Refactor away from treating shader_info as a dictionary, and make it a proper type as ShaderWrapper. This also includes some cleanup in hos Camera renders

manimlib/camera/camera.py

@@ -12,9 +12,6 @@ from manimlib.mobject.mobject import Point
 from manimlib.utils.config_ops import digest_config
 from manimlib.utils.bezier import interpolate
 from manimlib.utils.simple_functions import fdiv
-from manimlib.utils.shaders import shader_info_to_id
-from manimlib.utils.shaders import shader_info_program_id
-from manimlib.utils.shaders import shader_info_to_program_code
 from manimlib.utils.simple_functions import clip
 from manimlib.utils.space_ops import angle_of_vector
 from manimlib.utils.space_ops import rotation_matrix_transpose_from_quaternion
@@ -168,7 +165,7 @@ class Camera(object):
         self.init_textures()
         self.init_light_source()
         self.refresh_perspective_uniforms()
-        self.static_mobjects_to_shader_info_list = {}        
+        self.static_mobject_to_render_group_list = {}
 
     def init_frame(self):
         self.frame = CameraFrame(**self.frame_config)
@@ -321,91 +318,92 @@ class Camera(object):
         self.refresh_perspective_uniforms()
         for mobject in mobjects:
             try:
-                info_list = self.static_mobjects_to_shader_info_list[id(mobject)]
+                rg_list = self.static_mobject_to_render_group_list[id(mobject)]
+                release_when_done = False
             except KeyError:
-                info_list = mobject.get_shader_info_list()
+                rg_list = map(self.get_render_group, mobject.get_shader_wrapper_list())
+                release_when_done = True
 
-            for shader_info in info_list:
-                self.render(shader_info)
+            for render_group in rg_list:
+                self.render(render_group, release_when_done)
 
-    def render(self, shader_info):
-        cached_buffers = "render_group" in shader_info
-        if cached_buffers:
-            vbo, ibo, vao, shader = shader_info["render_group"]
-        else:
-            vbo, ibo, vao, shader = self.get_render_group(shader_info)
+    def render(self, render_group, release_when_done=True):
+        shader_wrapper = render_group["shader_wrapper"]
+        shader_program = render_group["prog"]
+        self.set_shader_uniforms(shader_program, shader_wrapper)
+        self.update_depth_test(shader_wrapper)
+        render_group["vao"].render(int(shader_wrapper.render_primative))
+        if release_when_done:
+            self.release_render_group(render_group)
 
-        self.set_shader_uniforms(shader, shader_info)
-
-        if shader_info["depth_test"]:
+    def update_depth_test(self, shader_wrapper):
+        if shader_wrapper.depth_test:
             self.ctx.enable(moderngl.DEPTH_TEST)
         else:
             self.ctx.disable(moderngl.DEPTH_TEST)
 
-        vao.render(int(shader_info["render_primative"]))
-
-        if not cached_buffers:
-            self.release_gl_objects(vbo, ibo, vao)
-
-    def get_render_group(self, shader_info):
-        shader, vert_format = self.get_shader(shader_info)
-        # vbo = self.ctx.buffer(shader_info["vert_data"].tobytes())
-        vbo = self.ctx.buffer(shader_info["vert_data"])
-
-        vert_indices = shader_info["vert_indices"]
-        if vert_indices is None:
-            ibo = None
-        else:
-            ibo = self.ctx.buffer(vert_indices.astype('i4').tobytes())
-
-        vao = self.ctx.vertex_array(
-            program=shader,
-            content=[(vbo, vert_format, *shader_info["attributes"])],
-            index_buffer=ibo,
-        )
-        return (vbo, ibo, vao, shader)
-
     def set_mobjects_as_static(self, *mobjects):
-        # Create buffer and array objects holding each mobjects shader data
+        # Creates buffer and array objects holding each mobjects shader data
         for mob in mobjects:
-            info_list = mob.get_shader_info_list()
-            for info in info_list:
-                info["render_group"] = self.get_render_group(info)
-            self.static_mobjects_to_shader_info_list[id(mob)] = info_list
+            self.static_mobject_to_render_group_list[id(mob)] = [
+                self.get_render_group(sw)
+                for sw in mob.get_shader_wrapper_list()
+            ]
 
     def release_static_mobjects(self):
-        for mob, info_list in self.static_mobjects_to_shader_info_list.items():
-            for info in info_list:
-                self.release_gl_objects(*info["render_group"][:3])
-        self.static_mobjects_to_shader_info_list = {}
+        for rg_list in self.static_mobject_to_render_group_list.values():
+            for render_group in rg_list:
+                self.release_render_group(render_group)
+        self.static_mobject_to_render_group_list = {}
 
