Realtime Compositor: Add basic output nodes

This patch implements the following nodes for the realtime compositor:

- Composite node.
- Viewer node.
- Split viewer node.

Differential Revision: https://developer.blender.org/D15226

Reviewed By: Clement Foucault

11 files changed, 406 insertions, 0 deletions

diff --git a/source/blender/gpu/CMakeLists.txt b/source/blender/gpu/CMakeLists.txt
index dcb6788c4d8..c20fff7082e 100644
--- a/source/blender/gpu/CMakeLists.txt
+++ b/source/blender/gpu/CMakeLists.txt
@@ -325,6 +325,8 @@ set(GLSL_SRC
 
   shaders/compositor/compositor_convert.glsl
   shaders/compositor/compositor_realize_on_domain.glsl
+  shaders/compositor/compositor_set_alpha.glsl
+  shaders/compositor/compositor_split_viewer.glsl
 
   shaders/compositor/library/gpu_shader_compositor_main.glsl
   shaders/compositor/library/gpu_shader_compositor_store_output.glsl
@@ -538,6 +540,8 @@ set(SRC_SHADER_CREATE_INFOS
 
   shaders/compositor/infos/compositor_convert_info.hh
   shaders/compositor/infos/compositor_realize_on_domain_info.hh
+  shaders/compositor/infos/compositor_set_alpha_info.hh
+  shaders/compositor/infos/compositor_split_viewer_info.hh
 )
 
