Fix crash when editing shaders on Intel HD 4000.

In the Intel HD 4000 driver a shader has to be deleted in the same context in which it is created.
However, because you can't use a rendering context on different threads, to maintain the multithreaded compilation, the solution was to use the `GL_ARB_get_program_binary` and copy the binary generated for the shader and generate a shader on the main context using that binary.
This solution is limited only to Intel HD 4000 and windows.

Reviewers: fclem

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D5019

1 files changed, 6 insertions, 0 deletions

diff --git a/source/blender/gpu/GPU_shader.h b/source/blender/gpu/GPU_shader.h
index 0fe5427019a..dca66817666 100644
--- a/source/blender/gpu/GPU_shader.h
+++ b/source/blender/gpu/GPU_shader.h
@@ -58,6 +58,10 @@ GPUShader *GPU_shader_create_ex(const char *vertexcode,
                                 const char **tf_names,
                                 const int tf_count,
                                 const char *shader_name);
+GPUShader *GPU_shader_load_from_binary(const char *binary,
+                                       const int binary_format,
+                                       const int binary_len,
+                                       const char *shname);
 struct GPU_ShaderCreateFromArray_Params {
   const char **vert, **geom, **frag, **defs;
 };
@@ -95,6 +99,8 @@ void GPU_shader_uniform_int(GPUShader *shader, int location, int value);
 
 int GPU_shader_get_attribute(GPUShader *shader, const char *name);
 
+char *GPU_shader_get_binary(GPUShader *shader, int *r_binary_format, int *r_binary_len);
+
 /* Builtin/Non-generated shaders */
 typedef enum eGPUBuiltinShader {
   /* specialized drawing */