) Second pass - Compute the overall indices for points */
				for (i = 0; i < tot_strokes; i++) {
				tStrokeBuildDetails *cell = &table[i];

				if (i == 0) {
				cell->start_idx = 0;
				}
				else {
				cell->start_idx = (cell - 1)->end_idx;
				}
				cell->end_idx = cell->start_idx + cell->totpoints - 1;
				}


				/* 2) Determine the global indices for points that should be visible */
				size_t first_visible = 0;
				size_t last_visible = 0;

				switch (mmd->transition) {
				/* Show in forward order
				* - As fac increases, the number of visible points increases
				*/
				case GP_BUILD_TRANSITION_GROW:
				first_visible = 0; /* always visible */
				last_visible = (size_t)roundf(totpoints * fac);
				break;

				/* Hide in reverse order
				* - As fac increases, the number of points visible at the end decreases
				*/
				case GP_BUILD_TRANSITION_SHRINK:
				first_visible = 0; /* always visible (until last point removed) */
				last_visible = (size_t)(totpoints * (1.0f - fac));
				break;

				/* Hide in forward order
				* - As fac increases, the early points start getting hidden
				*/
				case GP_BUILD_TRANSITION_FADE:
				first_visible = (size_t)(totpoints * fac);
				last_visible = totpoints; /* i.e. visible until the end, unless first overlaps this */
				break;
				}


				/* 3) Go through all strokes, deciding which to keep, and/or how much of each to keep */
				for (i = 0; i < tot_strokes; i++) {
				tStrokeBuildDetails *cell = &table[i];

				/* Determine what portion of the stroke is visible */
				if ((cell->end_idx < first_visible) \|\| (cell->start_idx > last_visible)) {
				/* Not visible at all - Either ended before */
				clear_stroke(gpf, cell->gps);
				}
				else {
				/* Some proportion of stroke is visible */
				/* XXX: Will the transition settings still be valid now? */
				if ((first_visible <= cell->start_idx) && (last_visible >= cell->end_idx)) {
				/* Do nothing - whole stroke is visible */
				}
				else if (first_visible > cell->start_idx) {
				/* Starts partway through this stroke */
				int num_points = cell->end_idx - first_visible;
				reduce_stroke_points(cell->gps, num_points, mmd->transition);
				}
				else {
				/* Ends partway through this stroke */
				int num_points = last_visible - cell->start_idx;
				reduce_stroke_points(cell->gps, num_points, mmd->transition);
				}
				}
				}

				/* Free table */
				MEM_freeN(table);
				}

				/* --------------------------------------------- */

				/* Concurrent - Show multiple strokes at once */
				// TODO: Allow random offsets to start times
				// TODO: Allow varying speeds? Scaling of progress?
				static void build_concurrent(BuildGpencilModifierData mmd, bGPDframe gpf, float fac)
				{
				bGPDstroke gps, gps_next;
				int max_points = 0;

				const bool reverse = (mmd->transition != GP_BUILD_TRANSITION_GROW);

				/* 1) Determine the longest stroke, to figure out when short strokes should start */
				/* FIXME: A really long stroke here could dwarf everything else, causing bad timings */
				for (gps = gpf->strokes.first; gps; gps = gps->next) {
				if (gps->totpoints > max_points) {
				max_points = gps->totpoints;
				}
				}
				if (max_points == 0) {
				printf("ERROR: Strokes are all empty (GP Build Modifier: %s)\n", __func__);
				return;
				}

				/* 2) For each stroke, determine how it should be handled */
				for (gps = gpf->strokes.first; gps; gps = gps_next) {
				gps_next = gps->next;

				/* Relative Length of Stroke - Relative to the longest stroke,
				* what proportion of the available time should this stroke use
				*/
				const float relative_len = (float)gps->totpoints / (float)max_points;

				/* Determine how many points should be left in the stroke */
				int num_points = 0;

				switch (mmd->time_alignment) {
				case GP_BUILD_TIMEALIGN_START: /* all start on frame 1 */
				{
				/* Build effect occurs over when fac = 0, to fac = relative_len */
				if (fac <= relative_len) {
				/* Scale fac to fit relative_len */
				/* FIXME: prevent potential div by zero (e.g. very short stroke vs one very long one) */
				const float scaled_fac = fac / relative_len;

				if (reverse) {
				num_points = (int)roundf((1.0f - scaled_fac) * gps->totpoints);
				}
				else {
				num_points = (int)roundf(scaled_fac * gps->totpoints);
				}
				}
				else {
				/* Build effect has ended */
				if (reverse) {
				num_points = 0;
				}
				else {
				num_points = gps->totpoints;
				}
				}

				break;
				}
				case GP_BUILD_TIMEALIGN_END: /* all end on same frame */
				{
				/* Build effect occurs over 1.0 - relative_len, to 1.0 (i.e. over the end of the range) */
				const float start_fac = 1.0f - relative_len;

				if (fac >= start_fac) {
				/* FIXME: prevent potential div by zero (e.g. very short stroke vs one very long one) */
				const float scaled_fac = (fac - start_fac) / relative_len;

				if (reverse) {
				num_points = (int)roundf((1.0f - scaled_fac) * gps->totpoints);
				}
				else {
				num_points = (int)roundf(scaled_fac * gps->totpoints);
				}
				}
				else {
				/* Build effect hasn't started */
				if (reverse) {
				num_points = gps->totpoints;
				}
				else {
				num_points = 0;
				}
				}

				break;
				}

				/* TODO... */
				}

				/* Modify the stroke geometry */
				if (num_points <= 0) {
				/* Nothing Left - Delete the stroke */
				clear_stroke(gpf, gps);
				}
				else if (num_points < gps->totpoints) {
				/* Remove some points */
				reduce_stroke_points(gps, num_points, mmd->transition);
				}
				}
				}

