From ac92664aa7ed7983b7fed3c4face6af143369b52 Mon Sep 17 00:00:00 2001
From: Markus Wick <markus@selfnet.de>
Date: Wed, 14 Mar 2018 23:36:54 +0100
Subject: [PATCH] OGL: Use stream buffer for vertex data.

---
 .../renderer_opengl/gl_rasterizer.cpp           | 17 ++++++++++++-----
 src/video_core/renderer_opengl/gl_rasterizer.h  |  4 +++-
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/video_core/renderer_opengl/gl_rasterizer.cpp b/src/video_core/renderer_opengl/gl_rasterizer.cpp
index f028ea001..612540d25 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.cpp
+++ b/src/video_core/renderer_opengl/gl_rasterizer.cpp
@@ -41,12 +41,13 @@ RasterizerOpenGL::RasterizerOpenGL() : shader_dirty(true) {
     }
 
     // Generate VBO, VAO and UBO
-    vertex_buffer.Create();
+    vertex_buffer = OGLStreamBuffer::MakeBuffer(GLAD_GL_ARB_buffer_storage, GL_ARRAY_BUFFER);
+    vertex_buffer->Create(VERTEX_BUFFER_SIZE, VERTEX_BUFFER_SIZE / 2);
     vertex_array.Create();
     uniform_buffer.Create();
 
     state.draw.vertex_array = vertex_array.handle;
-    state.draw.vertex_buffer = vertex_buffer.handle;
+    state.draw.vertex_buffer = vertex_buffer->GetHandle();
     state.draw.uniform_buffer = uniform_buffer.handle;
     state.Apply();
 
@@ -434,9 +435,15 @@ void RasterizerOpenGL::DrawTriangles() {
     state.Apply();
 
     // Draw the vertex batch
-    glBufferData(GL_ARRAY_BUFFER, vertex_batch.size() * sizeof(HardwareVertex), vertex_batch.data(),
-                 GL_STREAM_DRAW);
-    glDrawArrays(GL_TRIANGLES, 0, (GLsizei)vertex_batch.size());
+    size_t max_vertices = 3 * (VERTEX_BUFFER_SIZE / (3 * sizeof(HardwareVertex)));
+    for (size_t base_vertex = 0; base_vertex < vertex_batch.size(); base_vertex += max_vertices) {
+        size_t vertices = std::min(max_vertices, vertex_batch.size() - base_vertex);
+        size_t vertex_size = vertices * sizeof(HardwareVertex);
+        auto map = vertex_buffer->Map(vertex_size, 1);
+        memcpy(map.first, vertex_batch.data() + base_vertex, vertex_size);
+        vertex_buffer->Unmap();
+        glDrawArrays(GL_TRIANGLES, map.second / sizeof(HardwareVertex), (GLsizei)vertices);
+    }
 
     // Disable scissor test
     state.scissor.enabled = false;
diff --git a/src/video_core/renderer_opengl/gl_rasterizer.h b/src/video_core/renderer_opengl/gl_rasterizer.h
index 18808b1e4..5db9b6b7a 100644
--- a/src/video_core/renderer_opengl/gl_rasterizer.h
+++ b/src/video_core/renderer_opengl/gl_rasterizer.h
@@ -27,6 +27,7 @@
 #include "video_core/renderer_opengl/gl_resource_manager.h"
 #include "video_core/renderer_opengl/gl_shader_gen.h"
 #include "video_core/renderer_opengl/gl_state.h"
+#include "video_core/renderer_opengl/gl_stream_buffer.h"
 #include "video_core/renderer_opengl/pica_to_gl.h"
 #include "video_core/shader/shader.h"
 
@@ -283,7 +284,8 @@ private:
 
     std::array<SamplerInfo, 3> texture_samplers;
     OGLVertexArray vertex_array;
-    OGLBuffer vertex_buffer;
+    static constexpr size_t VERTEX_BUFFER_SIZE = 128 * 1024 * 1024;
+    std::unique_ptr<OGLStreamBuffer> vertex_buffer;
     OGLBuffer uniform_buffer;
     OGLFramebuffer framebuffer;