GPU: refactor clipped drawing from DRW into GPU

Needed to fix T61196, supporting clipped back-buffer in the 3D view
which is done outside the draw module.

It was also inconvenient having DRW_shader_* versions of GPU_shader_*
API calls.

- Clipping distances are now supported as a shader configuration
  for builtin shaders.
- Add shader config argument when accessing builtin shaders.
- Move GPU_shader_create_from_arrays() from DRW to GPU.

1 files changed, 25 insertions, 0 deletions

diff --git a/source/blender/gpu/shaders/gpu_shader_cfg_world_clip_lib.glsl b/source/blender/gpu/shaders/gpu_shader_cfg_world_clip_lib.glsl
new file mode 100644
index 00000000000..6964b2a0c39
--- /dev/null
+++ b/source/blender/gpu/shaders/gpu_shader_cfg_world_clip_lib.glsl
@@ -0,0 +1,25 @@
+#ifdef USE_WORLD_CLIP_PLANES
+#if defined(GPU_VERTEX_SHADER) || defined(GPU_GEOMETRY_SHADER)
+uniform vec4 WorldClipPlanes[6];
+void world_clip_planes_calc_clip_distance(vec3 wpos)
+{
+	gl_ClipDistance[0] = dot(WorldClipPlanes[0].xyz, wpos) + WorldClipPlanes[0].w;
+	gl_ClipDistance[1] = dot(WorldClipPlanes[1].xyz, wpos) + WorldClipPlanes[1].w;
+	gl_ClipDistance[2] = dot(WorldClipPlanes[2].xyz, wpos) + WorldClipPlanes[2].w;
+	gl_ClipDistance[3] = dot(WorldClipPlanes[3].xyz, wpos) + WorldClipPlanes[3].w;
+	gl_ClipDistance[4] = dot(WorldClipPlanes[4].xyz, wpos) + WorldClipPlanes[4].w;
+	gl_ClipDistance[5] = dot(WorldClipPlanes[5].xyz, wpos) + WorldClipPlanes[5].w;
+}
+#endif
+
+#define world_clip_planes_set_clip_distance(c) \
+{ \
+	gl_ClipDistance[0] = (c)[0]; \
+	gl_ClipDistance[1] = (c)[1]; \
+	gl_ClipDistance[2] = (c)[2]; \
+	gl_ClipDistance[3] = (c)[3]; \
+	gl_ClipDistance[4] = (c)[4]; \
+	gl_ClipDistance[5] = (c)[5]; \
+}
+
+#endif