Draw: Added testcases for hair refine shaders.

7 files changed, 220 insertions, 95 deletions

diff --git a/source/blender/draw/CMakeLists.txt b/source/blender/draw/CMakeLists.txt
index e99bf1f5b0c..4f68c3fdc7e 100644
--- a/source/blender/draw/CMakeLists.txt
+++ b/source/blender/draw/CMakeLists.txt
@@ -85,6 +85,7 @@ set(SRC
   intern/draw_manager_text.c
   intern/draw_manager_texture.c
   intern/draw_select_buffer.c
+  intern/draw_shader.c
   intern/draw_view.c
   engines/basic/basic_engine.c
   engines/image/image_engine.c
@@ -185,6 +186,7 @@ set(SRC
   intern/draw_manager_testing.h
   intern/draw_manager_text.h
   intern/draw_view.h
+  intern/draw_shader.h
   intern/smaa_textures.h
   engines/basic/basic_engine.h
   engines/eevee/eevee_engine.h
diff --git a/source/blender/draw/intern/draw_hair.c b/source/blender/draw/intern/draw_hair.c
index 585e171adc5..d101df737ff 100644
--- a/source/blender/draw/intern/draw_hair.c
+++ b/source/blender/draw/intern/draw_hair.c
@@ -43,26 +43,26 @@
 #include "GPU_vertex_buffer.h"
 
 #include "draw_hair_private.h"
+#include "draw_shader.h"
 
 #ifndef __APPLE__
 #  define USE_TRANSFORM_FEEDBACK
 #  define USE_COMPUTE_SHADERS
 #endif
 
-BLI_INLINE bool drw_hair_use_compute_shaders(void)
+BLI_INLINE eParticleRefineShaderType drw_hair_shader_type_get(void)
 {
 #ifdef USE_COMPUTE_SHADERS
-  return GPU_compute_shader_support();
-#else
-  return false;
+  if (GPU_compute_shader_support()) {
+    return PART_REFINE_SHADER_COMPUTE;
+  }
 #endif
+#ifdef USE_TRANSFORM_FEEDBACK
+  return PART_REFINE_SHADER_TRANSFORM_FEEDBACK;
+#endif
+  return PART_REFINE_SHADER_TRANSFORM_FEEDBACK_WORKAROUND;
 }
 
-typedef enum ParticleRefineShader {
-  PART_REFINE_CATMULL_ROM = 0,
-  PART_REFINE_MAX_SHADER,
-} ParticleRefineShader;
-
 #ifndef USE_TRANSFORM_FEEDBACK
 typedef struct ParticleRefineCall {
   struct ParticleRefineCall *next;
@@ -79,89 +79,11 @@ static int g_tf_target_height;
 
 static GPUVertBuf *g_dummy_vbo = NULL;
 static GPUTexture *g_dummy_texture = NULL;
-static GPUShader *g_refine_shaders[PART_REFINE_MAX_SHADER] = {NULL};
 static DRWPass *g_tf_pass; /* XXX can be a problem with multiple DRWManager in the future */
 