 set(SHADER_CREATE_INFOS_CONTENT "")
diff --git a/source/blender/gpu/shaders/compositor/compositor_set_alpha.glsl b/source/blender/gpu/shaders/compositor/compositor_set_alpha.glsl
new file mode 100644
index 00000000000..7dd40581790
--- /dev/null
+++ b/source/blender/gpu/shaders/compositor/compositor_set_alpha.glsl
@@ -0,0 +1,8 @@
+#pragma BLENDER_REQUIRE(gpu_shader_compositor_texture_utilities.glsl)
+
+void main()
+{
+  ivec2 texel = ivec2(gl_GlobalInvocationID.xy);
+  vec4 color = vec4(texture_load(image_tx, texel).rgb, texture_load(alpha_tx, texel).x);
+  imageStore(output_img, texel, color);
+}
diff --git a/source/blender/gpu/shaders/compositor/compositor_split_viewer.glsl b/source/blender/gpu/shaders/compositor/compositor_split_viewer.glsl
new file mode 100644
index 00000000000..866b9045da2
--- /dev/null
+++ b/source/blender/gpu/shaders/compositor/compositor_split_viewer.glsl
@@ -0,0 +1,14 @@
+#pragma BLENDER_REQUIRE(gpu_shader_compositor_texture_utilities.glsl)
+
+void main()
+{
+  ivec2 texel = ivec2(gl_GlobalInvocationID.xy);
+#if defined(SPLIT_HORIZONTAL)
+  bool condition = (view_size.x * split_ratio) < texel.x;
+#elif defined(SPLIT_VERTICAL)
+  bool condition = (view_size.y * split_ratio) < texel.y;
+#endif
+  vec4 color = condition ? texture_load(first_image_tx, texel) :
+                           texture_load(second_image_tx, texel);
+  imageStore(output_img, texel, color);
+}
diff --git a/source/blender/gpu/shaders/compositor/infos/compositor_convert_info.hh b/source/blender/gpu/shaders/compositor/infos/compositor_convert_info.hh
index 235525b582b..35e60056736 100644
--- a/source/blender/gpu/shaders/compositor/infos/compositor_convert_info.hh
+++ b/source/blender/gpu/shaders/compositor/infos/compositor_convert_info.hh
@@ -61,3 +61,9 @@ GPU_SHADER_CREATE_INFO(compositor_convert_float_to_half_float)
     .image(0, GPU_R16F, Qualifier::WRITE, ImageType::FLOAT_2D, "output_img")
     .define("CONVERT_EXPRESSION(value)", "vec4(value.r, vec3(0.0))")
     .do_static_compilation(true);
+
+GPU_SHADER_CREATE_INFO(compositor_convert_color_to_opaque)
+    .additional_info("compositor_convert_shared")
+    .image(0, GPU_RGBA16F, Qualifier::WRITE, ImageType::FLOAT_2D, "output_img")
+    .define("CONVERT_EXPRESSION(value)", "vec4(value.rgb, 1.0)")
+    .do_static_compilation(true);
diff --git a/source/blender/gpu/shaders/compositor/infos/compositor_set_alpha_info.hh b/source/blender/gpu/shaders/compositor/infos/compositor_set_alpha_info.hh
new file mode 100644
index 00000000000..ca28194e921
--- /dev/null
+++ b/source/blender/gpu/shaders/compositor/infos/compositor_set_alpha_info.hh
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "gpu_shader_create_info.hh"
+
+GPU_SHADER_CREATE_INFO(compositor_set_alpha)
+    .local_group_size(16, 16)
+    .sampler(0, ImageType::FLOAT_2D, "image_tx")
+    .sampler(1, ImageType::FLOAT_2D, "alpha_tx")
+    .image(0, GPU_RGBA16F, Qualifier::WRITE, ImageType::FLOAT_2D, "output_img")
+    .compute_source("compositor_set_alpha.glsl")
+    .do_static_compilation(true);
diff --git a/source/blender/gpu/shaders/compositor/infos/compositor_split_viewer_info.hh b/source/blender/gpu/shaders/compositor/infos/compositor_split_viewer_info.hh
new file mode 100644
index 00000000000..d5793b0ce59
--- /dev/null
+++ b/source/blender/gpu/shaders/compositor/infos/compositor_split_viewer_info.hh
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "gpu_shader_create_info.hh"
+
+GPU_SHADER_CREATE_INFO(compositor_split_viewer_shared)
+    .local_group_size(16, 16)
+    .push_constant(Type::FLOAT, "split_ratio")
+    .push_constant(Type::IVEC2, "view_size")
+    .sampler(0, ImageType::FLOAT_2D, "first_image_tx")
+    .sampler(1, ImageType::FLOAT_2D, "second_image_tx")
+    .image(0, GPU_RGBA16F, Qualifier::WRITE, ImageType::FLOAT_2D, "output_img")
+    .compute_source("compositor_split_viewer.glsl");
+
+GPU_SHADER_CREATE_INFO(compositor_split_viewer_horizontal)
+    .additional_info("compositor_split_viewer_shared")
+    .define("SPLIT_HORIZONTAL")
+    .do_static_compilation(true);
+
+GPU_SHADER_CREATE_INFO(compositor_split_viewer_vertical)
+    .additional_info("compositor_split_viewer_shared")
+    .define("SPLIT_VERTICAL")
+    .do_static_compilation(true);
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index 76d8207eead..d3c3b70808d 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -1838,6 +1838,12 @@ enum {
 /* viewer and composite output. */
 #define CMP_NODE_OUTPUT_IGNORE_ALPHA 1
 
+/* Split Viewer Node. Stored in custom2. */
+typedef enum CMPNodeSplitViewerAxis {
+  CMP_NODE_SPLIT_VIEWER_HORIZONTAL = 0,
+  CMP_NODE_SPLIT_VIEWER_VERTICAL = 1,
+} CMPNodeSplitViewerAxis;
+
 /* Plane track deform node. */
 
 enum {
diff --git a/source/blender/nodes/composite/CMakeLists.txt b/source/blender/nodes/composite/CMakeLists.txt
index 6b1522b7634..5034ddc4a30 100644
--- a/source/blender/nodes/composite/CMakeLists.txt
+++ b/source/blender/nodes/composite/CMakeLists.txt
@@ -10,11 +10,13 @@ set(INC
   ../../blenlib
   ../../blentranslation
   ../../depsgraph
+  ../../gpu
   ../../imbuf
   ../../makesdna
   ../../makesrna
   ../../render
   ../../windowmanager
+  ../../compositor/realtime_compositor
   ../../../../intern/guardedalloc
 
