Implement particle drawing with draw manager

This still has a couple of issues:
* Instancing is not working when multiple particle systems use the same
primitive. Only the last particle system to be drawn with a particular
primitive shows up.

* Because of colors being passed as uniforms with static variables, the
color of the collection of the last object to be evauluated is used for
all particles being displayed.

Also, note that while this is being drawn in the clay engine, this might
be moved to the object mode later intead.

Part of T51378

1 files changed, 140 insertions, 0 deletions

diff --git a/source/blender/draw/intern/draw_cache.c b/source/blender/draw/intern/draw_cache.c
index 79b4d391fa4..db1565c8e96 100644
--- a/source/blender/draw/intern/draw_cache.c
+++ b/source/blender/draw/intern/draw_cache.c
@@ -80,6 +80,9 @@ static struct DRWShapeCache {
 	Batch *drw_camera;
 	Batch *drw_camera_tria;
 	Batch *drw_camera_focus;
+	Batch *drw_particle_cross;
+	Batch *drw_particle_circle;
+	Batch *drw_particle_axis;
 } SHC = {NULL};
 
 void DRW_shape_cache_free(void)
@@ -124,6 +127,9 @@ void DRW_shape_cache_free(void)
 	BATCH_DISCARD_ALL_SAFE(SHC.drw_camera);
 	BATCH_DISCARD_ALL_SAFE(SHC.drw_camera_tria);
 	BATCH_DISCARD_ALL_SAFE(SHC.drw_camera_focus);
+	BATCH_DISCARD_ALL_SAFE(SHC.drw_particle_cross);
+	BATCH_DISCARD_ALL_SAFE(SHC.drw_particle_circle);
+	BATCH_DISCARD_ALL_SAFE(SHC.drw_particle_axis);
 }
 
 
@@ -2206,3 +2212,137 @@ Batch *DRW_cache_particles_get_hair(ParticleSystem *psys)
 {
 	return DRW_particles_batch_cache_get_hair(psys);
 }
+
+Batch *DRW_cache_particles_get_dots(ParticleSystem *psys)
+{
+	return DRW_particles_batch_cache_get_dots(psys);
+}
+
+Batch *DRW_cache_particles_get_prim(int type)
+{
+	switch (type) {
+		case PART_DRAW_CROSS:
+			if (!SHC.drw_particle_cross) {
+				static VertexFormat format = { 0 };
+				static unsigned pos_id, axis_id;
+
+				if (format.attrib_ct == 0) {
+					pos_id = VertexFormat_add_attrib(&format, "inst_pos", COMP_F32, 3, KEEP_FLOAT);
+					axis_id = VertexFormat_add_attrib(&format, "axis", COMP_I32, 1, KEEP_INT);
+				}
+
+				VertexBuffer *vbo = VertexBuffer_create_with_format(&format);
+				VertexBuffer_allocate_data(vbo, 6);
+
+				/* X axis */
+				float co[3] = {-1.0f, 0.0f, 0.0f};
+				int axis = -1;
+				VertexBuffer_set_attrib(vbo, pos_id, 0, co);
+
+				co[0] = 1.0f;
+				VertexBuffer_set_attrib(vbo, pos_id, 1, co);
+				VertexBuffer_set_attrib(vbo, axis_id, 1, &axis);
+
+				/* Y axis */
+				co[0] = 0.0f;
+				co[1] = -1.0f;
+				VertexBuffer_set_attrib(vbo, pos_id, 2, co);
+
+				co[1] = 1.0f;
+				VertexBuffer_set_attrib(vbo, pos_id, 3, co);
+				VertexBuffer_set_attrib(vbo, axis_id, 3, &axis);
+
+				/* Z axis */
+				co[1] = 0.0f;
+				co[2] = -1.0f;
+				VertexBuffer_set_attrib(vbo, pos_id, 4, co);
+
+				co[2] = 1.0f;
+				VertexBuffer_set_attrib(vbo, pos_id, 5, co);
+				VertexBuffer_set_attrib(vbo, axis_id, 5, &axis);
+
+				SHC.drw_particle_cross = Batch_create(PRIM_LINES, vbo, NULL);
+			}
+
+			return SHC.drw_particle_cross;
+		case PART_DRAW_AXIS:
+			if (!SHC.drw_particle_axis) {
+				static VertexFormat format = { 0 };
+				static unsigned pos_id, axis_id;
+
+				if (format.attrib_ct == 0) {
+					pos_id = VertexFormat_add_attrib(&format, "inst_pos", COMP_F32, 3, KEEP_FLOAT);
+					axis_id = VertexFormat_add_attrib(&format, "axis", COMP_I32, 1, KEEP_INT);
+				}
+
+				VertexBuffer *vbo = VertexBuffer_create_with_format(&format);
+				VertexBuffer_allocate_data(vbo, 6);
+
+				/* X axis */
+				float co[3] = {0.0f, 0.0f, 0.0f};
+				int axis = 0;
+				VertexBuffer_set_attrib(vbo, pos_id, 0, co);
+
+				co[0] = 1.0f;
+				VertexBuffer_set_attrib(vbo, pos_id, 1, co);
+				VertexBuffer_set_attrib(vbo, axis_id, 1, &axis);
+
+				/* Y axis */
+				co[0] = 0.0f;
+				axis = 1;
+				VertexBuffer_set_attrib(vbo, pos_id, 2, co);
+
+				co[1] = 1.0f;
+				VertexBuffer_set_attrib(vbo, pos_id, 3, co);
+				VertexBuffer_set_attrib(vbo, axis_id, 3, &axis);
+
+				/* Z axis */
+				co[1] = 0.0f;
+				axis = 2;
+				VertexBuffer_set_attrib(vbo, pos_id, 4, co);
+
+				co[2] = 1.0f;
+				VertexBuffer_set_attrib(vbo, pos_id, 5, co);
+				VertexBuffer_set_attrib(vbo, axis_id, 5, &axis);
+
+				SHC.drw_particle_axis = Batch_create(PRIM_LINES, vbo, NULL);
+			}
+
+			return SHC.drw_particle_axis;
+		case PART_DRAW_CIRC:
+#define CIRCLE_RESOL 32
+			if (!SHC.drw_particle_circle) {
+				float v[3] = {0.0f, 0.0f, 0.0f};
+				int axis = -1;
+
+				static VertexFormat format = { 0 };
+				static unsigned pos_id, axis_id;
+
+				if (format.attrib_ct == 0) {
+					pos_id = VertexFormat_add_attrib(&format, "inst_pos", COMP_F32, 3, KEEP_FLOAT);
+					axis_id = VertexFormat_add_attrib(&format, "axis", COMP_I32, 1, KEEP_INT);
+				}
+
+				VertexBuffer *vbo = VertexBuffer_create_with_format(&format);
+				VertexBuffer_allocate_data(vbo, CIRCLE_RESOL);
+
+				for (int a = 0; a < CIRCLE_RESOL; a++) {
+					v[0] = sinf((2.0f * M_PI * a) / ((float)CIRCLE_RESOL));
+					v[1] = cosf((2.0f * M_PI * a) / ((float)CIRCLE_RESOL));
+					v[2] = 0.0f;
+					VertexBuffer_set_attrib(vbo, pos_id, a, v);
+					VertexBuffer_set_attrib(vbo, axis_id, a, &axis);
+				}
+
+				SHC.drw_particle_circle = Batch_create(PRIM_LINE_LOOP, vbo, NULL);
+			}
+
+			return SHC.drw_particle_circle;
+#undef CIRCLE_RESOL
+		default:
+			BLI_assert(false);
+			break;
+	}
+
+	return NULL;
+}