LibAccelGfx: Switch from OpenGL ES 2.0 to OpenGL 3.3

Desktop OpenGL 3.3 is currently supported by both EGL on Linux and
macOS.

Userland/Libraries/LibAccelGfx/Context.cpp

@@ -49,6 +49,12 @@ OwnPtr<Context> Context::create()
     EGLint minor;
     eglInitialize(egl_display, &major, &minor);
 
+    EGLBoolean ok = eglBindAPI(EGL_OPENGL_API);
+    if (ok == EGL_FALSE) {
+        dbgln("eglBindAPI failed");
+        VERIFY_NOT_REACHED();
+    }
+
     static EGLint const config_attributes[] = {
         EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
         EGL_BLUE_SIZE, 8,
@@ -64,10 +70,15 @@ OwnPtr<Context> Context::create()
     eglChooseConfig(egl_display, config_attributes, &egl_config, 1, &num_configs);
 
     static EGLint const context_attributes[] = {
-        EGL_CONTEXT_CLIENT_VERSION, 2,
+        EGL_CONTEXT_MAJOR_VERSION, 3,
+        EGL_CONTEXT_MINOR_VERSION, 3,
         EGL_NONE
     };
     EGLContext egl_context = eglCreateContext(egl_display, egl_config, EGL_NO_CONTEXT, context_attributes);
+    if (egl_context == EGL_FALSE) {
+        dbgln("eglCreateContext failed");
+        VERIFY_NOT_REACHED();
+    }
 
     EGLBoolean result = eglMakeCurrent(egl_display, EGL_NO_SURFACE, EGL_NO_SURFACE, egl_context);
     if (result == EGL_FALSE) {

Userland/Libraries/LibAccelGfx/Painter.cpp

@@ -43,23 +43,26 @@ Gfx::FloatRect Painter::to_clip_space(Gfx::FloatRect const& screen_rect) const
 }
 
 char const* vertex_shader_source = R"(
-attribute vec2 aVertexPosition;
+#version 330 core
+in vec2 aVertexPosition;
 void main() {
     gl_Position = vec4(aVertexPosition, 0.0, 1.0);
 }
 )";
 
 char const* solid_color_fragment_shader_source = R"(
-precision mediump float;
+#version 330 core
 uniform vec4 uColor;
+out vec4 fragColor;
 void main() {
-    gl_FragColor = uColor;
+    fragColor = uColor;
 }
 )";
 
 char const* blit_vertex_shader_source = R"(
-attribute vec4 aVertexPosition;
-varying vec2 vTextureCoord;
+#version 330 core
+in vec4 aVertexPosition;
+out vec2 vTextureCoord;
 void main() {
     gl_Position = vec4(aVertexPosition.xy, 0.0, 1.0);
     vTextureCoord = aVertexPosition.zw;
@@ -67,12 +70,13 @@ void main() {
 )";
 
 char const* blit_fragment_shader_source = R"(
-precision mediump float;
+#version 330 core
 uniform vec4 uColor;
-varying vec2 vTextureCoord;
+in vec2 vTextureCoord;
 uniform sampler2D uSampler;
+out vec4 fragColor;
 void main() {
-    gl_FragColor = texture2D(uSampler, vTextureCoord) * uColor;
+    fragColor = texture2D(uSampler, vTextureCoord) * uColor;
 }
 )";