-    def release_gl_objects(self, *objs):
-        for obj in objs:
-            if obj:
-                obj.release()
+    def get_render_group(self, shader_wrapper):
+        # Data buffers
+        vbo = self.ctx.buffer(shader_wrapper.vert_data.tobytes())
+        if shader_wrapper.vert_indices is None:
+            ibo = None
+        else:
+            ibo = self.ctx.buffer(shader_wrapper.vert_indices.astype('i4').tobytes())
+
+        # Program and vertex array
+        shader_program, vert_format = self.get_shader_program(shader_wrapper)
+        vao = self.ctx.vertex_array(
+            program=shader_program,
+            content=[(vbo, vert_format, *shader_wrapper.vert_attributes)],
+            index_buffer=ibo,
+        )
+        return {
+            "vbo": vbo,
+            "ibo": ibo,
+            "vao": vao,
+            "prog": shader_program,
+            "shader_wrapper": shader_wrapper,
+        }
+
+    def release_render_group(self, render_group):
+        for key in ["vbo", "ibo", "vao"]:
+            if render_group[key] is not None:
+                render_group[key].release()
 
     # Shaders
     def init_shaders(self):
         # Initialize with the null id going to None
-        self.id_to_shader = {"": None}
+        self.id_to_shader_program = {"": None}
 
-    def get_shader(self, shader_info):
-        sid = shader_info_program_id(shader_info)
-        if sid not in self.id_to_shader:
+    def get_shader_program(self, shader_wrapper):
+        sid = shader_wrapper.get_program_id()
+        if sid not in self.id_to_shader_program:
             # Create shader program for the first time, then cache
-            # in the id_to_shader dictionary
-            program = self.ctx.program(**shader_info_to_program_code(shader_info))
-            vert_format = moderngl.detect_format(program, shader_info["attributes"])
-            self.id_to_shader[sid] = (program, vert_format)
-        program, vert_format = self.id_to_shader[sid]
-        # self.set_shader_uniforms(program, shader_info)
-        return program, vert_format
+            # in the id_to_shader_program dictionary
+            program = self.ctx.program(**shader_wrapper.get_program_code())
+            vert_format = moderngl.detect_format(program, shader_wrapper.vert_attributes)
+            self.id_to_shader_program[sid] = (program, vert_format)
+        return self.id_to_shader_program[sid]
 
-    def set_shader_uniforms(self, shader, shader_info):
-        for name, path in shader_info["texture_paths"].items():
+    def set_shader_uniforms(self, shader, shader_wrapper):
+        for name, path in shader_wrapper.texture_paths.items():
             tid = self.get_texture_id(path)
             shader[name].value = tid
-        for name, value in it.chain(shader_info["uniforms"].items(), self.perspective_uniforms.items()):
+        for name, value in it.chain(shader_wrapper.uniforms.items(), self.perspective_uniforms.items()):
             try:
                 shader[name].value = value
             except KeyError:

manimlib/mobject/mobject.py

@@ -22,10 +22,7 @@ from manimlib.utils.simple_functions import get_parameters
 from manimlib.utils.space_ops import angle_of_vector
 from manimlib.utils.space_ops import get_norm
 from manimlib.utils.space_ops import rotation_matrix_transpose
-from manimlib.utils.shaders import refresh_shader_info_id
-from manimlib.utils.shaders import get_shader_info
-from manimlib.utils.shaders import shader_info_to_id
-from manimlib.utils.shaders import is_valid_shader_info
+from manimlib.utils.shaders import ShaderWrapper
 
 
 # TODO: Explain array_attrs
@@ -217,6 +214,8 @@ class Mobject(Container):
                 setattr(copy_mobject, attr, value.copy())
             if isinstance(value, np.ndarray):
                 setattr(copy_mobject, attr, np.array(value))
+            if isinstance(value, ShaderWrapper):
+                setattr(copy_mobject, attr, value.copy())
         return copy_mobject
 
     def deepcopy(self):
@@ -235,6 +234,7 @@ class Mobject(Container):
         return self.target
 