   # dna_type_offsets.h
@@ -120,6 +122,10 @@ set(SRC
   node_composite_util.hh
 )
 
+set(LIB
+  bf_realtime_compositor
+)
+
 if(WITH_IMAGE_OPENEXR)
   add_definitions(-DWITH_OPENEXR)
 endif()
diff --git a/source/blender/nodes/composite/nodes/node_composite_composite.cc b/source/blender/nodes/composite/nodes/node_composite_composite.cc
index d35ce7dc11a..68061bb434d 100644
--- a/source/blender/nodes/composite/nodes/node_composite_composite.cc
+++ b/source/blender/nodes/composite/nodes/node_composite_composite.cc
@@ -5,9 +5,18 @@
  * \ingroup cmpnodes
  */
 
+#include "BLI_math_vec_types.hh"
+
 #include "UI_interface.h"
 #include "UI_resources.h"
 
+#include "GPU_shader.h"
+#include "GPU_state.h"
+#include "GPU_texture.h"
+
+#include "COM_node_operation.hh"
+#include "COM_utilities.hh"
+
 #include "node_composite_util.hh"
 
 /* **************** COMPOSITE ******************** */
@@ -26,6 +35,125 @@ static void node_composit_buts_composite(uiLayout *layout, bContext *UNUSED(C),
   uiItemR(layout, ptr, "use_alpha", UI_ITEM_R_SPLIT_EMPTY_NAME, nullptr, ICON_NONE);
 }
 
+using namespace blender::realtime_compositor;
+
+class CompositeOperation : public NodeOperation {
+ public:
+  using NodeOperation::NodeOperation;
+
+  void execute() override
+  {
+    const Result &image = get_input("Image");
+    const Result &alpha = get_input("Alpha");
+
+    if (image.is_single_value() && alpha.is_single_value()) {
+      execute_clear();
+    }
+    else if (ignore_alpha()) {
+      execute_ignore_alpha();
+    }
+    else if (!node().input_by_identifier("Alpha")->is_logically_linked()) {
+      execute_copy();
+    }
+    else {
+      execute_set_alpha();
+    }
+  }
+
+  /* Executes when all inputs are single values, in which case, the output texture can just be
+   * cleared to the appropriate color. */
+  void execute_clear()
+  {
+    const Result &image = get_input("Image");
+    const Result &alpha = get_input("Alpha");
+
+    float4 color = image.get_color_value();
+    if (ignore_alpha()) {
+      color.w = 1.0f;
+    }
+    else if (node().input_by_identifier("Alpha")->is_logically_linked()) {
+      color.w = alpha.get_float_value();
+    }
+
+    GPU_texture_clear(context().get_output_texture(), GPU_DATA_FLOAT, color);
+  }
+
+  /* Executes when the alpha channel of the image is ignored. */
+  void execute_ignore_alpha()
+  {
+    GPUShader *shader = shader_manager().get("compositor_convert_color_to_opaque");
+    GPU_shader_bind(shader);
+
+    const Result &image = get_input("Image");
+    image.bind_as_texture(shader, "input_tx");
+
+    GPUTexture *output_texture = context().get_output_texture();
+    const int image_unit = GPU_shader_get_texture_binding(shader, "output_img");
+    GPU_texture_image_bind(output_texture, image_unit);
+
+    compute_dispatch_threads_at_least(shader, compute_domain().size);
+
+    image.unbind_as_texture();
+    GPU_texture_image_unbind(output_texture);
+    GPU_shader_unbind();
+  }
+
+  /* Executes when the image texture is written with no adjustments and can thus be copied directly
+   * to the output texture. */
+  void execute_copy()
+  {
+    const Result &image = get_input("Image");
+
+    /* Make sure any prior writes to the texture are reflected before copying it. */
+    GPU_memory_barrier(GPU_BARRIER_TEXTURE_UPDATE);
+
+    GPU_texture_copy(context().get_output_texture(), image.texture());
+  }
+
+  /* Executes when the alpha channel of the image is set as the value of the input alpha. */
+  void execute_set_alpha()
+  {
+    GPUShader *shader = shader_manager().get("compositor_set_alpha");
+    GPU_shader_bind(shader);
+
+    const Result &image = get_input("Image");
+    image.bind_as_texture(shader, "image_tx");
+
+    const Result &alpha = get_input("Alpha");
+    alpha.bind_as_texture(shader, "alpha_tx");
+
+    GPUTexture *output_texture = context().get_output_texture();
+    const int image_unit = GPU_shader_get_texture_binding(shader, "output_img");
+    GPU_texture_image_bind(output_texture, image_unit);
+
+    compute_dispatch_threads_at_least(shader, compute_domain().size);
+
+    image.unbind_as_texture();
+    alpha.unbind_as_texture();
+    GPU_texture_image_unbind(output_texture);
+    GPU_shader_unbind();
+  }
+
+  /* If true, the alpha channel of the image is set to 1, that is, it becomes opaque. If false, the
+   * alpha channel of the image is retained, but only if the alpha input is not linked. If the
+   * alpha input is linked, it the value of that input will be used as the alpha of the image. */
+  bool ignore_alpha()
+  {
+    return bnode().custom2 & CMP_NODE_OUTPUT_IGNORE_ALPHA;
+  }
+
+  /* The operation domain have the same dimensions of the output without any transformations. */
+  Domain compute_domain() override
+  {
+    return Domain(context().get_output_size());
+  }
+};
+
+static NodeOperation *get_compositor_operation(Context &context, DNode node)
+{
+  return new CompositeOperation(context, node);
+}
+
 }  // namespace blender::nodes::node_composite_composite_cc
 
