EEVEE: GLSL Renderpasses

Most of the renderpasses in EEVEE used post-processing on the CPU. For
final image rendering this is sufficient, but when we want to display
the data to the user we don't want to transfer to the CPU to do post
processing to then upload it back to the GPU to display the result.

This patch moves the renderpass postprocessing to a GLSL shader.

This is the first step to do, before we will enable the renderpasses in the viewport.

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D6206

1 files changed, 61 insertions, 192 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_render.c b/source/blender/draw/engines/eevee/eevee_render.c
index ee1dc8a0208..9a7d170c9ea 100644
--- a/source/blender/draw/engines/eevee/eevee_render.c
+++ b/source/blender/draw/engines/eevee/eevee_render.c
@@ -130,7 +130,9 @@ void EEVEE_render_init(EEVEE_Data *ved, RenderEngine *engine, struct Depsgraph *
   DRW_view_default_set(view);
   DRW_view_set_active(view);
 
-  /* EEVEE_effects_init needs to go first for TAA */
+  /* `EEVEE_renderpasses_init` will set the active render passes used by `EEVEE_effects_init`.
+   * `EEVEE_effects_init` needs to go second for TAA. */
+  EEVEE_renderpasses_init(vedata);
   EEVEE_effects_init(sldata, vedata, ob_camera_eval, false);
   EEVEE_materials_init(sldata, stl, fbl);
   EEVEE_shadows_init(sldata);
@@ -202,79 +204,60 @@ void EEVEE_render_cache(void *vedata,
   }
 }
 
-static void eevee_render_result_combined(RenderLayer *rl,
-                                         const char *viewname,
-                                         const rcti *rect,
-                                         EEVEE_Data *vedata,
-                                         EEVEE_ViewLayerData *UNUSED(sldata))
+static void eevee_render_color_result(RenderLayer *rl,
+                                      const char *viewname,
+                                      const rcti *rect,
+                                      const char *render_pass_name,
+                                      int num_channels,
+                                      GPUFrameBuffer *framebuffer,
+                                      EEVEE_Data *vedata)
 {
-  RenderPass *rp = RE_pass_find_by_name(rl, RE_PASSNAME_COMBINED, viewname);
-
-  GPU_framebuffer_bind(vedata->stl->effects->final_fb);
-  GPU_framebuffer_read_color(vedata->stl->effects->final_fb,
+  RenderPass *rp = RE_pass_find_by_name(rl, render_pass_name, viewname);
+  GPU_framebuffer_bind(framebuffer);
+  GPU_framebuffer_read_color(framebuffer,
                              vedata->stl->g_data->overscan_pixels + rect->xmin,
                              vedata->stl->g_data->overscan_pixels + rect->ymin,
                              BLI_rcti_size_x(rect),
                              BLI_rcti_size_y(rect),
-                             4,
+                             num_channels,
                              0,
                              rp->rect);
 }
 
+static void eevee_render_result_combined(RenderLayer *rl,
+                                         const char *viewname,
+                                         const rcti *rect,
+                                         EEVEE_Data *vedata,
+                                         EEVEE_ViewLayerData *UNUSED(sldata))
+{
+  eevee_render_color_result(
+      rl, viewname, rect, RE_PASSNAME_COMBINED, 4, vedata->stl->effects->final_fb, vedata);
+}
+
 static void eevee_render_result_subsurface(RenderLayer *rl,
                                            const char *viewname,
                                            const rcti *rect,
                                            EEVEE_Data *vedata,
-                                           EEVEE_ViewLayerData *UNUSED(sldata),
-                                           int render_samples)
+                                           EEVEE_ViewLayerData *sldata)
 {
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  ViewLayer *view_layer = draw_ctx->view_layer;
-
   if (vedata->fbl->sss_accum_fb == NULL) {
     /* SSS is not enabled. */
     return;
   }
 
-  if ((view_layer->passflag & SCE_PASS_SUBSURFACE_COLOR) != 0) {
-    RenderPass *rp = RE_pass_find_by_name(rl, RE_PASSNAME_SUBSURFACE_COLOR, viewname);
-
-    GPU_framebuffer_bind(vedata->fbl->sss_accum_fb);
-    GPU_framebuffer_read_color(vedata->fbl->sss_accum_fb,
-                               vedata->stl->g_data->overscan_pixels + rect->xmin,
-                               vedata->stl->g_data->overscan_pixels + rect->ymin,
-                               BLI_rcti_size_x(rect),
-                               BLI_rcti_size_y(rect),
-                               3,
-                               1,
-                               rp->rect);
-
-    /* This is the accumulated color. Divide by the number of samples. */
-    for (int i = 0; i < rp->rectx * rp->recty * 3; i++) {
-      rp->rect[i] /= (float)render_samples;
-    }
+  if ((vedata->stl->g_data->render_passes & SCE_PASS_SUBSURFACE_COLOR) != 0) {
+    EEVEE_renderpasses_postprocess(sldata, vedata, SCE_PASS_SUBSURFACE_COLOR);
+    eevee_render_color_result(
+        rl, viewname, rect, RE_PASSNAME_SUBSURFACE_COLOR, 3, vedata->fbl->renderpass_fb, vedata);
   }
 