     # Updating
+
     def init_updaters(self):
         self.time_based_updaters = []
         self.non_time_updaters = []
@@ -1194,7 +1194,7 @@ class Mobject(Container):
         def wrapper(self):
             for mob in self.get_family():
                 func(mob)
-                mob.refresh_shader_info_template_id()
+                mob.refresh_shader_wrapper_id()
         return wrapper
 
     @affects_shader_info_id
@@ -1221,8 +1221,8 @@ class Mobject(Container):
     def init_shader_data(self):
         self.shader_data = np.zeros(len(self.points), dtype=self.shader_dtype)
         self.shader_indices = None
-        self.shader_info_template = get_shader_info(
-            attributes=self.shader_data.dtype.names,
+        self.shader_wrapper = ShaderWrapper(
+            vert_data=self.shader_data,
             vert_file=self.vert_shader_file,
             geom_file=self.geom_shader_file,
             frag_file=self.frag_shader_file,
@@ -1231,8 +1231,8 @@ class Mobject(Container):
             render_primative=self.render_primative,
         )
 
-    def refresh_shader_info_template_id(self):
-        refresh_shader_info_id(self.shader_info_template)
+    def refresh_shader_wrapper_id(self):
+        self.shader_wrapper.refresh_id()
         return self
 
     def get_blank_shader_data_array(self, size, name="shader_data"):
@@ -1245,41 +1245,30 @@ class Mobject(Container):
             return new_arr
         return arr
 
-    def get_shader_info_list(self):
-        shader_infos = it.chain(
-            [self.get_shader_info()],
-            *[sm.get_shader_info_list() for sm in self.submobjects]
+    def get_shader_wrapper(self):
+        self.shader_wrapper.vert_data = self.get_shader_data()
+        self.shader_wrapper.vert_indices = self.get_shader_vert_indices()
+        self.shader_wrapper.uniforms = self.get_shader_uniforms()
+        self.shader_wrapper.depth_test = self.depth_test
+        return self.shader_wrapper
+
+    def get_shader_wrapper_list(self):
+        shader_wrappers = it.chain(
+            [self.get_shader_wrapper()],
+            *[sm.get_shader_wrapper_list() for sm in self.submobjects]
         )
-        batches = batch_by_property(shader_infos, shader_info_to_id)
+        batches = batch_by_property(shader_wrappers, lambda sw: sw.get_id())
 
         result = []
-        for info_group, sid in batches:
-            combined_info = info_group[0]
-            if not is_valid_shader_info(combined_info):
+        for wrapper_group, sid in batches:
+            shader_wrapper = wrapper_group[0]
+            if not shader_wrapper.is_valid():
                 continue
-            data_list = []
-            indices_list = []
-            num_verts = 0
-            for info in info_group:
-                data_list.append(info["vert_data"])
-                if info["vert_indices"] is not None:
-                    indices_list.append(info["vert_indices"] + num_verts)
-                    num_verts += len(info["vert_data"])
-            # Combine lists
-            combined_info["vert_data"] = np.hstack(data_list)
-            if combined_info["vert_indices"] is not None:
-                combined_info["vert_indices"] = np.hstack(indices_list)
-            if len(combined_info["vert_indices"]) > 0:
-                result.append(combined_info)
+            shader_wrapper.combine_with(*wrapper_group[1:])
+            if len(shader_wrapper.vert_data) > 0:
+                result.append(shader_wrapper)
         return result
 
-    def get_shader_info(self):
-        shader_info = dict(self.shader_info_template)
-        shader_info["vert_data"] = self.get_shader_data()
-        shader_info["vert_indices"] = self.get_shader_vert_indices()
-        shader_info["uniforms"] = self.get_shader_uniforms()
-        return shader_info
-
     def get_shader_uniforms(self):
         return {
             "is_fixed_in_frame": float(self.is_fixed_in_frame),

manimlib/mobject/types/image_mobject.py

@@ -30,24 +30,14 @@ class ImageMobject(Mobject):
 
     def init_points(self):
         self.points = np.array([UL, DL, UR, DR])
+        self.im_coords = np.array([(0, 0), (0, 1), (1, 0), (1, 1)])
         size = self.image.size
         self.set_width(2 * size[0] / size[1], stretch=True)
         self.set_height(self.height)
 
-        self.im_coords = np.array(
-            [(0, 0), (0, 1), (1, 0), (1, 1)]
-        )
-
     def init_colors(self):
         self.set_opacity(self.opacity)
 
