Warp mesh fixes

- Check that the contents of the map file represent a grid with monotonically
  increasing x- and y-coordinates. This is slightly more lenient than the
  existing code that assumed uniform grid spacing without verification. A
  fully general implementation would need to use the triangles directly.

- Use an index buffer to hold the triangle coordinates, rather than
  duplicating the vertex data. This significantly reduces the amount of memory
  used, particularly when the vertex count is small enough to fit into a
  GLushort.

- As there is only one warp mesh, and changing this should be an infrequent
  operation (existing code loads one warp mesh at startup), do not use the
  resource manager machinery. This removes the possibility to use a wildcard
  extension, but only one extension was supported anyway.

- Use smart pointers to track resources rather than manual new/delete.

Author: ajtribick

src/celengine/CMakeLists.txt

@@ -54,8 +54,6 @@ set(CELENGINE_SOURCES
   location.h
   lodspheremesh.cpp
   lodspheremesh.h
-  mapmanager.cpp
-  mapmanager.h
   marker.cpp
   marker.h
   meshmanager.cpp
@@ -155,6 +153,8 @@ set(CELENGINE_SOURCES
   virtualtex.h
   visibleregion.cpp
   visibleregion.h
+  warpmesh.cpp
+  warpmesh.h
 )
 
 add_library(celengine OBJECT ${CELENGINE_SOURCES})

src/celengine/mapmanager.cpp

@@ -13,7 +13,7 @@
 #include "framebuffer.h"
 #include "render.h"
 #include "shadermanager.h"
-#include "mapmanager.h"
+#include "warpmesh.h"
 
 namespace gl = celestia::gl;
 namespace util = celestia::util;
@@ -70,7 +70,7 @@ void PassthroughViewportEffect::initialize()
         return;
     initialized = true;
 
-    static std::array quadVertices = {
+    static constexpr std::array quadVertices = {
         // positions   // texCoords
         -1.0f,  1.0f,  0.0f, 1.0f,
         -1.0f, -1.0f,  0.0f, 0.0f,
@@ -103,12 +103,13 @@ void PassthroughViewportEffect::initialize()
         2 * sizeof(float));
 }
 
-WarpMeshViewportEffect::WarpMeshViewportEffect(WarpMesh *mesh) :
-    ViewportEffect(),
-    mesh(mesh)
+WarpMeshViewportEffect::WarpMeshViewportEffect(std::unique_ptr<WarpMesh>&& _mesh) :
+    mesh(std::move(_mesh))
 {
 }
 
+WarpMeshViewportEffect::~WarpMeshViewportEffect() = default;
+
 bool WarpMeshViewportEffect::prerender(Renderer* renderer, FramebufferObject* fbo)
 {
     if (mesh == nullptr)
@@ -143,35 +144,9 @@ void WarpMeshViewportEffect::initialize()
     initialized = true;
 
     vo = gl::VertexObject();
-    bo = gl::Buffer();
-
-    bo.setData(mesh->scopedDataForRendering(), gl::Buffer::BufferUsage::StaticDraw);
+    bo = gl::Buffer(gl::Buffer::TargetHint::Array);
 
-    vo.setCount(mesh->count());
-    vo.addVertexBuffer(
-        bo,
-        CelestiaGLProgram::VertexCoordAttributeIndex,
-        2,
-        gl::VertexObject::DataType::Float,
-        false,
-        5 * sizeof(float),
-        0);
-    vo.addVertexBuffer(
-        bo,
-        CelestiaGLProgram::TextureCoord0AttributeIndex,
-        2,
-        gl::VertexObject::DataType::Float,
-        false,
-        5 * sizeof(float),
-        2 * sizeof(float));
-    vo.addVertexBuffer(
-        bo,
-        CelestiaGLProgram::IntensityAttributeIndex,
-        1,
-        gl::VertexObject::DataType::Float,
-        false,
-        5 * sizeof(float),
-        4 * sizeof(float));
+    mesh->setUpVertexObject(vo, bo);
 }
 
 bool WarpMeshViewportEffect::distortXY(float &x, float &y)
@@ -181,7 +156,7 @@ bool WarpMeshViewportEffect::distortXY(float &x, float &y)
 
     float u;
     float v;
-    if (!mesh->mapVertex(x * 2.0f, y * 2.0f, &u, &v))
+    if (!mesh->mapVertex(x * 2.0f, y * 2.0f, u, v))
         return false;
 
     x = u / 2.0f;

src/celengine/mapmanager.h

@@ -10,6 +10,8 @@
 
 #pragma once
 
+#include <memory>
+
 #include <celrender/gl/buffer.h>
 #include <celrender/gl/vertexobject.h>
 
@@ -52,8 +54,8 @@ class PassthroughViewportEffect : public ViewportEffect
 class WarpMeshViewportEffect : public ViewportEffect
 {
 public:
-    WarpMeshViewportEffect(WarpMesh *mesh);
-    ~WarpMeshViewportEffect() override = default;
+    explicit WarpMeshViewportEffect(std::unique_ptr<WarpMesh>&& mesh);
+    ~WarpMeshViewportEffect() override;
 
     bool prerender(Renderer*, FramebufferObject* fbo) override;
     bool render(Renderer*, FramebufferObject*, int width, int height) override;
@@ -63,7 +65,7 @@ class WarpMeshViewportEffect : public ViewportEffect
     celestia::gl::VertexObject vo{ celestia::util::NoCreateT{} };
     celestia::gl::Buffer bo{ celestia::util::NoCreateT{} };
 
-    WarpMesh *mesh;
+    std::unique_ptr<WarpMesh> mesh;
 
     void initialize();