better solution: use a shared VAO and bind at the start of render()

SFTtech · Jan 1, 2025 · ec8707d · ec8707d
1 parent 62c1510
commit ec8707d
Show file tree

Hide file tree

Showing 4 changed files with 18 additions and 17 deletions.
diff --git a/libopenage/renderer/opengl/geometry.cpp b/libopenage/renderer/opengl/geometry.cpp
@@ -1,4 +1,4 @@
-// Copyright 2015-2024 the openage authors. See copying.md for legal info.
+// Copyright 2015-2025 the openage authors. See copying.md for legal info.
 
 #include "geometry.h"
 
@@ -14,10 +14,8 @@ namespace openage {
 namespace renderer {
 namespace opengl {
 
-GlGeometry::GlGeometry(const std::shared_ptr<GlContext> &context) :
-	Geometry(geometry_t::bufferless_quad) {
-	this->quad_vao = GlVertexArray(context);
-}
+GlGeometry::GlGeometry() :
+	Geometry(geometry_t::bufferless_quad) {}
 
 GlGeometry::GlGeometry(const std::shared_ptr<GlContext> &context, const resources::MeshData &mesh) :
 	Geometry(geometry_t::mesh) {
@@ -56,8 +54,7 @@ void GlGeometry::update_verts_offset(std::vector<uint8_t> const &verts, size_t o
 void GlGeometry::draw() const {
 	switch (this->get_type()) {
 	case geometry_t::bufferless_quad:
-		// Bind the empty VAO before drawing the buffer-less quad.
-		this->quad_vao->bind();
+		// a VAO must be bound before this call. This is handled by GlRenderer.
 		glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
 		break;
 

diff --git a/libopenage/renderer/opengl/geometry.h b/libopenage/renderer/opengl/geometry.h
@@ -1,4 +1,4 @@
-// Copyright 2015-2024 the openage authors. See copying.md for legal info.
+// Copyright 2015-2025 the openage authors. See copying.md for legal info.
 
 #pragma once
 
@@ -19,7 +19,7 @@ namespace opengl {
 class GlGeometry final : public Geometry {
 public:
 	/// The default constructor makes a quad.
-	GlGeometry(const std::shared_ptr<GlContext> &context);
+	GlGeometry();
 
 	/// Initialize a meshed geometry. Relatively costly, has to initialize GL buffers and copy vertex data.
 	explicit GlGeometry(const std::shared_ptr<GlContext> &context, resources::MeshData const &);
@@ -44,10 +44,6 @@ class GlGeometry final : public Geometry {
 	/// Data managing GPU memory and interpretation of mesh data.
 	/// Only present if the type is a mesh.
 	std::optional<GlMesh> mesh;
-
-	/// Empty VAO for bufferless quad drawing.
-	/// Only present if the type is bufferless_quad.
-	std::optional<GlVertexArray> quad_vao;
 };
 
 } // namespace opengl

diff --git a/libopenage/renderer/opengl/renderer.cpp b/libopenage/renderer/opengl/renderer.cpp
@@ -1,4 +1,4 @@
-// Copyright 2017-2024 the openage authors. See copying.md for legal info.
+// Copyright 2017-2025 the openage authors. See copying.md for legal info.
 
 #include "renderer.h"
 
@@ -15,6 +15,7 @@
 #include "renderer/opengl/texture.h"
 #include "renderer/opengl/uniform_buffer.h"
 #include "renderer/opengl/uniform_input.h"
+#include "renderer/opengl/vertex_array.h"
 #include "renderer/opengl/window.h"
 #include "renderer/resources/buffer_info.h"
 
@@ -26,7 +27,8 @@ GlRenderer::GlRenderer(const std::shared_ptr<GlContext> &ctx,
 	gl_context{ctx},
 	display{std::make_shared<GlRenderTarget>(ctx,
                                              viewport_size[0],
-                                             viewport_size[1])} {
+                                             viewport_size[1])},
+	shared_quad_vao(std::make_shared<GlVertexArray>(ctx)) {
 	// color used to clear the color buffers
 	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
 
@@ -63,7 +65,7 @@ std::shared_ptr<Geometry> GlRenderer::add_mesh_geometry(resources::MeshData cons
 }
 
 std::shared_ptr<Geometry> GlRenderer::add_bufferless_quad() {
-	return std::make_shared<GlGeometry>(this->gl_context);
+	return std::make_shared<GlGeometry>();
 }
 
 std::shared_ptr<RenderPass> GlRenderer::add_render_pass(std::vector<Renderable> renderables, const std::shared_ptr<RenderTarget> &target) {
@@ -169,6 +171,9 @@ void GlRenderer::render(const std::shared_ptr<RenderPass> &pass) {
 	auto gl_target = std::dynamic_pointer_cast<GlRenderTarget>(pass->get_target());
 	gl_target->bind_write();
 
+	// bind the shared quad vao for all bufferless quad geometries
+	shared_quad_vao->bind();
+
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
 	// TODO: Option for face culling

diff --git a/libopenage/renderer/opengl/renderer.h b/libopenage/renderer/opengl/renderer.h
@@ -1,4 +1,4 @@
-// Copyright 2017-2024 the openage authors. See copying.md for legal info.
+// Copyright 2017-2025 the openage authors. See copying.md for legal info.
 
 #pragma once
 
@@ -17,6 +17,7 @@ namespace opengl {
 class GlContext;
 class GlRenderPass;
 class GlRenderTarget;
+class GlVertexArray;
 class GlWindow;
 
 /// The OpenGL specialization of the rendering interface.
@@ -67,6 +68,8 @@ class GlRenderer final : public Renderer {
 
 	/// The main screen surface as a render target.
 	std::shared_ptr<GlRenderTarget> display;
+
+	std::shared_ptr<GlVertexArray> shared_quad_vao;
 };
 
 } // namespace opengl