Support loading separate shader files

Author: einarf

demosys/conf/default.py

@@ -47,6 +47,7 @@
 
 PROGRAM_LOADERS = (
     'demosys.loaders.program.single.Loader',
+    'demosys.loaders.program.separate.Loader',
 )
 
 TEXTURE_DIRS = (

demosys/loaders/program/separate.py

@@ -0,0 +1,39 @@
+from demosys.loaders.base import BaseLoader
+from demosys.opengl import program
+
+
+class Loader(BaseLoader):
+    name = 'separate'
+
+    def load(self):
+
+        vs_source = self.load_shader("vertex", self.meta.vertex_shader)
+        geo_source = self.load_shader("geometry", self.meta.geometry_shader)
+        fs_source = self.load_shader("fragment", self.meta.fragment_shader)
+
+        shaders = program.ProgramShaders.from_separate(
+            self.meta,
+            vs_source,
+            geometry_source=geo_source,
+            fragment_source=fs_source,
+        )
+        prog = shaders.create()
+
+        # Wrap the program if reloadable is set
+        if self.meta.reloadable:
+            # Disable reload flag so reloads will return Program instances
+            self.meta.reloadable = False
+            # Wrap it ..
+            prog = program.ReloadableProgram(self.meta, prog)
+
+        return prog
+
+    def load_shader(self, shader_type: str, path: str):
+        """Load a single shader"""
+        if path:
+            resolved_path = self.find_program(path)
+            if not resolved_path:
+                raise ValueError("Cannot find {} shader '{}'".format(shader_type, path))
+
+            with open(resolved_path, 'r') as fd:
+                return fd.read()

demosys/resources/base.py

@@ -47,6 +47,10 @@ def loader(self):
         """
         return self._kwargs.get('loader') or self.default_loader
 
+    @loader.setter
+    def loader(self, value):
+        self._kwargs['loader'] = value
+
     @property
     def loader_cls(self) -> Type:
         """

demosys/resources/meta.py

@@ -19,7 +19,7 @@ def __init__(self, path=None, label=None, loader=None, **kwargs):
 class ProgramDescription(ResourceDescription):
     """Describes a program to load"""
     require_label = True
-    default_loader = 'single'
+    default_loader = None
     resource_type = 'programs'
 
     def __init__(self, path=None, label=None, loader=None, reloadable=False,
@@ -40,11 +40,23 @@ def __init__(self, path=None, label=None, loader=None, reloadable=False,
 
     @property
     def reloadable(self):
-        return self.kwargs.get('reloadable')
+        return self._kwargs.get('reloadable')
 
     @reloadable.setter
     def reloadable(self, value):
-        self.kwargs['reloadable'] = value
+        self._kwargs['reloadable'] = value
+
+    @property
+    def vertex_shader(self):
+        return self._kwargs.get('vertex_shader')
+
+    @property
+    def geometry_shader(self):
+        return self._kwargs.get('geometry_shader')
+
+    @property
+    def fragment_shader(self):
+        return self._kwargs.get('fragment_shader')
 
 
 class SceneDescription(ResourceDescription):
@@ -80,12 +92,12 @@ def __init__(self, path=None, label=None, loader=None, flip=True, mipmap=True, i
 
     @property
     def flip(self):
-        return self.kwargs.get('flip')
+        return self._kwargs.get('flip')
 
     @property
     def image(self):
-        return self.kwargs.get('image')
+        return self._kwargs.get('image')
 
     @property
     def mipmap(self):
-        return self.kwargs.get('mipmap')
+        return self._kwargs.get('mipmap')

demosys/resources/programs.py

@@ -2,6 +2,8 @@
 from demosys.conf import settings
 from demosys.resources.base import BaseRegistry
 from demosys.utils.module_loading import import_string
+from demosys.resources.meta import ProgramDescription
+from demosys.exceptions import ImproperlyConfigured
 
 
 class Programs(BaseRegistry):
@@ -15,5 +17,24 @@ def __init__(self):
             import_string(loader) for loader in settings.PROGRAM_LOADERS
         ]
 
+    def resolve_loader(self, meta: ProgramDescription):
+        """
+        Resolve program loader
+        """
+        if not meta.loader:
+            meta.loader = 'single' if meta.path else 'separate'
+
+        for loader_cls in self._loaders:
+            if loader_cls.name == meta.loader:
+                meta.loader_cls = loader_cls
+                break
+        else:
+            raise ImproperlyConfigured(
+                (
+                    "Program {} has no loader class registered."
+                    "Check PROGRAM_LOADERS or PROGRAM_DIRS"
+                ).format(meta.path)
+            )
+
 
 programs = Programs()

examples/cubes/dependencies.py

@@ -3,8 +3,12 @@
 effect_packages = []
 
 resources = [
-    ProgramDescription(path="cubes/cube_plain.glsl", label="plain", reloadable=True),
-    ProgramDescription(path="cubes/cube_light.glsl", label="light"),
-    ProgramDescription(path="cubes/cube_textured.glsl", label="textured"),
-    TextureDescription(path="cubes/crate.jpg", label="crate"),
+    ProgramDescription(label="plain", path="cubes/cube_plain.glsl"),
+    ProgramDescription(label="light", path="cubes/cube_light.glsl"),
+    ProgramDescription(
+        label="textured", 
+        vertex_shader="cubes/cube_textured_vs.glsl",
+        fragment_shader="cubes/cube_textured_fs.glsl",
+    ),
+    TextureDescription( label="crate", path="cubes/crate.jpg"),
 ]

examples/cubes/resources/programs/cubes/cube_textured.glsl

@@ -0,0 +1,15 @@
+#version 330
+
+out vec4 fragColor;
+uniform sampler2D wood;
+
+in vec3 normal;
+in vec2 uv;
+
+void main()
+{
+    vec3 dir = vec3(0.0, 0.0, 1.0);
+    float l = dot(dir, normalize(normal));
+    fragColor = texture(wood, uv) * min(1.0, l + 0.25);
+}
+

examples/cubes/resources/programs/cubes/cube_textured_fs.glsl

@@ -0,0 +1,18 @@
+#version 330
+
+in vec3 in_position;
+in vec3 in_normal;
+in vec2 in_uv;
+
+uniform mat4 m_proj;
+uniform mat4 m_mv;
+uniform mat3 m_normal;
+
+out vec3 normal;
+out vec2 uv;
+
+void main() {
+	gl_Position = m_proj * m_mv * vec4(in_position, 1.0);
+    normal = m_normal * in_normal;
+    uv = in_uv;
+}