-extern char datatoc_common_hair_lib_glsl[];
-extern char datatoc_common_hair_refine_vert_glsl[];
-extern char datatoc_common_hair_refine_comp_glsl[];
-extern char datatoc_gpu_shader_3D_smooth_color_frag_glsl[];
-
-/* TODO(jbakker): move shader creation to `draw_shaders` and add test cases. */
-/* TODO(jbakker): replace defines with `constexpr` to check compilation on all OS's.
- * Currently the `__APPLE__` code-path does not compile on other platforms and vice versa. */
-#ifdef USE_COMPUTE_SHADERS
-static GPUShader *hair_refine_shader_compute_create(ParticleRefineShader UNUSED(refinement))
-{
-  GPUShader *sh = NULL;
-  sh = GPU_shader_create_compute(datatoc_common_hair_refine_comp_glsl,
-                                 datatoc_common_hair_lib_glsl,
-                                 "#define HAIR_PHASE_SUBDIV\n",
-                                 __func__);
-  return sh;
-}
-#endif
-
-#ifdef USE_TRANSFORM_FEEDBACK
-static GPUShader *hair_refine_shader_transform_feedback_create(
-    ParticleRefineShader UNUSED(refinement))
-{
-  GPUShader *sh = NULL;
-
-  char *shader_src = BLI_string_joinN(datatoc_common_hair_lib_glsl,
-                                      datatoc_common_hair_refine_vert_glsl);
-  const char *var_names[1] = {"finalColor"};
-  sh = DRW_shader_create_with_transform_feedback(
-      shader_src, NULL, "#define HAIR_PHASE_SUBDIV\n", GPU_SHADER_TFB_POINTS, var_names, 1);
-  MEM_freeN(shader_src);
-
-  return sh;
-}
-#endif
-
-static GPUShader *hair_refine_shader_transform_feedback_workaround_create(
-    ParticleRefineShader UNUSED(refinement))
-{
-  GPUShader *sh = NULL;
-
-  char *shader_src = BLI_string_joinN(datatoc_common_hair_lib_glsl,
-                                      datatoc_common_hair_refine_vert_glsl);
-  sh = DRW_shader_create(shader_src,
-                         NULL,
-                         datatoc_gpu_shader_3D_smooth_color_frag_glsl,
-                         "#define blender_srgb_to_framebuffer_space(a) a\n"
-                         "#define HAIR_PHASE_SUBDIV\n"
-                         "#define TF_WORKAROUND\n");
-  MEM_freeN(shader_src);
-
-  return sh;
-}
-
 static GPUShader *hair_refine_shader_get(ParticleRefineShader refinement)
 {
-  if (g_refine_shaders[refinement]) {
-    return g_refine_shaders[refinement];
-  }
-
-#ifdef USE_COMPUTE_SHADERS
-  if (drw_hair_use_compute_shaders()) {
-    g_refine_shaders[refinement] = hair_refine_shader_compute_create(refinement);
-    if (g_refine_shaders[refinement]) {
-      return g_refine_shaders[refinement];
-    }
-  }
-#endif
-
-#ifdef USE_TRANSFORM_FEEDBACK
-  g_refine_shaders[refinement] = hair_refine_shader_transform_feedback_create(refinement);
-  if (g_refine_shaders[refinement]) {
-    return g_refine_shaders[refinement];
-  }
-#endif
-
-  g_refine_shaders[refinement] = hair_refine_shader_transform_feedback_workaround_create(
-      refinement);
-  return g_refine_shaders[refinement];
+  return DRW_shader_hair_refine_get(refinement, drw_hair_shader_type_get());
 }
 
 void DRW_hair_init(void)
@@ -265,7 +187,7 @@ static ParticleHairCache *drw_hair_particle_cache_get(
   }
 
   if (update) {
-    if (drw_hair_use_compute_shaders()) {
+    if (drw_hair_shader_type_get() == PART_REFINE_SHADER_COMPUTE) {
       drw_hair_particle_cache_update_compute(cache, subdiv);
     }
     else {
@@ -473,7 +395,7 @@ void DRW_hair_update(void)
 #else
   /* Just render the pass when using compute shaders or transform feedback. */
   DRW_draw_pass(g_tf_pass);
-  if (drw_hair_use_compute_shaders()) {
+  if (drw_hair_shader_type_get() == PART_REFINE_SHADER_COMPUTE) {
     GPU_memory_barrier(GPU_BARRIER_SHADER_STORAGE);
   }
 #endif
@@ -481,10 +403,6 @@ void DRW_hair_update(void)
 
 void DRW_hair_free(void)
 {
-  for (int i = 0; i < PART_REFINE_MAX_SHADER; i++) {
-    DRW_SHADER_FREE_SAFE(g_refine_shaders[i]);
-  }
-
   GPU_VERTBUF_DISCARD_SAFE(g_dummy_vbo);
   DRW_TEXTURE_FREE_SAFE(g_dummy_texture);
 }
diff --git a/source/blender/draw/intern/draw_hair_private.h b/source/blender/draw/intern/draw_hair_private.h
index 28bd5d4dfb5..1f58d8d0ead 100644
--- a/source/blender/draw/intern/draw_hair_private.h
+++ b/source/blender/draw/intern/draw_hair_private.h
@@ -23,11 +23,20 @@
 
 #pragma once
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define MAX_LAYER_NAME_CT 4 /* u0123456789, u, au, a0123456789 */
 #define MAX_LAYER_NAME_LEN (GPU_MAX_SAFE_ATTR_NAME + 2)
 #define MAX_THICKRES 2    /* see eHairType */
 #define MAX_HAIR_SUBDIV 4 /* see hair_subdiv rna */
 
