path: root/source/blender/draw/engines/eevee/eevee_depth_of_field.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
 * \ingroup draw_engine
 *
 * Depth of field post process effect.
 */

#include "DRW_render.h"

#include "DNA_camera_types.h"
#include "DNA_screen_types.h"
#include "DNA_view3d_types.h"
#include "DNA_world_types.h"

#include "BKE_camera.h"

#include "BLI_string_utils.h"

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

#include "GPU_framebuffer.h"
#include "GPU_texture.h"
#include "eevee_private.h"

static struct {
  /* Depth Of Field */
  struct GPUShader *dof_downsample_sh[2];
  struct GPUShader *dof_scatter_sh[2];
  struct GPUShader *dof_resolve_sh[2];
} e_data = {{NULL}}; /* Engine data */

extern char datatoc_effect_dof_vert_glsl[];
extern char datatoc_effect_dof_frag_glsl[];

extern char datatoc_common_view_lib_glsl[];

static void eevee_create_shader_depth_of_field(const bool use_alpha)
{
  char *frag = BLI_string_joinN(datatoc_common_view_lib_glsl, datatoc_effect_dof_frag_glsl);
  e_data.dof_downsample_sh[use_alpha] = DRW_shader_create_fullscreen(
      frag,
      use_alpha ? "#define USE_ALPHA_DOF\n"
                  "#define STEP_DOWNSAMPLE\n" :
                  "#define STEP_DOWNSAMPLE\n");
  e_data.dof_scatter_sh[use_alpha] = DRW_shader_create(datatoc_effect_dof_vert_glsl,
                                                       NULL,
                                                       frag,
                                                       use_alpha ? "#define USE_ALPHA_DOF\n"
                                                                   "#define STEP_SCATTER\n" :
                                                                   "#define STEP_SCATTER\n");
  e_data.dof_resolve_sh[use_alpha] = DRW_shader_create_fullscreen(frag,
                                                                  use_alpha ?
                                                                      "#define USE_ALPHA_DOF\n"
                                                                      "#define STEP_RESOLVE\n" :
                                                                      "#define STEP_RESOLVE\n");
  MEM_freeN(frag);
}

int EEVEE_depth_of_field_init(EEVEE_ViewLayerData *UNUSED(sldata),
                              EEVEE_Data *vedata,
                              Object *camera)
{
  EEVEE_StorageList *stl = vedata->stl;
  EEVEE_FramebufferList *fbl = vedata->fbl;
  EEVEE_EffectsInfo *effects = stl->effects;

  const DRWContextState *draw_ctx = DRW_context_state_get();
  const Scene *scene_eval = DEG_get_evaluated_scene(draw_ctx->depsgraph);

  Camera *cam = (camera != NULL) ? camera->data : NULL;

  if (cam && (cam->dof.flag & CAM_DOF_ENABLED)) {
    RegionView3D *rv3d = draw_ctx->rv3d;
    const bool use_alpha = !DRW_state_draw_background();

    if (!e_data.dof_downsample_sh[use_alpha]) {
      eevee_create_shader_depth_of_field(use_alpha);
    }

    const float *viewport_size = DRW_viewport_size_get();

    /* Retrieve Near and Far distance */
    effects->dof_near_far[0] = -cam->clip_start;
    effects->dof_near_far[1] = -cam->clip_end;

    int buffer_size[2] = {(int)viewport_size[0] / 2, (int)viewport_size[1] / 2};

    buffer_size[0] = max_ii(1, buffer_size[0]);
    buffer_size[1] = max_ii(1, buffer_size[1]);

    eGPUTextureFormat down_format = DRW_state_draw_background() ? GPU_R11F_G11F_B10F : GPU_RGBA16F;

    effects->dof_down_near = DRW_texture_pool_query_2d(
        buffer_size[0], buffer_size[1], down_format, &draw_engine_eevee_type);
    effects->dof_down_far = DRW_texture_pool_query_2d(
        buffer_size[0], buffer_size[1], down_format, &draw_engine_eevee_type);
    effects->dof_coc = DRW_texture_pool_query_2d(
        buffer_size[0], buffer_size[1], GPU_RG16F, &draw_engine_eevee_type);

