EEVEE: Refactor of eevee_material.c

These are the modifications:

-With DRW modification we reduce the number of passes we need to populate.
-Rename passes for consistent naming.
-Reduce complexity in code compilation
-Cleanup how renderpass accumulation passes are setup, using pass instances.
-Make sculpt mode compatible with shadows
-Make hair passes compatible with SSS
-Error shader and lookdev materials now use standalone materials.
-Support default shader (world and material) using a default nodetree internally.
-Change BLEND_CLIP to be emulated by gpu nodetree. Making less shader variations.
-Use BLI_memblock for cache memory allocation.
-Renderpasses are handled by switching a UBO ref bind.

One major hack in this patch is the use of modified pointer as ghash keys.
This rely on the assumption that the keys will never overlap because the
number of options per key will never be bigger than the pointed struct.

The use of one single nodetree to support default material is also a bit hacky
since it won't support concurent usage of this nodetree.
(see EEVEE_shader_default_surface_nodetree)

Another change is that objects with shader errors now appear solid magenta instead
of shaded magenta. This is only because of code reuse purpose but could be changed
if really needed.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D7642

1 files changed, 198 insertions, 0 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_lut_gen.c b/source/blender/draw/engines/eevee/eevee_lut_gen.c
new file mode 100644
index 00000000000..5f20d6fbfb8
--- /dev/null
+++ b/source/blender/draw/engines/eevee/eevee_lut_gen.c
@@ -0,0 +1,198 @@
+/*
+ * 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 2020, Blender Foundation.
+ */
+
+/** \file
+ * \ingroup draw_engine
+ *
+ * EEVEE LUT generation:
+ *
+ * Routine to generate the LUT used by eevee stored in eevee_lut.h
+ * Theses functions are not to be used in the final executable.
+ */
+
+#include "DRW_render.h"
+
+#include "BLI_alloca.h"
+#include "BLI_rand.h"
+#include "BLI_string_utils.h"
+
+extern char datatoc_bsdf_lut_frag_glsl[];
+extern char datatoc_btdf_lut_frag_glsl[];
+extern char datatoc_bsdf_common_lib_glsl[];
+extern char datatoc_bsdf_sampling_lib_glsl[];
+extern char datatoc_lightprobe_geom_glsl[];
+extern char datatoc_lightprobe_vert_glsl[];
+
+static struct GPUTexture *create_ggx_lut_texture(int UNUSED(w), int UNUSED(h))
+{
+  struct GPUTexture *tex;
+  struct GPUFrameBuffer *fb = NULL;
+  static float samples_len = 8192.0f;
+  static float inv_samples_len = 1.0f / 8192.0f;
+
+  char *lib_str = BLI_string_joinN(datatoc_bsdf_common_lib_glsl, datatoc_bsdf_sampling_lib_glsl);
+
+  struct GPUShader *sh = DRW_shader_create_with_lib(datatoc_lightprobe_vert_glsl,
+                                                    datatoc_lightprobe_geom_glsl,
+                                                    datatoc_bsdf_lut_frag_glsl,
+                                                    lib_str,
+                                                    "#define HAMMERSLEY_SIZE 8192\n"
+                                                    "#define BRDF_LUT_SIZE 64\n"
+                                                    "#define NOISE_SIZE 64\n");
+
+  DRWPass *pass = DRW_pass_create("LightProbe Filtering", DRW_STATE_WRITE_COLOR);
+  DRWShadingGroup *grp = DRW_shgroup_create(sh, pass);
+  DRW_shgroup_uniform_float(grp, "sampleCount", &samples_len, 1);
+  DRW_shgroup_uniform_float(grp, "invSampleCount", &inv_samples_len, 1);
+  DRW_shgroup_uniform_texture(grp, "texHammersley", e_data.hammersley);
+  DRW_shgroup_uniform_texture(grp, "texJitter", e_data.jitter);
+
+  struct GPUBatch *geom = DRW_cache_fullscreen_quad_get();
+  DRW_shgroup_call(grp, geom, NULL);
+
+  float *texels = MEM_mallocN(sizeof(float[2]) * w * h, "lut");
+
+  tex = DRW_texture_create_2d(w, h, GPU_RG16F, DRW_TEX_FILTER, (float *)texels);