+typedef enum ParticleRefineShader {
+  PART_REFINE_CATMULL_ROM = 0,
+  PART_REFINE_MAX_SHADER,
+} ParticleRefineShader;
+
 struct ModifierData;
 struct Object;
 struct ParticleHairCache;
@@ -91,3 +100,7 @@ bool hair_ensure_procedural_data(struct Object *object,
                                  struct ParticleHairCache **r_hair_cache,
                                  int subdiv,
                                  int thickness_res);
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/draw/intern/draw_manager.c b/source/blender/draw/intern/draw_manager.c
index 37f6bbf52b5..8a805409b27 100644
--- a/source/blender/draw/intern/draw_manager.c
+++ b/source/blender/draw/intern/draw_manager.c
@@ -87,6 +87,7 @@
 #include "draw_manager_profiling.h"
 #include "draw_manager_testing.h"
 #include "draw_manager_text.h"
+#include "draw_shader.h"
 
 /* only for callbacks */
 #include "draw_cache_impl.h"
@@ -2987,6 +2988,7 @@ void DRW_engines_free(void)
   DRW_TEXTURE_FREE_SAFE(g_select_buffer.texture_depth);
   GPU_FRAMEBUFFER_FREE_SAFE(g_select_buffer.framebuffer_depth_only);
 
+  DRW_shaders_free();
   DRW_hair_free();
   DRW_shape_cache_free();
   DRW_stats_free();
diff --git a/source/blender/draw/intern/draw_shader.c b/source/blender/draw/intern/draw_shader.c
new file mode 100644
index 00000000000..9c756065353
--- /dev/null
+++ b/source/blender/draw/intern/draw_shader.c
@@ -0,0 +1,122 @@
+/*
+ * 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
+ */
+
+#include "DRW_render.h"
+
+#include "BLI_dynstr.h"
+#include "BLI_string_utils.h"
+
+#include "GPU_batch.h"
+#include "GPU_index_buffer.h"
+#include "GPU_vertex_buffer.h"
+
+#include "draw_shader.h"
+
+extern char datatoc_common_hair_lib_glsl[];
+
+extern char datatoc_common_hair_refine_vert_glsl[];
+extern char datatoc_common_hair_refine_comp_glsl[];
+extern char datatoc_gpu_shader_3D_smooth_color_frag_glsl[];
+
+static struct {
+  struct GPUShader *hair_refine_sh[PART_REFINE_MAX_SHADER];
+} e_data = {{NULL}};
+
+/* -------------------------------------------------------------------- */
+/** \name Hair refinement
+ * \{ */
+
+static GPUShader *hair_refine_shader_compute_create(ParticleRefineShader UNUSED(refinement))
+{
+  GPUShader *sh = NULL;
+  sh = GPU_shader_create_compute(datatoc_common_hair_refine_comp_glsl,
+                                 datatoc_common_hair_lib_glsl,
+                                 "#define HAIR_PHASE_SUBDIV\n",
+                                 __func__);
+  return sh;
+}
+
+static GPUShader *hair_refine_shader_transform_feedback_create(
+    ParticleRefineShader UNUSED(refinement))
+{
+  GPUShader *sh = NULL;
+
+  char *shader_src = BLI_string_joinN(datatoc_common_hair_lib_glsl,
+                                      datatoc_common_hair_refine_vert_glsl);
+  const char *var_names[1] = {"finalColor"};
+  sh = DRW_shader_create_with_transform_feedback(
+      shader_src, NULL, "#define HAIR_PHASE_SUBDIV\n", GPU_SHADER_TFB_POINTS, var_names, 1);
+  MEM_freeN(shader_src);
+
+  return sh;
+}
+
+static GPUShader *hair_refine_shader_transform_feedback_workaround_create(
+    ParticleRefineShader UNUSED(refinement))
+{
+  GPUShader *sh = NULL;
+
+  char *shader_src = BLI_string_joinN(datatoc_common_hair_lib_glsl,
+                                      datatoc_common_hair_refine_vert_glsl);
+  sh = DRW_shader_create(shader_src,
+                         NULL,
+                         datatoc_gpu_shader_3D_smooth_color_frag_glsl,
+                         "#define blender_srgb_to_framebuffer_space(a) a\n"
+                         "#define HAIR_PHASE_SUBDIV\n"
+                         "#define TF_WORKAROUND\n");
+  MEM_freeN(shader_src);
+
+  return sh;
+}
+
+GPUShader *DRW_shader_hair_refine_get(ParticleRefineShader refinement,
+                                      eParticleRefineShaderType sh_type)
+{
+  if (e_data.hair_refine_sh[refinement] == NULL) {
+    GPUShader *sh = NULL;
+    switch (sh_type) {
+      case PART_REFINE_SHADER_COMPUTE:
+        sh = hair_refine_shader_compute_create(refinement);
+        break;
+      case PART_REFINE_SHADER_TRANSFORM_FEEDBACK:
+        sh = hair_refine_shader_transform_feedback_create(refinement);
+        break;
+      case PART_REFINE_SHADER_TRANSFORM_FEEDBACK_WORKAROUND:
+        sh = hair_refine_shader_transform_feedback_workaround_create(refinement);
+        break;
+      default:
+        BLI_assert(!"Incorrect shader type");
+    }
+    e_data.hair_refine_sh[refinement] = sh;
+  }
+
+  return e_data.hair_refine_sh[refinement];
+}
+
+/** \} */
+
+void DRW_shaders_free(void)
+{
+  for (int i = 0; i < PART_REFINE_MAX_SHADER; i++) {
+    DRW_SHADER_FREE_SAFE(e_data.hair_refine_sh[i]);
+  }
+}
diff --git a/source/blender/draw/intern/draw_shader.h b/source/blender/draw/intern/draw_shader.h
new file mode 100644
index 00000000000..f9fa452671b
--- /dev/null
+++ b/source/blender/draw/intern/draw_shader.h
@@ -0,0 +1,47 @@
+/*
+ * 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) 2021 by Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup draw
+ */
+
+#pragma once
+
+#include "draw_hair_private.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct GPUShader;
+
+typedef enum eParticleRefineShaderType {
+  PART_REFINE_SHADER_TRANSFORM_FEEDBACK,
+  PART_REFINE_SHADER_TRANSFORM_FEEDBACK_WORKAROUND,
+  PART_REFINE_SHADER_COMPUTE,
+} eParticleRefineShaderType;
+
+/* draw_shader.c */
+struct GPUShader *DRW_shader_hair_refine_get(ParticleRefineShader refinement,
+                                             eParticleRefineShaderType sh_type);
+void DRW_shaders_free(void);
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/source/blender/draw/tests/shaders_test.cc b/source/blender/draw/tests/shaders_test.cc
index c96f22859ca..cce69714f5e 100644
--- a/source/blender/draw/tests/shaders_test.cc
+++ b/source/blender/draw/tests/shaders_test.cc
@@ -3,17 +3,22 @@
 #include "testing/testing.h"
 
