Uniform Buffers: try to minimize bind / unbind

Change-Id: I52c7d3fd3ff50211f2869df7e81e70ca1475d245
Reviewed-by: Andy Nichols <andy.nichols@theqtcompany.com>

2 files changed, 16 insertions, 4 deletions

diff --git a/src/render/io/uniformbuffer.cpp b/src/render/io/uniformbuffer.cpp
index 458a7ac4d..881d557df 100644
--- a/src/render/io/uniformbuffer.cpp
+++ b/src/render/io/uniformbuffer.cpp
@@ -53,9 +53,22 @@ namespace Render {
 UniformBuffer::UniformBuffer()
     : m_bufferId(~0)
     , m_isCreated(false)
+    , m_bound(false)
 {
 }
 
+void UniformBuffer::bind(GraphicsContext *ctx)
+{
+    ctx->openGLContext()->functions()->glBindBuffer(GL_UNIFORM_BUFFER, m_bufferId);
+    m_bound = true;
+}
+
+void UniformBuffer::release(GraphicsContext *ctx)
+{
+    m_bound = false;
+    ctx->openGLContext()->functions()->glBindBuffer(GL_UNIFORM_BUFFER, 0);
+}
+
 void UniformBuffer::create(GraphicsContext *ctx)
 {
     ctx->openGLContext()->functions()->glGenBuffers(1, &m_bufferId);
@@ -70,18 +83,14 @@ void UniformBuffer::destroy(GraphicsContext *ctx)
 
 void UniformBuffer::allocate(GraphicsContext *ctx, uint size, bool dynamic)
 {
-    ctx->openGLContext()->functions()->glBindBuffer(GL_UNIFORM_BUFFER, m_bufferId);
     // Either GL_STATIC_DRAW OR GL_DYNAMIC_DRAW depending on  the use case
     // TO DO: find a way to know how a buffer/QShaderData will be used to use the right usage
     ctx->openGLContext()->functions()->glBufferData(GL_UNIFORM_BUFFER, size, NULL, dynamic ? GL_DYNAMIC_DRAW : GL_STATIC_DRAW);
-    ctx->openGLContext()->functions()->glBindBuffer(GL_UNIFORM_BUFFER, 0);
 }
 
 void UniformBuffer::update(GraphicsContext *ctx, const void *data, uint size, int offset)
 {
-    ctx->openGLContext()->functions()->glBindBuffer(GL_UNIFORM_BUFFER, m_bufferId);
     ctx->openGLContext()->functions()->glBufferSubData(GL_UNIFORM_BUFFER, offset, size, data);
-    ctx->openGLContext()->functions()->glBindBuffer(GL_UNIFORM_BUFFER, 0);
 }
 
 void UniformBuffer::bindToUniformBlock(GraphicsContext *ctx, int bindingPoint)
diff --git a/src/render/io/uniformbuffer_p.h b/src/render/io/uniformbuffer_p.h
index 49db79f51..e60d30054 100644
--- a/src/render/io/uniformbuffer_p.h
+++ b/src/render/io/uniformbuffer_p.h
@@ -67,6 +67,7 @@ public:
     UniformBuffer();
 
     void bind(GraphicsContext *ctx);
+    void release(GraphicsContext *ctx);
     void create(GraphicsContext *ctx);
     void destroy(GraphicsContext *ctx);
     void allocate(GraphicsContext *ctx, uint size, bool dynamic = true);
@@ -75,10 +76,12 @@ public:
 
     inline GLuint bufferId() const { return m_bufferId; }
     inline bool isCreated() const { return m_isCreated; }
+    inline bool isBound() const { return m_bound; }
 
 private:
     GLuint m_bufferId;
     bool m_isCreated;
+    bool m_bound;
 };
 
 } // namespace Render