-    def get_shader_data(self):
-        data = self.get_blank_shader_data_array(len(self.points))
-        data["point"] = self.points
-        data["im_coords"] = self.im_coords
-        data["opacity"] = self.opacity
-        return data
-
     def set_opacity(self, alpha, family=True):
         opacity = listify(alpha)
         diff = 4 - len(opacity)
@@ -67,3 +57,10 @@ class ImageMobject(Mobject):
         self.opacity = interpolate(
             mobject1.opacity, mobject2.opacity, alpha
         )
+
+    def get_shader_data(self):
+        data = self.get_blank_shader_data_array(len(self.points))
+        data["point"] = self.points
+        data["im_coords"] = self.im_coords
+        data["opacity"] = self.opacity
+        return data

manimlib/mobject/types/vectorized_mobject.py

@@ -27,8 +27,7 @@ from manimlib.utils.space_ops import earclip_triangulation
 from manimlib.utils.space_ops import get_norm
 from manimlib.utils.space_ops import get_unit_normal
 from manimlib.utils.space_ops import z_to_vector
-from manimlib.utils.shaders import refresh_shader_info_id
-from manimlib.utils.shaders import get_shader_info
+from manimlib.utils.shaders import ShaderWrapper
 
 
 class VMobject(Mobject):
@@ -882,70 +881,67 @@ class VMobject(Mobject):
     def init_shader_data(self):
         self.fill_data = np.zeros(len(self.points), dtype=self.fill_dtype)
         self.stroke_data = np.zeros(len(self.points), dtype=self.stroke_dtype)
-        self.fill_shader_info_template = get_shader_info(
-            attributes=self.fill_data.dtype.names,
+        self.fill_shader_wrapper = ShaderWrapper(
+            vert_data=self.fill_data,
+            vert_indices=np.zeros(0, dtype='i4'),
             vert_file=self.fill_vert_shader_file,
             geom_file=self.fill_geom_shader_file,
             frag_file=self.fill_frag_shader_file,
-            depth_test=self.depth_test,
             render_primative=self.render_primative,
         )
-        self.stroke_shader_info_template = get_shader_info(
-            attributes=self.stroke_data.dtype.names,
+        self.stroke_shader_wrapper = ShaderWrapper(
+            vert_data=self.stroke_data,
             vert_file=self.stroke_vert_shader_file,
             geom_file=self.stroke_geom_shader_file,
             frag_file=self.stroke_frag_shader_file,
-            depth_test=self.depth_test,
             render_primative=self.render_primative,
         )
 
-    def refresh_shader_info_template_id(self):
-        for template in [self.fill_shader_info_template, self.stroke_shader_info_template]:
-            refresh_shader_info_id(template)
+    def refresh_shader_wrapper_id(self):
+        for wrapper in [self.fill_shader_wrapper, self.stroke_shader_wrapper]:
+            wrapper.refresh_id()
         return self
 
-    def get_shader_info_list(self):
-        fill_info = dict(self.fill_shader_info_template)
-        stroke_info = dict(self.stroke_shader_info_template)
-        fill_info["uniforms"] = self.get_shader_uniforms()
-        stroke_info["uniforms"] = self.get_stroke_uniforms()
-        for info in fill_info, stroke_info:
-            info["depth_test"] = self.depth_test
+    def get_fill_shader_wrapper(self):
+        self.fill_shader_wrapper.vert_data = self.get_fill_shader_data()
+        self.fill_shader_wrapper.vert_indices = self.get_fill_shader_vert_indices()
+        self.fill_shader_wrapper.uniforms = self.get_shader_uniforms()
+        self.fill_shader_wrapper.depth_test = self.depth_test
+        return self.fill_shader_wrapper
 