 void register_node_type_cmp_composite()
@@ -37,6 +165,7 @@ void register_node_type_cmp_composite()
   cmp_node_type_base(&ntype, CMP_NODE_COMPOSITE, "Composite", NODE_CLASS_OUTPUT);
   ntype.declare = file_ns::cmp_node_composite_declare;
   ntype.draw_buttons = file_ns::node_composit_buts_composite;
+  ntype.get_compositor_operation = file_ns::get_compositor_operation;
   ntype.flag |= NODE_PREVIEW;
   ntype.no_muting = true;
 
diff --git a/source/blender/nodes/composite/nodes/node_composite_split_viewer.cc b/source/blender/nodes/composite/nodes/node_composite_split_viewer.cc
index ab325c4559f..085de69e63e 100644
--- a/source/blender/nodes/composite/nodes/node_composite_split_viewer.cc
+++ b/source/blender/nodes/composite/nodes/node_composite_split_viewer.cc
@@ -11,6 +11,12 @@
 #include "UI_interface.h"
 #include "UI_resources.h"
 
+#include "GPU_shader.h"
+#include "GPU_texture.h"
+
+#include "COM_node_operation.hh"
+#include "COM_utilities.hh"
+
 #include "node_composite_util.hh"
 
 /* **************** SPLIT VIEWER ******************** */
@@ -43,6 +49,70 @@ static void node_composit_buts_splitviewer(uiLayout *layout, bContext *UNUSED(C)
   uiItemR(col, ptr, "factor", UI_ITEM_R_SPLIT_EMPTY_NAME, nullptr, ICON_NONE);
 }
 
