opengl: Add OpenGlContext::glGetnTexImage()

Add glGetnTexImage() to be consistent with other robustness stuff.

src/opengl/openglcontext.cpp

@@ -334,6 +334,7 @@ void OpenGlContext::glResolveFunctions(const std::function<resolveFuncPtr(const
         // See https://www.opengl.org/registry/specs/ARB/robustness.txt
         m_glGetGraphicsResetStatus = (glGetGraphicsResetStatus_func)resolveFunction("glGetGraphicsResetStatusARB");
         m_glReadnPixels = (glReadnPixels_func)resolveFunction("glReadnPixelsARB");
+        m_glGetnTexImage = (glGetnTexImage_func)resolveFunction("glGetnTexImageARB");
         m_glGetnUniformfv = (glGetnUniformfv_func)resolveFunction("glGetnUniformfvARB");
     } else if (robustContext && haveExtRobustness) {
         // See https://www.khronos.org/registry/gles/extensions/EXT/EXT_robustness.txt
@@ -434,6 +435,15 @@ void OpenGlContext::glReadnPixels(GLint x, GLint y, GLsizei width, GLsizei heigh
     }
 }
 
+void OpenGlContext::glGetnTexImage(GLenum target, GLint level, GLenum format, GLenum type, GLsizei bufSize, void *pixels)
+{
+    if (m_glGetnTexImage) {
+        m_glGetnTexImage(target, level, format, type, bufSize, pixels);
+    } else {
+        glGetTexImage(target, level, format, type, pixels);
+    }
+}
+
 void OpenGlContext::glGetnUniformfv(GLuint program, GLint location, GLsizei bufSize, GLfloat *params)
 {
     if (m_glGetnUniformfv) {

src/opengl/openglcontext.h

@@ -31,6 +31,8 @@ class GLPlatform;
 using glGetGraphicsResetStatus_func = GLenum (*)();
 using glReadnPixels_func = void (*)(GLint x, GLint y, GLsizei width, GLsizei height,
                                     GLenum format, GLenum type, GLsizei bufSize, GLvoid *data);
+using glGetnTexImage_func = void (*)(GLenum target, GLint level, GLenum format, GLenum type,
+                                     GLsizei bufSize, void *pixels);
 using glGetnUniformfv_func = void (*)(GLuint program, GLint location, GLsizei bufSize, GLfloat *params);
 
 class KWIN_EXPORT OpenGlContext
@@ -79,6 +81,7 @@ public:
 
     GLenum checkGraphicsResetStatus();
     void glReadnPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenum format, GLenum type, GLsizei bufSize, GLvoid *data);
+    void glGetnTexImage(GLenum target, GLint level, GLenum format, GLenum type, GLsizei bufSize, void *pixels);
     void glGetnUniformfv(GLuint program, GLint location, GLsizei bufSize, GLfloat *params);
 
     void pushFramebuffer(GLFramebuffer *fbo);
@@ -124,6 +127,7 @@ protected:
     const std::unique_ptr<GLPlatform> m_glPlatform;
     glGetGraphicsResetStatus_func m_glGetGraphicsResetStatus = nullptr;
     glReadnPixels_func m_glReadnPixels = nullptr;
+    glGetnTexImage_func m_glGetnTexImage = nullptr;
     glGetnUniformfv_func m_glGetnUniformfv = nullptr;
     ShaderManager *m_shaderManager = nullptr;
     GLVertexBuffer *m_streamingBuffer = nullptr;

src/plugins/screencast/screencastutils.h

@@ -60,11 +60,7 @@ static void doGrabTexture(GLTexture *texture, QImage *target)
         context->glReadnPixels(0, 0, size.width(), size.height(), closestGLType(target->format()), GL_UNSIGNED_BYTE, target->sizeInBytes(), target->bits());
         GLFramebuffer::popFramebuffer();
     } else {
-        if (context->openglVersion() >= Version(4, 5)) {
-            glGetnTexImage(texture->target(), 0, closestGLType(target->format()), GL_UNSIGNED_BYTE, target->sizeInBytes(), target->bits());
-        } else {
-            glGetTexImage(texture->target(), 0, closestGLType(target->format()), GL_UNSIGNED_BYTE, target->bits());
-        }
+        context->glGetnTexImage(texture->target(), 0, closestGLType(target->format()), GL_UNSIGNED_BYTE, target->sizeInBytes(), target->bits());
     }
 
     if (invertNeededAndSupported) {