Smoke: Port display to Workbench + object mode

This does not fix the smokesim. It only port the drawing method.

The Object mode engine is in charge of rendering the velocity debugging.

Things left to do:
- Flame rendering.
- Color Ramp coloring of volume data.
- View facing slicing (for now it's only doing sampling starting from the
  volume bounds which gives a squarish look)
- Add option to enable dithering (currently on by default.

1 files changed, 31 insertions, 0 deletions

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_volume_vert.glsl b/source/blender/draw/engines/workbench/shaders/workbench_volume_vert.glsl
new file mode 100644
index 00000000000..90a22d9d02f
--- /dev/null
+++ b/source/blender/draw/engines/workbench/shaders/workbench_volume_vert.glsl
@@ -0,0 +1,31 @@
+
+uniform mat4 ModelViewProjectionMatrix;
+uniform float slicePosition;
+uniform int sliceAxis; /* -1 is no slice, 0 is X, 1 is Y, 2 is Z. */
+
+in vec3 pos;
+
+#ifdef VOLUME_SLICE
+in vec3 uvs;
+
+out vec3 localPos;
+#endif
+
+void main()
+{
+#ifdef VOLUME_SLICE
+	if (sliceAxis == 0) {
+		localPos = vec3(slicePosition * 2.0 - 1.0, pos.xy);
+	}
+	else if (sliceAxis == 1) {
+		localPos = vec3(pos.x, slicePosition * 2.0 - 1.0, pos.y);
+	}
+	else {
+		localPos = vec3(pos.xy, slicePosition * 2.0 - 1.0);
+	}
+
+	gl_Position = ModelViewProjectionMatrix * vec4(localPos, 1.0);
+#else
+	gl_Position = ModelViewProjectionMatrix * vec4(pos, 1.0);
+#endif
+}