+using namespace blender::realtime_compositor;
+
+class ViewerOperation : public NodeOperation {
+ public:
+  using NodeOperation::NodeOperation;
+
+  void execute() override
+  {
+    GPUShader *shader = get_split_viewer_shader();
+    GPU_shader_bind(shader);
+
+    const int2 size = compute_domain().size;
+
+    GPU_shader_uniform_1f(shader, "split_ratio", get_split_ratio());
+    GPU_shader_uniform_2iv(shader, "view_size", size);
+
+    const Result &first_image = get_input("Image");
+    first_image.bind_as_texture(shader, "first_image_tx");
+    const Result &second_image = get_input("Image_001");
+    second_image.bind_as_texture(shader, "second_image_tx");
+
+    GPUTexture *output_texture = context().get_output_texture();
+    const int image_unit = GPU_shader_get_texture_binding(shader, "output_img");
+    GPU_texture_image_bind(output_texture, image_unit);
+
+    compute_dispatch_threads_at_least(shader, size);
+
+    first_image.unbind_as_texture();
+    second_image.unbind_as_texture();
+    GPU_texture_image_unbind(output_texture);
+    GPU_shader_unbind();
+  }
+
+  /* The operation domain have the same dimensions of the output without any transformations. */
+  Domain compute_domain() override
+  {
+    return Domain(context().get_output_size());
+  }
+
+  GPUShader *get_split_viewer_shader()
+  {
+    if (get_split_axis() == CMP_NODE_SPLIT_VIEWER_HORIZONTAL) {
+      return shader_manager().get("compositor_split_viewer_horizontal");
+    }
+
+    return shader_manager().get("compositor_split_viewer_vertical");
+  }
+
+  CMPNodeSplitViewerAxis get_split_axis()
+  {
+    return (CMPNodeSplitViewerAxis)bnode().custom2;
+  }
+
+  float get_split_ratio()
+  {
+    return bnode().custom1 / 100.0f;
+  }
+};
+
+static NodeOperation *get_compositor_operation(Context &context, DNode node)
+{
+  return new ViewerOperation(context, node);
+}
+
 }  // namespace blender::nodes::node_composite_split_viewer_cc
 
 void register_node_type_cmp_splitviewer()
@@ -57,6 +127,7 @@ void register_node_type_cmp_splitviewer()
   ntype.flag |= NODE_PREVIEW;
   node_type_init(&ntype, file_ns::node_composit_init_splitviewer);
   node_type_storage(&ntype, "ImageUser", node_free_standard_storage, node_copy_standard_storage);
+  ntype.get_compositor_operation = file_ns::get_compositor_operation;
 
   ntype.no_muting = true;
 
diff --git a/source/blender/nodes/composite/nodes/node_composite_viewer.cc b/source/blender/nodes/composite/nodes/node_composite_viewer.cc
index 05f395183b5..4e82b31ca47 100644
--- a/source/blender/nodes/composite/nodes/node_composite_viewer.cc
+++ b/source/blender/nodes/composite/nodes/node_composite_viewer.cc
@@ -5,6 +5,8 @@
  * \ingroup cmpnodes
  */
 
+#include "BLI_math_vec_types.hh"
+
 #include "BKE_global.h"
 #include "BKE_image.h"
 
@@ -13,6 +15,13 @@
 #include "UI_interface.h"
 #include "UI_resources.h"
 
+#include "GPU_shader.h"
+#include "GPU_state.h"
+#include "GPU_texture.h"
+
+#include "COM_node_operation.hh"
+#include "COM_utilities.hh"
+
 #include "node_composite_util.hh"
 
 /* **************** VIEWER ******************** */
@@ -55,6 +64,125 @@ static void node_composit_buts_viewer_ex(uiLayout *layout, bContext *UNUSED(C),
   }
 }
 
