Add color scaling

yt_idv/scene_components/base_component.py

@@ -78,6 +78,9 @@ class SceneComponent(traitlets.HasTraits):
     cmap_log = traitlets.Bool(True)
     scale = traitlets.CFloat(1.0)
 
+    # These attributes are for when we aren't applying the colormap
+    color_scale = traitlets.CFloat(1.0)
+
     # This attribute determines whether or not this component is "active"
     active = traitlets.Bool(True)
 
@@ -354,6 +357,7 @@ def run_program(self, scene):
         with self.fb.bind(True):
             with self.program1.enable() as p:
                 scene.camera._set_uniforms(scene, p)
+                # This is for passthrough shaders.
                 self._set_uniforms(scene, p)
                 if self.render_method == "isocontours":
                     self._set_iso_uniforms(p)
@@ -367,6 +371,9 @@ def run_program(self, scene):
             with self.fb.input_bind(1, 2):
                 with self.program2.enable() as p2:
                     with scene.bind_buffer():
+                        # For passthroughs, we set this
+                        p2._set_uniform("color_factor", self.color_scale)
+                        # Now for colormaps...
                         p2._set_uniform("cmap", 0)
                         p2._set_uniform("fb_tex", 1)
                         p2._set_uniform("db_tex", 2)

yt_idv/scene_components/blocks.py

@@ -83,6 +83,15 @@ def render_gui(self, imgui, renderer, scene):
             imgui.image_button(
                 self.transfer_function.texture_name, 256, 32, frame_padding=0
             )
+            _, value = imgui.input_float(
+                "Scale Output",
+                self.color_scale,
+                format="%0.2f",
+                flags=imgui.INPUT_TEXT_ENTER_RETURNS_TRUE,
+            )
+            if _:
+                self.color_scale = value
+                changed = True
             imgui.text("Right click and drag to change")
             update = False
             data = self.transfer_function.data.astype("f4") / 255

yt_idv/shaders/known_uniforms.inc.glsl

@@ -65,3 +65,6 @@ uniform float iso_alphas[32];
 // draw outline control
 uniform float draw_boundary;
 uniform vec4 boundary_color;
+
+// factor for the color passthrough
+uniform float color_factor;

yt_idv/shaders/passthrough.frag.glsl

@@ -3,7 +3,7 @@ in vec2 UV;
 out vec4 color;
 
 void main(){
-   color = texture(fb_tex, UV);
+   color = texture(fb_tex, UV) * color_factor;
    color.a = 1.0;
    gl_FragDepth = texture(db_tex, UV).r;
 }