+
+  DRWFboTexture tex_filter = {&tex, GPU_RG16F, DRW_TEX_FILTER};
+  GPU_framebuffer_init(&fb, &draw_engine_eevee_type, w, h, &tex_filter, 1);
+
+  GPU_framebuffer_bind(fb);
+  DRW_draw_pass(pass);
+
+  float *data = MEM_mallocN(sizeof(float[3]) * w * h, "lut");
+  glReadBuffer(GL_COLOR_ATTACHMENT0);
+  glReadPixels(0, 0, w, h, GL_RGB, GL_FLOAT, data);
+
+  printf("{");
+  for (int i = 0; i < w * h * 3; i += 3) {
+    printf("%ff, %ff, ", data[i], data[i + 1]);
+    i += 3;
+    printf("%ff, %ff, ", data[i], data[i + 1]);
+    i += 3;
+    printf("%ff, %ff, ", data[i], data[i + 1]);
+    i += 3;
+    printf("%ff, %ff, \n", data[i], data[i + 1]);
+  }
+  printf("}");
+
+  MEM_freeN(texels);
+  MEM_freeN(data);
+
+  return tex;
+}
+
+static struct GPUTexture *create_ggx_refraction_lut_texture(int w, int h)
+{
+  struct GPUTexture *tex;
+  struct GPUTexture *hammersley = create_hammersley_sample_texture(8192);
+  struct GPUFrameBuffer *fb = NULL;
+  static float samples_len = 8192.0f;
+  static float a2 = 0.0f;
+  static float inv_samples_len = 1.0f / 8192.0f;
+
+  char *frag_str = BLI_string_joinN(
+      datatoc_bsdf_common_lib_glsl, datatoc_bsdf_sampling_lib_glsl, datatoc_btdf_lut_frag_glsl);
+
+  struct GPUShader *sh = DRW_shader_create_fullscreen(frag_str,
+                                                      "#define HAMMERSLEY_SIZE 8192\n"
+                                                      "#define BRDF_LUT_SIZE 64\n"
+                                                      "#define NOISE_SIZE 64\n"
+                                                      "#define LUT_SIZE 64\n");
+
+  MEM_freeN(frag_str);
+
+  DRWPass *pass = DRW_pass_create("LightProbe Filtering", DRW_STATE_WRITE_COLOR);
+  DRWShadingGroup *grp = DRW_shgroup_create(sh, pass);
+  DRW_shgroup_uniform_float(grp, "a2", &a2, 1);
+  DRW_shgroup_uniform_float(grp, "sampleCount", &samples_len, 1);
+  DRW_shgroup_uniform_float(grp, "invSampleCount", &inv_samples_len, 1);
+  DRW_shgroup_uniform_texture(grp, "texHammersley", hammersley);
+  DRW_shgroup_uniform_texture(grp, "utilTex", e_data.util_tex);
+
+  struct GPUBatch *geom = DRW_cache_fullscreen_quad_get();
+  DRW_shgroup_call(grp, geom, NULL);
+
+  float *texels = MEM_mallocN(sizeof(float[2]) * w * h, "lut");
+
+  tex = DRW_texture_create_2d(w, h, GPU_R16F, DRW_TEX_FILTER, (float *)texels);
+
+  DRWFboTexture tex_filter = {&tex, GPU_R16F, DRW_TEX_FILTER};
+  GPU_framebuffer_init(&fb, &draw_engine_eevee_type, w, h, &tex_filter, 1);
+
+  GPU_framebuffer_bind(fb);
+
+  float *data = MEM_mallocN(sizeof(float[3]) * w * h, "lut");
+
+  float inc = 1.0f / 31.0f;
+  float roughness = 1e-8f - inc;
+  FILE *f = BLI_fopen("btdf_split_sum_ggx.h", "w");
+  fprintf(f, "static float btdf_split_sum_ggx[32][64 * 64] = {\n");
+  do {
+    roughness += inc;
+    CLAMP(roughness, 1e-4f, 1.0f);
+    a2 = powf(roughness, 4.0f);
+    DRW_draw_pass(pass);
+
+    GPU_framebuffer_read_data(0, 0, w, h, 3, 0, data);
+
+#if 1
+    fprintf(f, "\t{\n\t\t");
+    for (int i = 0; i < w * h * 3; i += 3) {
+      fprintf(f, "%ff,", data[i]);
+      if (((i / 3) + 1) % 12 == 0) {
+        fprintf(f, "\n\t\t");
+      }
+      else {
+        fprintf(f, " ");
+      }
+    }
+    fprintf(f, "\n\t},\n");
+#else
+    for (int i = 0; i < w * h * 3; i += 3) {
+      if (data[i] < 0.01) {
+        printf(" ");
+      }
+      else if (data[i] < 0.3) {
+        printf(".");
+      }
+      else if (data[i] < 0.6) {
+        printf("+");
+      }
+      else if (data[i] < 0.9) {
+        printf("%%");
+      }
+      else {
+        printf("#");
+      }
+      if ((i / 3 + 1) % 64 == 0) {
+        printf("\n");
+      }
+    }
+#endif
+
+  } while (roughness < 1.0f);
+  fprintf(f, "\n};\n");
+
+  fclose(f);
+
+  MEM_freeN(texels);
+  MEM_freeN(data);
+
+  return tex;
+}
\ No newline at end of file