From 9e959441954412746af577a3d57f9d2e174402dd Mon Sep 17 00:00:00 2001
From: samcake <samuel.gateau@gmail.com>
Date: Wed, 8 Feb 2017 11:36:34 -0800
Subject: [PATCH] clean the usage of glCopyImageSubData and provide a fall back
 for 4.2)

---
 .../src/gpu/gl45/GL45BackendTexture.cpp       | 38 +++++--------------
 1 file changed, 10 insertions(+), 28 deletions(-)

diff --git a/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp b/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp
index 8ba90f447e..6948a045a2 100644
--- a/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp
+++ b/libraries/gpu-gl/src/gpu/gl45/GL45BackendTexture.cpp
@@ -439,35 +439,17 @@ void GL45Texture::stripToMip(uint16_t newMinMip) {
         {
             PROFILE_RANGE(render_gpu_gl, "Blit"); 
             // Preferred path only available in 4.3
-            if (GLEW_VERSION_4_3) {
-                for (uint16 targetMip = _minMip; targetMip <= _maxMip; ++targetMip) {
-                    uint16 sourceMip = targetMip + mipDelta;
-                    Vec3u mipDimensions = _gpuObject.evalMipDimensions(targetMip + _mipOffset);
-                    for (GLenum target : getFaceTargets(_target)) {
-                        glCopyImageSubData(
-                            oldId, target, sourceMip, 0, 0, 0,
-                            _id, target, targetMip, 0, 0, 0,
-                            mipDimensions.x, mipDimensions.y, 1
-                            );
-                        (void)CHECK_GL_ERROR();
-                    }
+            for (uint16 targetMip = _minMip; targetMip <= _maxMip; ++targetMip) {
+                uint16 sourceMip = targetMip + mipDelta;
+                Vec3u mipDimensions = _gpuObject.evalMipDimensions(targetMip + _mipOffset);
+                for (GLenum target : getFaceTargets(_target)) {
+                    glCopyImageSubData(
+                        oldId, target, sourceMip, 0, 0, 0,
+                        _id, target, targetMip, 0, 0, 0,
+                        mipDimensions.x, mipDimensions.y, 1
+                        );
+                    (void)CHECK_GL_ERROR();
                 }
-            } else {
-                GLuint fbo { 0 };
-                glCreateFramebuffers(1, &fbo);
-                glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
-                for (uint16 targetMip = _minMip; targetMip <= _maxMip; ++targetMip) {
-                    uint16 sourceMip = targetMip + mipDelta;
-                    Vec3u mipDimensions = _gpuObject.evalMipDimensions(targetMip + _mipOffset);
-                    for (GLenum target : getFaceTargets(_target)) {
-                        glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, target, oldId, sourceMip);
-                        (void)CHECK_GL_ERROR();
-                        glCopyTextureSubImage2D(_id, targetMip, 0, 0, 0, 0, mipDimensions.x, mipDimensions.y);
-                        (void)CHECK_GL_ERROR();
-                    }
-                }
-                glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
-                glDeleteFramebuffers(1, &fbo);
             }
 
             glDeleteTextures(1, &oldId);