GPencil: Refactor of Draw Engine, Vertex Paint and all internal functions

This commit is a full refactor of the grease pencil modules including Draw Engine, Modifiers, VFX, depsgraph update, improvements in operators and conversion of Sculpt and Weight paint tools to real brushes.

Also, a huge code cleanup has been done at all levels.

Thanks to @fclem for his work and yo @pepeland and @mendio for the testing and help in the development.

Differential Revision: https://developer.blender.org/D6293

7 files changed, 63 insertions, 0 deletions

diff --git a/source/blender/gpu/GPU_framebuffer.h b/source/blender/gpu/GPU_framebuffer.h
index 7d0f8b0bcbf..213cbe30794 100644
--- a/source/blender/gpu/GPU_framebuffer.h
+++ b/source/blender/gpu/GPU_framebuffer.h
@@ -173,6 +173,8 @@ void GPU_framebuffer_clear(GPUFrameBuffer *fb,
 #define GPU_framebuffer_clear_color_depth_stencil(fb, col, depth, stencil) \
   GPU_framebuffer_clear(fb, GPU_COLOR_BIT | GPU_DEPTH_BIT | GPU_STENCIL_BIT, col, depth, stencil)
 
+void GPU_framebuffer_multi_clear(GPUFrameBuffer *fb, const float (*clear_cols)[4]);
+
 void GPU_framebuffer_read_depth(GPUFrameBuffer *fb, int x, int y, int w, int h, float *data);
 void GPU_framebuffer_read_color(
     GPUFrameBuffer *fb, int x, int y, int w, int h, int channels, int slot, float *data);
diff --git a/source/blender/gpu/GPU_shader_interface.h b/source/blender/gpu/GPU_shader_interface.h
index c636135d75b..8b0d25e51a3 100644
--- a/source/blender/gpu/GPU_shader_interface.h
+++ b/source/blender/gpu/GPU_shader_interface.h
@@ -55,6 +55,7 @@ typedef enum {
   GPU_UNIFORM_COLOR,          /* vec4 color */
   GPU_UNIFORM_BASE_INSTANCE,  /* int baseInstance */
   GPU_UNIFORM_RESOURCE_CHUNK, /* int resourceChunk */
+  GPU_UNIFORM_RESOURCE_ID,    /* int resourceId */
 
   GPU_UNIFORM_CUSTOM, /* custom uniform, not one of the above built-ins */
 
diff --git a/source/blender/gpu/GPU_texture.h b/source/blender/gpu/GPU_texture.h
index 338f4d906f6..50b7c23059d 100644
--- a/source/blender/gpu/GPU_texture.h
+++ b/source/blender/gpu/GPU_texture.h
@@ -95,6 +95,7 @@ typedef enum eGPUTextureFormat {
 #if 0
   GPU_RGB10_A2,
   GPU_RGB10_A2UI,
+  GPU_SRGB8_A8,
 #endif
   GPU_R11F_G11F_B10F,
   GPU_DEPTH32F_STENCIL8,
diff --git a/source/blender/gpu/GPU_vertex_format.h b/source/blender/gpu/GPU_vertex_format.h
index cbc20f37f27..f5717645bc1 100644
--- a/source/blender/gpu/GPU_vertex_format.h
+++ b/source/blender/gpu/GPU_vertex_format.h
@@ -112,6 +112,8 @@ uint GPU_vertformat_attr_add(
     GPUVertFormat *, const char *name, GPUVertCompType, uint comp_len, GPUVertFetchMode);
 void GPU_vertformat_alias_add(GPUVertFormat *, const char *alias);
 
+void GPU_vertformat_multiload_enable(GPUVertFormat *format, int load_count);
+
 void GPU_vertformat_deinterleave(GPUVertFormat *format);
 
 int GPU_vertformat_attr_id_get(const GPUVertFormat *, const char *name);
diff --git a/source/blender/gpu/intern/gpu_framebuffer.c b/source/blender/gpu/intern/gpu_framebuffer.c
index b0fbb0eae49..6197d5f99b8 100644
--- a/source/blender/gpu/intern/gpu_framebuffer.c
+++ b/source/blender/gpu/intern/gpu_framebuffer.c
@@ -614,6 +614,21 @@ void GPU_framebuffer_clear(GPUFrameBuffer *fb,
   glClear(mask);
 }
 