+using namespace blender::realtime_compositor;
+
+class ViewerOperation : public NodeOperation {
+ public:
+  using NodeOperation::NodeOperation;
+
+  void execute() override
+  {
+    const Result &image = get_input("Image");
+    const Result &alpha = get_input("Alpha");
+
+    if (image.is_single_value() && alpha.is_single_value()) {
+      execute_clear();
+    }
+    else if (ignore_alpha()) {
+      execute_ignore_alpha();
+    }
+    else if (!node().input_by_identifier("Alpha")->is_logically_linked()) {
+      execute_copy();
+    }
+    else {
+      execute_set_alpha();
+    }
+  }
+
+  /* Executes when all inputs are single values, in which case, the output texture can just be
+   * cleared to the appropriate color. */
+  void execute_clear()
+  {
+    const Result &image = get_input("Image");
+    const Result &alpha = get_input("Alpha");
+
+    float4 color = image.get_color_value();
+    if (ignore_alpha()) {
+      color.w = 1.0f;
+    }
+    else if (node().input_by_identifier("Alpha")->is_logically_linked()) {
+      color.w = alpha.get_float_value();
+    }
+
+    GPU_texture_clear(context().get_output_texture(), GPU_DATA_FLOAT, color);
+  }
+
+  /* Executes when the alpha channel of the image is ignored. */
+  void execute_ignore_alpha()
+  {
+    GPUShader *shader = shader_manager().get("compositor_convert_color_to_opaque");
+    GPU_shader_bind(shader);
+
+    const Result &image = get_input("Image");
+    image.bind_as_texture(shader, "input_tx");
+
+    GPUTexture *output_texture = context().get_output_texture();
+    const int image_unit = GPU_shader_get_texture_binding(shader, "output_img");
+    GPU_texture_image_bind(output_texture, image_unit);
+
+    compute_dispatch_threads_at_least(shader, compute_domain().size);
+
+    image.unbind_as_texture();
+    GPU_texture_image_unbind(output_texture);
+    GPU_shader_unbind();
+  }
+
+  /* Executes when the image texture is written with no adjustments and can thus be copied directly
+   * to the output texture. */
+  void execute_copy()
+  {
+    const Result &image = get_input("Image");
+
+    /* Make sure any prior writes to the texture are reflected before copying it. */
+    GPU_memory_barrier(GPU_BARRIER_TEXTURE_UPDATE);
+
+    GPU_texture_copy(context().get_output_texture(), image.texture());
+  }
+
+  /* Executes when the alpha channel of the image is set as the value of the input alpha. */
+  void execute_set_alpha()
+  {
+    GPUShader *shader = shader_manager().get("compositor_set_alpha");
+    GPU_shader_bind(shader);
+
+    const Result &image = get_input("Image");
+    image.bind_as_texture(shader, "image_tx");
+
+    const Result &alpha = get_input("Alpha");
+    alpha.bind_as_texture(shader, "alpha_tx");
+
+    GPUTexture *output_texture = context().get_output_texture();
+    const int image_unit = GPU_shader_get_texture_binding(shader, "output_img");
+    GPU_texture_image_bind(output_texture, image_unit);
+
+    compute_dispatch_threads_at_least(shader, compute_domain().size);
+
+    image.unbind_as_texture();
+    alpha.unbind_as_texture();
+    GPU_texture_image_unbind(output_texture);
+    GPU_shader_unbind();
+  }
+
+  /* If true, the alpha channel of the image is set to 1, that is, it becomes opaque. If false, the
+   * alpha channel of the image is retained, but only if the alpha input is not linked. If the
+   * alpha input is linked, it the value of that input will be used as the alpha of the image. */
+  bool ignore_alpha()
+  {
+    return bnode().custom2 & CMP_NODE_OUTPUT_IGNORE_ALPHA;
+  }
+
+  /* The operation domain have the same dimensions of the output without any transformations. */
+  Domain compute_domain() override
+  {
+    return Domain(context().get_output_size());
+  }
+};
+
+static NodeOperation *get_compositor_operation(Context &context, DNode node)
+{
+  return new ViewerOperation(context, node);
+}
+
 }  // namespace blender::nodes::node_composite_viewer_cc
 
 void register_node_type_cmp_viewer()
@@ -70,6 +198,7 @@ void register_node_type_cmp_viewer()
   ntype.flag |= NODE_PREVIEW;
   node_type_init(&ntype, file_ns::node_composit_init_viewer);
   node_type_storage(&ntype, "ImageUser", node_free_standard_storage, node_copy_standard_storage);
+  ntype.get_compositor_operation = file_ns::get_compositor_operation;
 
   ntype.no_muting = true;