Fix incorrect shader state after shader interface creation

Use store-current-and-restore-previous OpenGL program in the OpenGL
Shader Interface. This is a better fix for the initial error, which
additionally solves interface artifacts when opening non-default
startyp files on macOS with AMD GPU.

2 files changed, 10 insertions, 5 deletions

diff --git a/source/blender/gpu/opengl/gl_shader.cc b/source/blender/gpu/opengl/gl_shader.cc
index f6f14932de7..dafcf4dbf33 100644
--- a/source/blender/gpu/opengl/gl_shader.cc
+++ b/source/blender/gpu/opengl/gl_shader.cc
@@ -1004,11 +1004,6 @@ bool GLShader::finalize(const shader::ShaderCreateInfo *info)
   else {
     interface = new GLShaderInterface(shader_program_);
   }
-  /**
-   * WORKAROUND: Creating the shader interface changes the active program.
-   * Make sure to update the context, otherwise we might have a missing bind.
-   */
-  Context::get()->shader = this;
 
   return true;
 }
diff --git a/source/blender/gpu/opengl/gl_shader_interface.cc b/source/blender/gpu/opengl/gl_shader_interface.cc
index c9432fca561..ef97d74bf81 100644
--- a/source/blender/gpu/opengl/gl_shader_interface.cc
+++ b/source/blender/gpu/opengl/gl_shader_interface.cc
@@ -200,6 +200,9 @@ static Type gpu_type_from_gl_type(int gl_type)
 
 GLShaderInterface::GLShaderInterface(GLuint program)
 {
+  GLuint last_program;
+  glGetIntegerv(GL_CURRENT_PROGRAM, (GLint *)&last_program);
+
   /* Necessary to make #glUniform works. */
   glUseProgram(program);
 
@@ -385,6 +388,8 @@ GLShaderInterface::GLShaderInterface(GLuint program)
   // this->debug_print();
 
   this->sort_inputs();
+
+  glUseProgram(last_program);
 }
 
 GLShaderInterface::GLShaderInterface(GLuint program, const shader::ShaderCreateInfo &info)
@@ -442,6 +447,9 @@ GLShaderInterface::GLShaderInterface(GLuint program, const shader::ShaderCreateI
   uint32_t name_buffer_offset = 0;
 
   /* Necessary to make #glUniform works. TODO(fclem) Remove. */
+  GLuint last_program;
+  glGetIntegerv(GL_CURRENT_PROGRAM, (GLint *)&last_program);
+
   glUseProgram(program);
 
   /* Attributes */
@@ -552,6 +560,8 @@ GLShaderInterface::GLShaderInterface(GLuint program, const shader::ShaderCreateI
   this->sort_inputs();
 
   // this->debug_print();
+
+  glUseProgram(last_program);
 }
 
 GLShaderInterface::~GLShaderInterface()