    GPU_framebuffer_ensure_config(&fbl->dof_down_fb,
                                  {GPU_ATTACHMENT_NONE,
                                   GPU_ATTACHMENT_TEXTURE(effects->dof_down_near),
                                   GPU_ATTACHMENT_TEXTURE(effects->dof_down_far),
                                   GPU_ATTACHMENT_TEXTURE(effects->dof_coc)});

    /* Go full 32bits for rendering and reduce the color artifacts. */
    eGPUTextureFormat fb_format = DRW_state_is_image_render() ? GPU_RGBA32F : GPU_RGBA16F;

    effects->dof_blur = DRW_texture_pool_query_2d(
        buffer_size[0] * 2, buffer_size[1], fb_format, &draw_engine_eevee_type);

    GPU_framebuffer_ensure_config(&fbl->dof_scatter_fb,
                                  {
                                      GPU_ATTACHMENT_NONE,
                                      GPU_ATTACHMENT_TEXTURE(effects->dof_blur),
                                  });

    if (!DRW_state_draw_background()) {
      effects->dof_blur_alpha = DRW_texture_pool_query_2d(
          buffer_size[0] * 2, buffer_size[1], GPU_R32F, &draw_engine_eevee_type);
      GPU_framebuffer_texture_attach(fbl->dof_scatter_fb, effects->dof_blur_alpha, 1, 0);
    }

    /* Parameters */
    /* TODO UI Options */
    float fstop = cam->dof.aperture_fstop;
    float blades = cam->dof.aperture_blades;
    float rotation = cam->dof.aperture_rotation;
    float ratio = 1.0f / cam->dof.aperture_ratio;
    float sensor = BKE_camera_sensor_size(cam->sensor_fit, cam->sensor_x, cam->sensor_y);
    float focus_dist = BKE_camera_object_dof_distance(camera);
    float focal_len = cam->lens;

    const float scale_camera = 0.001f;
    /* we want radius here for the aperture number  */
    float aperture = 0.5f * scale_camera * focal_len / fstop;
    float focal_len_scaled = scale_camera * focal_len;
    float sensor_scaled = scale_camera * sensor;

    if (rv3d != NULL) {
      sensor_scaled *= rv3d->viewcamtexcofac[0];
    }

    effects->dof_params[1] = aperture * fabsf(focal_len_scaled / (focus_dist - focal_len_scaled));
    effects->dof_params[1] *= viewport_size[0] / sensor_scaled;
    effects->dof_params[0] = -focus_dist * effects->dof_params[1];

    effects->dof_bokeh[0] = rotation;
    effects->dof_bokeh[1] = ratio;
    effects->dof_bokeh[2] = scene_eval->eevee.bokeh_max_size;

    /* Precompute values to save instructions in fragment shader. */
    effects->dof_bokeh_sides[0] = blades;
    effects->dof_bokeh_sides[1] = blades > 0.0f ? 2.0f * M_PI / blades : 0.0f;
    effects->dof_bokeh_sides[2] = blades / (2.0f * M_PI);
    effects->dof_bokeh_sides[3] = blades > 0.0f ? cosf(M_PI / blades) : 0.0f;

    return EFFECT_DOF | EFFECT_POST_BUFFER;
  }

  /* Cleanup to release memory */
  GPU_FRAMEBUFFER_FREE_SAFE(fbl->dof_down_fb);
  GPU_FRAMEBUFFER_FREE_SAFE(fbl->dof_scatter_fb);

  return 0;
}

void EEVEE_depth_of_field_cache_init(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *vedata)
{
  EEVEE_PassList *psl = vedata->psl;
  EEVEE_StorageList *stl = vedata->stl;
  EEVEE_EffectsInfo *effects = stl->effects;
  DefaultTextureList *dtxl = DRW_viewport_texture_list_get();

  if ((effects->enabled_effects & EFFECT_DOF) != 0) {
    /**  Depth of Field algorithm
     *
     * Overview :
     * - Down-sample the color buffer into 2 buffers weighted with
     *   CoC values. Also output CoC into a texture.
     * - Shoot quads for every pixel and expand it depending on the CoC.
     *   Do one pass for near Dof and one pass for far Dof.
     * - Finally composite the 2 blurred buffers with the original render.
     */
    DRWShadingGroup *grp;
    struct GPUBatch *quad = DRW_cache_fullscreen_quad_get();
    const bool use_alpha = !DRW_state_draw_background();

