LibGL: Implement glAttachShader

Userland/Libraries/LibGL/Shaders/Program.cpp

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <LibGL/GL/gl.h>
 #include <LibGL/Shaders/Program.h>
 
 namespace GL {
@@ -13,9 +14,36 @@ NonnullRefPtr<Program> Program::create()
     return adopt_ref(*new Program());
 }
 
-ErrorOr<void> Program::attach_shader(Shader&)
+bool Program::is_shader_attached(Shader const& shader) const
 {
-    TODO();
+    switch (shader.type()) {
+    case GL_VERTEX_SHADER:
+        return m_vertex_shaders.contains_slow(shader);
+    case GL_FRAGMENT_SHADER:
+        return m_fragment_shaders.contains_slow(shader);
+    default:
+        VERIFY_NOT_REACHED();
+    }
+}
+
+ErrorOr<void> Program::attach_shader(Shader& shader)
+{
+    if (is_shader_attached(shader))
+        return Error::from_string_literal("Trying to attach a shader that is already attached");
+
+    switch (shader.type()) {
+    case GL_VERTEX_SHADER:
+        TRY(m_vertex_shaders.try_append(shader));
+        break;
+
+    case GL_FRAGMENT_SHADER:
+        TRY(m_fragment_shaders.try_append(shader));
+        break;
+
+    default:
+        VERIFY_NOT_REACHED();
+    }
+
     return {};
 }
 

Userland/Libraries/LibGL/Shaders/Program.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <AK/Error.h>
 #include <AK/NonnullRefPtr.h>
 #include <AK/RefCounted.h>
 #include <AK/Vector.h>
@@ -17,6 +18,7 @@ class Program final : public RefCounted<Program> {
 public:
     static NonnullRefPtr<Program> create();
 
+    bool is_shader_attached(Shader const&) const;
     ErrorOr<void> attach_shader(Shader&);
     ErrorOr<void> link();
 

Userland/Libraries/LibGL/Shaders/Shader.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/Error.h>
+#include <AK/NonnullRefPtr.h>
 #include <AK/RefCounted.h>
 #include <AK/RefPtr.h>
 #include <AK/String.h>