+    def get_stroke_shader_wrapper(self):
+        self.stroke_shader_wrapper.vert_data = self.get_stroke_shader_data()
+        self.stroke_shader_wrapper.uniforms = self.get_stroke_uniforms()
+        self.stroke_shader_wrapper.depth_test = self.depth_test
+        return self.stroke_shader_wrapper
+
+    def get_shader_wrapper_list(self):
         # Build up data lists
-        back_stroke_data = []
-        stroke_data = []
-        fill_data = []
-        fill_vert_indices = []
-        num_fill_verts = 0  # Number of fill verts
+        fill_shader_wrappers = []
+        stroke_shader_wrappers = []
+        back_stroke_shader_wrappers = []
         for submob in self.family_members_with_points():
             if submob.has_fill():
-                data = submob.get_fill_shader_data()
-                indices = submob.get_fill_shader_vert_indices() + num_fill_verts
-                num_fill_verts += len(data)
-
-                fill_data.append(data)
-                fill_vert_indices.append(indices)
+                fill_shader_wrappers.append(submob.get_fill_shader_wrapper())
             if submob.has_stroke():
-                data = submob.get_stroke_shader_data()
+                ssw = submob.get_stroke_shader_wrapper()
                 if submob.draw_stroke_behind_fill:
-                    back_stroke_data.append(data)
+                    back_stroke_shader_wrappers.append(ssw)
                 else:
-                    stroke_data.append(data)
+                    stroke_shader_wrappers.append(ssw)
 
         # Combine data lists
+        wrapper_lists = [
+            back_stroke_shader_wrappers,
+            fill_shader_wrappers,
+            stroke_shader_wrappers
+        ]
         result = []
-        if back_stroke_data:
-            back_stroke_info = dict(stroke_info)  # Copy
-            back_stroke_info["vert_data"] = np.hstack(back_stroke_data)
-            result.append(back_stroke_info)
-        if fill_data:
-            fill_info["vert_data"] = np.hstack(fill_data)
-            fill_info["vert_indices"] = np.hstack(fill_vert_indices)
-            result.append(fill_info)
-        if stroke_data:
-            stroke_info["vert_data"] = np.hstack(stroke_data)
-            result.append(stroke_info)
+        for wlist in wrapper_lists:
+            if wlist:
+                wrapper = wlist[0]
+                wrapper.combine_with(*wlist[1:])
+                result.append(wrapper)
         return result
 
     def get_stroke_uniforms(self):
@@ -1013,7 +1009,7 @@ class VMobject(Mobject):
             return self.saved_triangulation
 
         if len(self.points) <= 1:
-            return []
+            return np.zeros(0, dtype='i4')
 
         # Rotate points such that unit normal vector is OUT
         # TODO, 99% of the time this does nothing.  Do a check for that?

manimlib/utils/shaders.py

@@ -2,6 +2,8 @@ import os
 import warnings
 import re
 import moderngl
+import numpy as np
+import copy
 
 from manimlib.constants import SHADER_DIR
 
@@ -12,111 +14,97 @@ from manimlib.constants import SHADER_DIR
 # to that shader
 
 
-# TODO, this should all be treated as an object
-# This object a shader program instead of the vert,
-# geom and frag file names, and it should cache those
-# programs in the way currently handled by Camera
-# It should replace the Camera.get_shader method with
-# its own get_shader_program method, which will take
-# in the camera's perspective_uniforms.
+class ShaderWrapper(object):
+    def __init__(self,
+                 vert_data=None,
+                 vert_indices=None,
+                 vert_file=None,
+                 geom_file=None,
+                 frag_file=None,
+                 uniforms=None,  # A dictionary mapping names of uniform variables
+                 texture_paths=None,  # A dictionary mapping names to filepaths for textures.
+                 depth_test=False,
+                 render_primative=moderngl.TRIANGLE_STRIP,
+                 ):
+        self.vert_data = vert_data
+        self.vert_indices = vert_indices
+        self.vert_attributes = vert_data.dtype.names
+        self.vert_file = vert_file
+        self.geom_file = geom_file
+        self.frag_file = frag_file
+        self.uniforms = uniforms or dict()
+        self.texture_paths = texture_paths or dict()
+        self.depth_test = depth_test
+        self.render_primative = str(render_primative)
+        self.id = self.create_id()
+        self.program_id = self.create_program_id()
 
+    def copy(self):
+        result = copy.copy(self)
+        result.vert_data = np.array(self.vert_data)
+        if result.vert_indices is not None:
+            result.vert_indices = np.array(self.vert_indices)
+        if self.uniforms:
+            result.uniforms = dict(self.uniforms)
+        if self.texture_paths:
+            result.texture_paths = dict(self.texture_paths)
+        return result
 