+/* Clear all textures bound to this framebuffer with a different color. */
+void GPU_framebuffer_multi_clear(GPUFrameBuffer *fb, const float (*clear_cols)[4])
+{
+  CHECK_FRAMEBUFFER_IS_BOUND(fb);
+
+  glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
+
+  GPUAttachmentType type = GPU_FB_COLOR_ATTACHMENT0;
+  for (int i = 0; type < GPU_FB_MAX_ATTACHEMENT; i++, type++) {
+    if (fb->attachments[type].tex != NULL) {
+      glClearBufferfv(GL_COLOR, i, clear_cols[i]);
+    }
+  }
+}
+
 void GPU_framebuffer_read_depth(GPUFrameBuffer *fb, int x, int y, int w, int h, float *data)
 {
   CHECK_FRAMEBUFFER_IS_BOUND(fb);
diff --git a/source/blender/gpu/intern/gpu_shader_interface.c b/source/blender/gpu/intern/gpu_shader_interface.c
index 983c5dfc27a..f895993a27d 100644
--- a/source/blender/gpu/intern/gpu_shader_interface.c
+++ b/source/blender/gpu/intern/gpu_shader_interface.c
@@ -67,6 +67,7 @@ static const char *BuiltinUniform_name(GPUUniformBuiltin u)
       [GPU_UNIFORM_COLOR] = "color",
       [GPU_UNIFORM_BASE_INSTANCE] = "baseInstance",
       [GPU_UNIFORM_RESOURCE_CHUNK] = "resourceChunk",
+      [GPU_UNIFORM_RESOURCE_ID] = "resourceId",
 
       [GPU_UNIFORM_CUSTOM] = NULL,
       [GPU_NUM_UNIFORMS] = NULL,
diff --git a/source/blender/gpu/intern/gpu_vertex_format.c b/source/blender/gpu/intern/gpu_vertex_format.c
index 65573b71c76..16d8f8f875b 100644
--- a/source/blender/gpu/intern/gpu_vertex_format.c
+++ b/source/blender/gpu/intern/gpu_vertex_format.c
@@ -206,6 +206,47 @@ void GPU_vertformat_alias_add(GPUVertFormat *format, const char *alias)
   attr->names[attr->name_len++] = copy_attr_name(format, alias);
 }
 
+/**
+ * Makes vertex attrib from the next vertices to be accessible in the vertex shader.
+ * For an attrib named "attr" you can access the next nth vertex using "attrn".
+ * Use this function after specifying all the attribs in the format.
+ *
+ * NOTE: This does NOT work when using indexed rendering.
+ * NOTE: Only works for first attrib name. (this limitation can be changed if needed)
+ *
+ * WARNING: this function creates a lot of aliases/attribs, make sure to keep the attrib name
+ * short to avoid overflowing the namebuffer.
+ * */
+void GPU_vertformat_multiload_enable(GPUVertFormat *format, int load_count)
+{
+  /* Sanity check. Maximum can be upgraded if needed. */
+  BLI_assert(load_count > 1 && load_count < 5);
+  /* We need a packed format because of format->stride. */
+  if (!format->packed) {
+    VertexFormat_pack(format);
+  }
+
+  BLI_assert((format->name_len + 1) * load_count < GPU_VERT_FORMAT_MAX_NAMES);
+  BLI_assert(format->attr_len * load_count <= GPU_VERT_ATTR_MAX_LEN);
+  BLI_assert(format->name_offset * load_count < GPU_VERT_ATTR_NAMES_BUF_LEN);
+
+  const GPUVertAttr *attr = format->attrs;
+  int attr_len = format->attr_len;
+  for (int i = 0; i < attr_len; i++, attr++) {
+    const char *attr_name = GPU_vertformat_attr_name_get(format, attr, 0);
+    for (int j = 1; j < load_count; j++) {
+      char load_name[64];
+      BLI_snprintf(load_name, sizeof(load_name), "%s%d", attr_name, j);
+      GPUVertAttr *dst_attr = &format->attrs[format->attr_len++];
+      *dst_attr = *attr;
+
+      dst_attr->names[0] = copy_attr_name(format, load_name);
+      dst_attr->name_len = 1;
+      dst_attr->offset += format->stride * j;
+    }
+  }
+}
+
 int GPU_vertformat_attr_id_get(const GPUVertFormat *format, const char *name)
 {
   for (int i = 0; i < format->attr_len; i++) {