[core] track VAOs and Buffers

3 files changed, 43 insertions, 26 deletions

diff --git a/src/mbgl/geometry/buffer.hpp b/src/mbgl/geometry/buffer.hpp
index d372a040bf..f1b493eb41 100644
--- a/src/mbgl/geometry/buffer.hpp
+++ b/src/mbgl/geometry/buffer.hpp
@@ -2,6 +2,7 @@
 
 #include <mbgl/gl/gl.hpp>
 #include <mbgl/gl/object_store.hpp>
+#include <mbgl/gl/gl_config.hpp>
 #include <mbgl/platform/log.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/optional.hpp>
@@ -15,11 +16,14 @@ namespace mbgl {
 
 template <
     GLsizei item_size,
-    GLenum bufferType = GL_ARRAY_BUFFER,
+    GLenum target = GL_ARRAY_BUFFER,
     GLsizei defaultLength = 8192,
     bool retainAfterUpload = false
 >
 class Buffer : private util::noncopyable {
+    static_assert(target == GL_ARRAY_BUFFER || target == GL_ELEMENT_ARRAY_BUFFER,
+                  "target must be one of GL_ARRAY_BUFFER or GL_ELEMENT_ARRAY_BUFFER");
+
 public:
     ~Buffer() {
         cleanup();
@@ -36,17 +40,24 @@ public:
     }
 
     // Transfers this buffer to the GPU and binds the buffer to the GL context.
-    void bind(gl::ObjectStore& store) {
-        if (buffer) {
-            MBGL_CHECK_ERROR(glBindBuffer(bufferType, *buffer));
-        } else {
+    void bind(gl::ObjectStore& store, gl::Config& config) {
+        const bool initialized { buffer };
+        if (!initialized) {
             buffer = store.createBuffer();
-            MBGL_CHECK_ERROR(glBindBuffer(bufferType, *buffer));
+        }
+
+        if (target == GL_ARRAY_BUFFER) {
+            config.vertexBuffer = *buffer;
+        } else {
+            config.elementBuffer = *buffer;
+        }
+
+        if (!initialized) {
             if (array == nullptr) {
                 Log::Debug(Event::OpenGL, "Buffer doesn't contain elements");
                 pos = 0;
             }
-            MBGL_CHECK_ERROR(glBufferData(bufferType, pos, array, GL_STATIC_DRAW));
+            MBGL_CHECK_ERROR(glBufferData(target, pos, array, GL_STATIC_DRAW));
             if (!retainAfterUpload) {
                 cleanup();
             }
@@ -65,9 +76,9 @@ public:
     }
 
     // Uploads the buffer to the GPU to be available when we need it.
-    void upload(gl::ObjectStore& store) {
+    void upload(gl::ObjectStore& store, gl::Config& config) {
         if (!buffer) {
-            bind(store);
+            bind(store, config);
         }
     }
 
diff --git a/src/mbgl/geometry/vao.cpp b/src/mbgl/geometry/vao.cpp
index 30f5484896..e475f43273 100644
--- a/src/mbgl/geometry/vao.cpp
+++ b/src/mbgl/geometry/vao.cpp
@@ -5,17 +5,12 @@
 
 namespace mbgl {
 
-void VertexArrayObject::Unbind() {
-    if (!gl::BindVertexArray) return;
-    MBGL_CHECK_ERROR(gl::BindVertexArray(0));
-}
-
 VertexArrayObject::VertexArrayObject() {
 }
 
 VertexArrayObject::~VertexArrayObject() = default;
 
-void VertexArrayObject::bindVertexArrayObject(gl::ObjectStore& store) {
+void VertexArrayObject::bindVertexArrayObject(gl::ObjectStore& store, gl::Config& config) {
     if (!gl::GenVertexArrays || !gl::BindVertexArray) {
         static bool reported = false;
         if (!reported) {
@@ -27,8 +22,11 @@ void VertexArrayObject::bindVertexArrayObject(gl::ObjectStore& store) {
 
     if (!vao) {
         vao = store.createVAO();
+        config.vertexBuffer.setDirty();
+        config.elementBuffer.setDirty();
     }
-    MBGL_CHECK_ERROR(gl::BindVertexArray(*vao));
+
+    config.vertexArrayObject = *vao;
 }
 
 void VertexArrayObject::verifyBinding(Shader& shader, GLuint vertexBuffer, GLuint elementsBuffer,
diff --git a/src/mbgl/geometry/vao.hpp b/src/mbgl/geometry/vao.hpp
index aa0a72ec59..5a2486fae1 100644
--- a/src/mbgl/geometry/vao.hpp
+++ b/src/mbgl/geometry/vao.hpp
@@ -3,6 +3,7 @@
 #include <mbgl/shader/shader.hpp>
 #include <mbgl/gl/gl.hpp>
 #include <mbgl/gl/object_store.hpp>
+#include <mbgl/gl/gl_config.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/optional.hpp>
 
@@ -12,16 +13,18 @@ namespace mbgl {
 
 class VertexArrayObject : public util::noncopyable {
 public:
-    static void Unbind();
-
     VertexArrayObject();
     ~VertexArrayObject();
 
     template <typename VertexBuffer>
-    void bind(Shader& shader, VertexBuffer& vertexBuffer, GLbyte* offset, gl::ObjectStore& store) {
-        bindVertexArrayObject(store);
+    void bind(Shader& shader,
+              VertexBuffer& vertexBuffer,
+              GLbyte* offset,
+              gl::ObjectStore& store,
+              gl::Config& config) {
+        bindVertexArrayObject(store, config);
         if (bound_shader == 0) {
-            vertexBuffer.bind(store);
+            vertexBuffer.bind(store, config);
             shader.bind(offset);
             if (vao) {
                 storeBinding(shader, vertexBuffer.getID(), 0, offset);
@@ -32,11 +35,16 @@ public:
     }
 
     template <typename VertexBuffer, typename ElementsBuffer>
-    void bind(Shader& shader, VertexBuffer& vertexBuffer, ElementsBuffer& elementsBuffer, GLbyte* offset, gl::ObjectStore& store) {
-        bindVertexArrayObject(store);
+    void bind(Shader& shader,
+              VertexBuffer& vertexBuffer,
+              ElementsBuffer& elementsBuffer,
+              GLbyte* offset,
+              gl::ObjectStore& store,
+              gl::Config& config) {
+        bindVertexArrayObject(store, config);
         if (bound_shader == 0) {
-            vertexBuffer.bind(store);
-            elementsBuffer.bind(store);
+            vertexBuffer.bind(store, config);
+            elementsBuffer.bind(store, config);
             shader.bind(offset);
             if (vao) {
                 storeBinding(shader, vertexBuffer.getID(), elementsBuffer.getID(), offset);
@@ -51,7 +59,7 @@ public:
     }
 
 private:
-    void bindVertexArrayObject(gl::ObjectStore&);
+    void bindVertexArrayObject(gl::ObjectStore&, gl::Config&);
     void storeBinding(Shader &shader, GLuint vertexBuffer, GLuint elementsBuffer, GLbyte *offset);
     void verifyBinding(Shader &shader, GLuint vertexBuffer, GLuint elementsBuffer, GLbyte *offset);