-  if ((view_layer->passflag & SCE_PASS_SUBSURFACE_DIRECT) != 0) {
-    RenderPass *rp = RE_pass_find_by_name(rl, RE_PASSNAME_SUBSURFACE_DIRECT, viewname);
-
-    GPU_framebuffer_bind(vedata->fbl->sss_accum_fb);
-    GPU_framebuffer_read_color(vedata->fbl->sss_accum_fb,
-                               vedata->stl->g_data->overscan_pixels + rect->xmin,
-                               vedata->stl->g_data->overscan_pixels + rect->ymin,
-                               BLI_rcti_size_x(rect),
-                               BLI_rcti_size_y(rect),
-                               3,
-                               0,
-                               rp->rect);
-
-    /* This is the accumulated color. Divide by the number of samples. */
-    for (int i = 0; i < rp->rectx * rp->recty * 3; i++) {
-      rp->rect[i] /= (float)render_samples;
-    }
+  if ((vedata->stl->g_data->render_passes & SCE_PASS_SUBSURFACE_DIRECT) != 0) {
+    EEVEE_renderpasses_postprocess(sldata, vedata, SCE_PASS_SUBSURFACE_DIRECT);
+    eevee_render_color_result(
+        rl, viewname, rect, RE_PASSNAME_SUBSURFACE_DIRECT, 3, vedata->fbl->renderpass_fb, vedata);
   }
 
-  if ((view_layer->passflag & SCE_PASS_SUBSURFACE_INDIRECT) != 0) {
+  if ((vedata->stl->g_data->render_passes & SCE_PASS_SUBSURFACE_INDIRECT) != 0) {
     /* Do nothing as all the lighting is in the direct pass.
      * TODO : Separate Direct from indirect lighting. */
   }
@@ -284,54 +267,19 @@ static void eevee_render_result_normal(RenderLayer *rl,
                                        const char *viewname,
                                        const rcti *rect,
                                        EEVEE_Data *vedata,
-                                       EEVEE_ViewLayerData *UNUSED(sldata))
+                                       EEVEE_ViewLayerData *sldata)
 {
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  ViewLayer *view_layer = draw_ctx->view_layer;
-  EEVEE_StorageList *stl = vedata->stl;
-  EEVEE_PrivateData *g_data = stl->g_data;
+  const int current_sample = vedata->stl->effects->taa_current_sample;
 
   /* Only read the center texel. */
-  if (stl->effects->taa_current_sample > 1) {
+  if (current_sample > 1) {
     return;
   }
 
-  if ((view_layer->passflag & SCE_PASS_NORMAL) != 0) {
-    RenderPass *rp = RE_pass_find_by_name(rl, RE_PASSNAME_NORMAL, viewname);
-
-    GPU_framebuffer_bind(vedata->fbl->main_fb);
-    GPU_framebuffer_read_color(vedata->fbl->main_fb,
-                               g_data->overscan_pixels + rect->xmin,
-                               g_data->overscan_pixels + rect->ymin,
-                               BLI_rcti_size_x(rect),
-                               BLI_rcti_size_y(rect),
-                               3,
-                               1,
-                               rp->rect);
-
-    float viewinv[4][4];
-    DRW_view_viewmat_get(NULL, viewinv, true);
-
-    /* Convert Eevee encoded normals to Blender normals. */
-    for (int i = 0; i < rp->rectx * rp->recty * 3; i += 3) {
-      if (rp->rect[i] == 0.0f && rp->rect[i + 1] == 0.0f) {
-        /* If normal is not correct then do not produce NANs.  */
-        continue;
-      }
-
-      float fenc[2];
-      fenc[0] = rp->rect[i + 0] * 4.0f - 2.0f;
-      fenc[1] = rp->rect[i + 1] * 4.0f - 2.0f;
-
-      float f = dot_v2v2(fenc, fenc);
-      float g = sqrtf(1.0f - f / 4.0f);
-
-      rp->rect[i + 0] = fenc[0] * g;
-      rp->rect[i + 1] = fenc[1] * g;
-      rp->rect[i + 2] = 1.0f - f / 2.0f;
-
-      mul_mat3_m4_v3(viewinv, &rp->rect[i]);
-    }
+  if ((vedata->stl->g_data->render_passes & SCE_PASS_NORMAL) != 0) {
+    EEVEE_renderpasses_postprocess(sldata, vedata, SCE_PASS_NORMAL);
+    eevee_render_color_result(
+        rl, viewname, rect, RE_PASSNAME_NORMAL, 3, vedata->fbl->renderpass_fb, vedata);
   }
 }
 