-SHADER_INFO_KEYS = [
-    # Vertex data for the shader (as structured array)
-    "vert_data",
-    # Index data (if applicable) for the shader
-    "index_data",
-    # List of variable names corresponding to inputs of vertex shader
-    "attributes",
-    # Filename of vetex shader
-    "vert",
-    # Filename of geometry shader, if there is one
-    "geom",
-    # Filename of fragment shader
-    "frag",
-    # A dictionary mapping names of uniform variables
-    "uniforms",
-    # A dictionary mapping names (as they show up in)
-    # the shader to filepaths for textures.
-    "texture_paths",
-    # Whether or not to apply depth test
-    "depth_test",
-    # E.g. moderngl.TRIANGLE_STRIP
-    "render_primative",
-]
+    def is_valid(self):
+        return all([
+            self.vert_data is not None,
+            self.vert_file,
+            self.frag_file,
+        ])
 
-# Exclude data
-SHADER_KEYS_FOR_ID = SHADER_INFO_KEYS[3:]
+    def get_id(self):
+        return self.id
 
+    def get_program_id(self):
+        return self.program_id
 
-def get_shader_info(vert_data=None,
-                    vert_indices=None,
-                    attributes=None,
-                    vert_file=None,
-                    geom_file=None,
-                    frag_file=None,
-                    uniforms=None,
-                    texture_paths=None,
-                    depth_test=False,
-                    render_primative=moderngl.TRIANGLE_STRIP,
-                    ):
-    result = {
-        "vert_data": vert_data,
-        "vert_indices": vert_indices,
-        "attributes": attributes,
-        "vert": vert_file,
-        "geom": geom_file,
-        "frag": frag_file,
-        "uniforms": uniforms or dict(),
-        "texture_paths": texture_paths or dict(),
-        "depth_test": depth_test,
-        "render_primative": str(render_primative),
-    }
-    result["id"] = create_shader_info_id(result)
-    result["prog_id"] = create_shader_info_program_id(result)
-    return result
+    def create_id(self):
+        # A unique id for a shader
+        return "|".join(map(str, [
+            self.vert_file,
+            self.geom_file,
+            self.frag_file,
+            self.uniforms,
+            self.texture_paths,
+            self.depth_test,
+            self.render_primative,
+        ]))
 
+    def refresh_id(self):
+        self.id = self.create_id()
 
-def is_valid_shader_info(shader_info):
-    vert_data = shader_info["vert_data"]
-    return all([
-        vert_data is not None,
-        shader_info["vert"],
-        shader_info["frag"],
-    ])
+    def create_program_id(self):
+        return "|".join(map(str, [self.vert_file, self.geom_file, self.frag_file]))
 
+    def get_program_code(self):
+        return {
+            "vertex_shader": get_shader_code_from_file(self.vert_file),
+            "geometry_shader": get_shader_code_from_file(self.geom_file),
+            "fragment_shader": get_shader_code_from_file(self.frag_file),
+        }
 
-def shader_info_to_id(shader_info):
-    return shader_info["id"]
-
-
-def shader_info_program_id(shader_info):
-    return shader_info["prog_id"]
-
-
-def create_shader_info_id(shader_info):
-    # A unique id for a shader
-    return "|".join([str(shader_info[key]) for key in SHADER_KEYS_FOR_ID])
-
-
-def refresh_shader_info_id(shader_info):
-    shader_info["id"] = create_shader_info_id(shader_info)
-
-
-def create_shader_info_program_id(shader_info):
-    return "|".join([str(shader_info[key]) for key in ["vert", "geom", "frag"]])
-
-
-def same_shader_type(info1, info2):
-    return info1["id"] == info2["id"]
-
-
-def shader_info_to_program_code(shader_info):
-    return {
-        "vertex_shader": get_shader_code_from_file(shader_info["vert"]),
-        "geometry_shader": get_shader_code_from_file(shader_info["geom"]),
-        "fragment_shader": get_shader_code_from_file(shader_info["frag"]),
-    }
+    def combine_with(self, *shader_wrappers):
+        # Assume they are of the same type
+        if len(shader_wrappers) == 0:
+            return
+        if self.vert_indices is not None:
+            num_verts = len(self.vert_data)
+            indices_list = [self.vert_indices]
+            data_list = [self.vert_data]
+            for sw in shader_wrappers:
+                indices_list.append(sw.vert_indices + num_verts)
+                data_list.append(sw.vert_data)
+                num_verts += len(sw.vert_data)
+            self.vert_indices = np.hstack(indices_list)
+            self.vert_data = np.hstack(data_list)
+        else:
+            self.vert_data = np.hstack([self.vert_data, *[sw.vert_data for sw in shader_wrappers]])
+        return self
 
 
 def get_shader_code_from_file(filename):