 #include "draw_testing.hh"
-#include "intern/draw_manager_testing.h"
 
 #include "GPU_context.h"
+#include "GPU_index_buffer.h"
 #include "GPU_init_exit.h"
 #include "GPU_shader.h"
+#include "GPU_texture.h"
+#include "GPU_vertex_buffer.h"
+
+#include "intern/draw_manager_testing.h"
 
 #include "engines/eevee/eevee_private.h"
 #include "engines/gpencil/gpencil_engine.h"
 #include "engines/image/image_private.h"
 #include "engines/overlay/overlay_private.h"
 #include "engines/workbench/workbench_private.h"
+#include "intern/draw_shader.h"
 
 namespace blender::draw {
 
@@ -366,4 +371,20 @@ TEST_F(DrawTest, eevee_glsl_shaders_static)
   EEVEE_shaders_free();
 }
 
+static void test_draw_shaders(eParticleRefineShaderType sh_type)
+{
+  DRW_shaders_free();
+  EXPECT_NE(DRW_shader_hair_refine_get(PART_REFINE_CATMULL_ROM, sh_type), nullptr);
+  DRW_shaders_free();
+}
+
+TEST_F(DrawTest, draw_glsl_shaders)
+{
+#ifndef __APPLE__
+  test_draw_shaders(PART_REFINE_SHADER_TRANSFORM_FEEDBACK);
+  test_draw_shaders(PART_REFINE_SHADER_COMPUTE);
+#endif
+  test_draw_shaders(PART_REFINE_SHADER_TRANSFORM_FEEDBACK_WORKAROUND);
+}
+
 }  // namespace blender::draw