@@ -341,49 +289,17 @@ static void eevee_render_result_z(RenderLayer *rl,
                                   EEVEE_Data *vedata,
                                   EEVEE_ViewLayerData *sldata)
 {
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  ViewLayer *view_layer = draw_ctx->view_layer;
-  EEVEE_CommonUniformBuffer *common_data = &sldata->common_data;
-  EEVEE_StorageList *stl = vedata->stl;
-  EEVEE_PrivateData *g_data = stl->g_data;
+  const int current_sample = vedata->stl->effects->taa_current_sample;
 
   /* Only read the center texel. */
-  if (stl->effects->taa_current_sample > 1) {
+  if (current_sample > 1) {
     return;
   }
 
-  if ((view_layer->passflag & SCE_PASS_Z) != 0) {
-    RenderPass *rp = RE_pass_find_by_name(rl, RE_PASSNAME_Z, viewname);
-
-    GPU_framebuffer_bind(vedata->fbl->main_fb);
-    GPU_framebuffer_read_depth(vedata->fbl->main_fb,
-                               g_data->overscan_pixels + rect->xmin,
-                               g_data->overscan_pixels + rect->ymin,
-                               BLI_rcti_size_x(rect),
-                               BLI_rcti_size_y(rect),
-                               rp->rect);
-
-    bool is_persp = DRW_view_is_persp_get(NULL);
-
-    float winmat[4][4];
-    DRW_view_winmat_get(NULL, winmat, false);
-
-    /* Convert ogl depth [0..1] to view Z [near..far] */
-    for (int i = 0; i < rp->rectx * rp->recty; i++) {
-      if (rp->rect[i] == 1.0f) {
-        rp->rect[i] = 1e10f; /* Background */
-      }
-      else {
-        if (is_persp) {
-          rp->rect[i] = rp->rect[i] * 2.0f - 1.0f;
-          rp->rect[i] = winmat[3][2] / (rp->rect[i] + winmat[2][2]);
-        }
-        else {
-          rp->rect[i] = -common_data->view_vecs[0][2] +
-                        rp->rect[i] * -common_data->view_vecs[1][2];
-        }
-      }
-    }
+  if ((vedata->stl->g_data->render_passes & SCE_PASS_Z) != 0) {
+    EEVEE_renderpasses_postprocess(sldata, vedata, SCE_PASS_Z);
+    eevee_render_color_result(
+        rl, viewname, rect, RE_PASSNAME_Z, 1, vedata->fbl->renderpass_fb, vedata);
   }
 }
 
@@ -391,29 +307,12 @@ static void eevee_render_result_mist(RenderLayer *rl,
                                      const char *viewname,
                                      const rcti *rect,
                                      EEVEE_Data *vedata,
-                                     EEVEE_ViewLayerData *UNUSED(sldata),
-                                     int render_samples)
+                                     EEVEE_ViewLayerData *sldata)
 {
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  ViewLayer *view_layer = draw_ctx->view_layer;
-
-  if ((view_layer->passflag & SCE_PASS_MIST) != 0) {
-    RenderPass *rp = RE_pass_find_by_name(rl, RE_PASSNAME_MIST, viewname);
-
-    GPU_framebuffer_bind(vedata->fbl->mist_accum_fb);
-    GPU_framebuffer_read_color(vedata->fbl->mist_accum_fb,
-                               vedata->stl->g_data->overscan_pixels + rect->xmin,
-                               vedata->stl->g_data->overscan_pixels + rect->ymin,
-                               BLI_rcti_size_x(rect),
-                               BLI_rcti_size_y(rect),
-                               1,
-                               0,
-                               rp->rect);
-
-    /* This is the accumulated color. Divide by the number of samples. */
-    for (int i = 0; i < rp->rectx * rp->recty; i++) {
-      rp->rect[i] /= (float)render_samples;
-    }
+  if ((vedata->stl->g_data->render_passes & SCE_PASS_MIST) != 0) {
+    EEVEE_renderpasses_postprocess(sldata, vedata, SCE_PASS_MIST);
+    eevee_render_color_result(
+        rl, viewname, rect, RE_PASSNAME_MIST, 1, vedata->fbl->renderpass_fb, vedata);
   }
 }
 
