Merge pull request #1650 from unknownbrackets/attributeless-fix

OGL: Unbind the active VAO before attributeless rendering

1 files changed, 37 insertions, 0 deletions

diff --git a/Source/Core/VideoBackends/OGL/GLUtil.cpp b/Source/Core/VideoBackends/OGL/GLUtil.cpp
index bfd6170839..dddc299fb9 100644
--- a/Source/Core/VideoBackends/OGL/GLUtil.cpp
+++ b/Source/Core/VideoBackends/OGL/GLUtil.cpp
@@ -16,6 +16,8 @@
 #include "VideoCommon/VideoConfig.h"
 
 cInterfaceBase *GLInterface;
+static GLuint attributelessVAO = 0;
+static GLuint attributelessVBO = 0;
 
 namespace OGL
 {
@@ -113,3 +115,38 @@ GLuint OpenGL_CompileProgram(const char* vertexShader, const char* fragmentShade
 	return programID;
 }
 
+void OpenGL_CreateAttributelessVAO()
+{
+	glGenVertexArrays(1, &attributelessVAO);
+	_dbg_assert_msg_(VIDEO, attributelessVAO != 0, "Attributeless VAO should have been created successfully.")
+
+	// In a compatibility context, we require a valid, bound array buffer.
+	glGenBuffers(1, &attributelessVBO);
+	_dbg_assert_msg_(VIDEO, attributelessVBO != 0, "Attributeless VBO should have been created successfully.")
+
+	// Initialize the buffer with nothing.
+	glBindBuffer(GL_ARRAY_BUFFER, attributelessVBO);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat), nullptr, GL_STATIC_DRAW);
+
+	// We must also define vertex attribute 0.
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, nullptr);
+}
+
+void OpenGL_BindAttributelessVAO()
+{
+	_dbg_assert_msg_(VIDEO, attributelessVAO != 0, "Attributeless VAO should have already been created.")
+	glBindVertexArray(attributelessVAO);
+}
+
+void OpenGL_DeleteAttributelessVAO()
+{
+	_dbg_assert_msg_(VIDEO, attributelessVAO != 0, "Attributeless VAO should have already been created.")
+	if (attributelessVAO != 0)
+	{
+		glDeleteVertexArrays(1, &attributelessVAO);
+		glDeleteBuffers(1, &attributelessVBO);
+
+		attributelessVAO = 0;
+		attributelessVBO = 0;
+	}
+}