				/* --------------------------------------------- */

				/* Entry-point for Build Modifier */
				static void generateStrokes(
				GpencilModifierData md, Depsgraph depsgraph,
				Object UNUSED(ob), bGPDlayer gpl, bGPDframe *gpf)
				{
				BuildGpencilModifierData mmd = (BuildGpencilModifierData )md;
				const bool reverse = (mmd->transition != GP_BUILD_TRANSITION_GROW);

				const float ctime = DEG_get_ctime(depsgraph);
				//printf("GP Build Modifier - %f\n", ctime);

				/* Early exit if it's an empty frame */
				if (gpf->strokes.first == NULL) {
				return;
				}

				/* Omit layer if filter by layer */
				if (mmd->layername[0] != '\0') {
				if ((mmd->flag & GP_BUILD_INVERT_LAYER) == 0) {
				if (!STREQ(mmd->layername, gpl->info)) {
				return;
				}
				}
				else {
				if (STREQ(mmd->layername, gpl->info)) {
				return;
				}
				}
				}

				/* Early exit if outside of the frame range for this modifier
				* (e.g. to have one forward, and one backwards modifier)
				*/
				if (mmd->flag & GP_BUILD_RESTRICT_TIME) {
				if ((ctime < mmd->start_frame) \|\| (ctime > mmd->end_frame)) {
				return;
				}
				}

				/* Compute start and end frames for the animation effect
				* By default, the upper bound is given by the "maximum length" setting
				*/
				float start_frame = gpf->framenum + mmd->start_delay;
				float end_frame = gpf->framenum + mmd->length;

				if (gpf->next) {
				/* Use the next frame or upper bound as end frame, whichever is lower/closer */
				end_frame = MIN2(end_frame, gpf->next->framenum);
				}


				/* Early exit if current frame is outside start/end bounds */
				/* NOTE: If we're beyond the next/prev frames (if existent), then we wouldn't have this problem anyway... */
				if (ctime < start_frame) {
				/* Before Start - Animation hasn't started. Display initial state. */
				if (reverse) {
				/* 1) Reverse = Start with all, end with nothing.
				* ==> Do nothing (everything already present)
				*/
				}
				else {
				/* 2) Forward Order = Start with nothing, end with the full frame.
				* ==> Free all strokes, and return an empty frame
				*/
				gpf_clear_all_strokes(gpf);
				}

				/* Early exit */
				return;
				}
				else if (ctime >= end_frame) {
				/* Past End - Animation finished. Display final result. */
				if (reverse) {
				/* 1) Reverse = Start with all, end with nothing.
				* ==> Free all strokes, and return an empty frame
				*/
				gpf_clear_all_strokes(gpf);
				}
				else {
				/* 2) Forward Order = Start with nothing, end with the full frame.
				* ==> Do Nothing (everything already present)
				*/
				}

				/* Early exit */
				return;
				}


				/* Determine how far along we are between the keyframes */
				float fac = (ctime - start_frame) / (end_frame - start_frame);
				//printf(" Progress on %d = %f (%f - %f)\n", gpf->framenum, fac, start_frame, end_frame);

				/* Time management mode */
				switch (mmd->mode) {
				case GP_BUILD_MODE_SEQUENTIAL:
				build_sequential(mmd, gpf, fac);
				break;

				case GP_BUILD_MODE_CONCURRENT:
				build_concurrent(mmd, gpf, fac);
				break;

				default:
				printf("Unsupported build mode (%d) for GP Build Modifier: '%s'\n", mmd->mode, mmd->modifier.name);
				break;
				}
				}

				/* ******************************************** */

				/* FIXME: Baking the Build Modifier is currently unsupported.
				* Adding support for this is more complicated than for other
				* modifiers, as to implement this, we'd have to add more frames,
				* which would in turn break how the modifier functions.
				*/
				#if 0
				static void bakeModifier(
				Main bmain, const Depsgraph UNUSED(depsgraph),
				GpencilModifierData md, Object ob)
				{
				bGPdata *gpd = ob->data;

				for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
				for (bGPDframe *gpf = gpl->frames.first; gpf; gpf = gpf->next) {

				}
				}
				}
				#endif

				/* ******************************************** */

				GpencilModifierTypeInfo modifierType_Gpencil_Build = {
				/* name */ "Build",
				/* structName */ "BuildGpencilModifierData",
				/* structSize */ sizeof(BuildGpencilModifierData),
				/* type */ eGpencilModifierTypeType_Gpencil,
				/* flags */ 0,

				/* copyData */ copyData,

				/* deformStroke */ NULL,
				/* generateStrokes */ generateStrokes,
				/* bakeModifier */ NULL,

				/* initData */ initData,
				/* freeData */ NULL,
				/* isDisabled */ NULL,
				/* updateDepsgraph */ NULL,
				/* dependsOnTime */ dependsOnTime,
				/* foreachObjectLink */ NULL,
				/* foreachIDLink */ NULL,
				/* foreachTexLink */ NULL,
				};