@@ -421,35 +320,17 @@ static void eevee_render_result_occlusion(RenderLayer *rl,
                                           const char *viewname,
                                           const rcti *rect,
                                           EEVEE_Data *vedata,
-                                          EEVEE_ViewLayerData *UNUSED(sldata),
-                                          int render_samples)
+                                          EEVEE_ViewLayerData *sldata)
 {
-  const DRWContextState *draw_ctx = DRW_context_state_get();
-  ViewLayer *view_layer = draw_ctx->view_layer;
-
   if (vedata->fbl->ao_accum_fb == NULL) {
     /* AO is not enabled. */
     return;
   }
 
-  if ((view_layer->passflag & SCE_PASS_AO) != 0) {
-    RenderPass *rp = RE_pass_find_by_name(rl, RE_PASSNAME_AO, viewname);
-
-    GPU_framebuffer_bind(vedata->fbl->ao_accum_fb);
-    GPU_framebuffer_read_color(vedata->fbl->ao_accum_fb,
-                               vedata->stl->g_data->overscan_pixels + rect->xmin,
-                               vedata->stl->g_data->overscan_pixels + rect->ymin,
-                               BLI_rcti_size_x(rect),
-                               BLI_rcti_size_y(rect),
-                               3,
-                               0,
-                               rp->rect);
-
-    /* This is the accumulated color. Divide by the number of samples. */
-    for (int i = 0; i < rp->rectx * rp->recty * 3; i += 3) {
-      rp->rect[i] = rp->rect[i + 1] = rp->rect[i + 2] = min_ff(
-          1.0f, rp->rect[i] / (float)render_samples);
-    }
+  if ((vedata->stl->g_data->render_passes & SCE_PASS_AO) != 0) {
+    EEVEE_renderpasses_postprocess(sldata, vedata, SCE_PASS_AO);
+    eevee_render_color_result(
+        rl, viewname, rect, RE_PASSNAME_AO, 3, vedata->fbl->renderpass_fb, vedata);
   }
 }
 
@@ -488,7 +369,6 @@ void EEVEE_render_draw(EEVEE_Data *vedata, RenderEngine *engine, RenderLayer *rl
 {
   const DRWContextState *draw_ctx = DRW_context_state_get();
   const Scene *scene_eval = DEG_get_evaluated_scene(draw_ctx->depsgraph);
-  ViewLayer *view_layer = draw_ctx->view_layer;
   const char *viewname = RE_GetActiveRenderView(engine->re);
   EEVEE_PassList *psl = vedata->psl;
   EEVEE_StorageList *stl = vedata->stl;
@@ -525,18 +405,7 @@ void EEVEE_render_draw(EEVEE_Data *vedata, RenderEngine *engine, RenderLayer *rl
     tot_sample += 1;
   }
 
-  if ((view_layer->passflag & (SCE_PASS_SUBSURFACE_COLOR | SCE_PASS_SUBSURFACE_DIRECT |
-                               SCE_PASS_SUBSURFACE_INDIRECT)) != 0) {
-    EEVEE_subsurface_output_init(sldata, vedata, tot_sample);
-  }
-
-  if ((view_layer->passflag & SCE_PASS_MIST) != 0) {
-    EEVEE_mist_output_init(sldata, vedata);
-  }
-
-  if ((view_layer->passflag & SCE_PASS_AO) != 0) {
-    EEVEE_occlusion_output_init(sldata, vedata, tot_sample);
-  }
+  EEVEE_renderpasses_output_init(sldata, vedata, tot_sample);
 
   if (RE_engine_test_break(engine)) {
     return;
@@ -644,9 +513,9 @@ void EEVEE_render_draw(EEVEE_Data *vedata, RenderEngine *engine, RenderLayer *rl
   }
 
   eevee_render_result_combined(rl, viewname, rect, vedata, sldata);
-  eevee_render_result_subsurface(rl, viewname, rect, vedata, sldata, render_samples);
-  eevee_render_result_mist(rl, viewname, rect, vedata, sldata, render_samples);
-  eevee_render_result_occlusion(rl, viewname, rect, vedata, sldata, render_samples);
+  eevee_render_result_subsurface(rl, viewname, rect, vedata, sldata);
+  eevee_render_result_mist(rl, viewname, rect, vedata, sldata);
+  eevee_render_result_occlusion(rl, viewname, rect, vedata, sldata);
 
   /* Restore original viewport size. */
   DRW_render_viewport_size_set((int[2]){g_data->size_orig[0], g_data->size_orig[1]});