    DRW_PASS_CREATE(psl->dof_down, DRW_STATE_WRITE_COLOR);

    grp = DRW_shgroup_create(e_data.dof_downsample_sh[use_alpha], psl->dof_down);
    DRW_shgroup_uniform_texture_ref(grp, "colorBuffer", &effects->source_buffer);
    DRW_shgroup_uniform_texture_ref(grp, "depthBuffer", &dtxl->depth);
    DRW_shgroup_uniform_vec2(grp, "nearFar", effects->dof_near_far, 1);
    DRW_shgroup_uniform_vec2(grp, "dofParams", effects->dof_params, 1);
    DRW_shgroup_call(grp, quad, NULL);

    DRW_PASS_CREATE(psl->dof_scatter, DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_ADD_FULL);

    /* This create an empty batch of N triangles to be positioned
     * by the vertex shader 0.4ms against 6ms with instancing */
    const float *viewport_size = DRW_viewport_size_get();
    const int sprite_len = ((int)viewport_size[0] / 2) *
                           ((int)viewport_size[1] / 2); /* brackets matters */
    grp = DRW_shgroup_create(e_data.dof_scatter_sh[use_alpha], psl->dof_scatter);
    DRW_shgroup_uniform_texture_ref(grp, "nearBuffer", &effects->dof_down_near);
    DRW_shgroup_uniform_texture_ref(grp, "farBuffer", &effects->dof_down_far);
    DRW_shgroup_uniform_texture_ref(grp, "cocBuffer", &effects->dof_coc);
    DRW_shgroup_uniform_vec4(grp, "bokehParams", effects->dof_bokeh, 2);

    DRW_shgroup_call_procedural_triangles(grp, NULL, sprite_len);

    DRW_PASS_CREATE(psl->dof_resolve, DRW_STATE_WRITE_COLOR);

    grp = DRW_shgroup_create(e_data.dof_resolve_sh[use_alpha], psl->dof_resolve);
    DRW_shgroup_uniform_texture_ref(grp, "scatterBuffer", &effects->dof_blur);
    DRW_shgroup_uniform_texture_ref(grp, "colorBuffer", &effects->source_buffer);
    DRW_shgroup_uniform_texture_ref(grp, "depthBuffer", &dtxl->depth);
    DRW_shgroup_uniform_vec2(grp, "nearFar", effects->dof_near_far, 1);
    DRW_shgroup_uniform_vec2(grp, "dofParams", effects->dof_params, 1);
    DRW_shgroup_call(grp, quad, NULL);

    if (use_alpha) {
      DRW_shgroup_uniform_texture_ref(grp, "scatterAlphaBuffer", &effects->dof_blur_alpha);
      DRW_shgroup_uniform_bool_copy(grp, "unpremult", DRW_state_is_image_render());
    }
  }
}

void EEVEE_depth_of_field_draw(EEVEE_Data *vedata)
{
  EEVEE_PassList *psl = vedata->psl;
  EEVEE_TextureList *txl = vedata->txl;
  EEVEE_FramebufferList *fbl = vedata->fbl;
  EEVEE_StorageList *stl = vedata->stl;
  EEVEE_EffectsInfo *effects = stl->effects;

  /* Depth Of Field */
  if ((effects->enabled_effects & EFFECT_DOF) != 0) {
    float clear_col[4] = {0.0f, 0.0f, 0.0f, 0.0f};

    /* Downsample */
    GPU_framebuffer_bind(fbl->dof_down_fb);
    DRW_draw_pass(psl->dof_down);

    /* Scatter */
    GPU_framebuffer_bind(fbl->dof_scatter_fb);
    GPU_framebuffer_clear_color(fbl->dof_scatter_fb, clear_col);
    DRW_draw_pass(psl->dof_scatter);

    /* Resolve */
    GPU_framebuffer_bind(effects->target_buffer);
    DRW_draw_pass(psl->dof_resolve);
    SWAP_BUFFERS();
  }
}

void EEVEE_depth_of_field_free(void)
{
  for (int i = 0; i < 2; i++) {
    DRW_SHADER_FREE_SAFE(e_data.dof_downsample_sh[i]);
    DRW_SHADER_FREE_SAFE(e_data.dof_scatter_sh[i]);
    DRW_SHADER_FREE_SAFE(e_data.dof_resolve_sh[i]);
  }
}