Workbench Simplification Refactor

This patch is (almost) a complete rewrite of workbench engine.
The features remain unchanged but the code quality is greatly improved.
Hair shading is brighter but also more correct.

This also introduce the concept of `DRWShaderLibrary` to make a simple
include system inside the GLSL files.

Differential Revision: https://developer.blender.org/D7060

1 files changed, 10 insertions, 27 deletions

diff --git a/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl b/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
index 585e48ae7ec..e957f8bbe9c 100644
--- a/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
+++ b/source/blender/draw/engines/workbench/shaders/workbench_volume_frag.glsl
@@ -1,4 +1,9 @@
 
+#pragma BLENDER_REQUIRE(common_view_lib.glsl)
+#pragma BLENDER_REQUIRE(gpu_shader_common_obinfos_lib.glsl)
+#pragma BLENDER_REQUIRE(workbench_data_lib.glsl)
+#pragma BLENDER_REQUIRE(workbench_common_lib.glsl)
+
 uniform sampler2D depthBuffer;
 
 uniform sampler3D densityTexture;
@@ -8,10 +13,9 @@ uniform sampler1D flameColorTexture;
 uniform sampler1D transferTexture;
 
 uniform int samplesLen = 256;
-uniform float noiseOfs = 0.0f;
+uniform float noiseOfs = 0.0;
 uniform float stepLength;   /* Step length in local space. */
 uniform float densityScale; /* Simple Opacity multiplicator. */
-uniform vec4 viewvecs[3];
 uniform vec3 activeColor;
 
 uniform float slicePosition;
@@ -23,34 +27,11 @@ in vec3 localPos;
 
 out vec4 fragColor;
 
-#define M_PI 3.1415926535897932 /* pi */
-
 float phase_function_isotropic()
 {
   return 1.0 / (4.0 * M_PI);
 }
 
-float get_view_z_from_depth(float depth)
-{
-  if (ProjectionMatrix[3][3] == 0.0) {
-    float d = 2.0 * depth - 1.0;
-    return -ProjectionMatrix[3][2] / (d + ProjectionMatrix[2][2]);
-  }
-  else {
-    return viewvecs[0].z + depth * viewvecs[1].z;
-  }
-}
-
-vec3 get_view_space_from_depth(vec2 uvcoords, float depth)
-{
-  if (ProjectionMatrix[3][3] == 0.0) {
-    return vec3(viewvecs[0].xy + uvcoords * viewvecs[1].xy, 1.0) * get_view_z_from_depth(depth);
-  }
-  else {
-    return viewvecs[0].xyz + vec3(uvcoords, depth) * viewvecs[1].xyz;
-  }
-}
-
 float max_v3(vec3 v)
 {
   return max(v.x, max(v.y, v.z));
@@ -209,8 +190,10 @@ void main()
 
   float depth = texelFetch(depthBuffer, ivec2(gl_FragCoord.xy), 0).r;
   float depth_end = min(depth, gl_FragCoord.z);
-  vec3 vs_ray_end = get_view_space_from_depth(screen_uv, depth_end);
-  vec3 vs_ray_ori = get_view_space_from_depth(screen_uv, 0.0);
+  vec3 vs_ray_end = view_position_from_depth(
+      screen_uv, depth_end, world_data.viewvecs, ProjectionMatrix);
+  vec3 vs_ray_ori = view_position_from_depth(
+      screen_uv, 0.0, world_data.viewvecs, ProjectionMatrix);
   vec3 vs_ray_dir = (is_persp) ? (vs_ray_end - vs_ray_ori) : vec3(0.0, 0.0, -1.0);
   vs_ray_dir /= abs(vs_ray_dir.z);