New upstream version 2.5.0+dfsg

1 files changed, 590 insertions, 0 deletions

diff --git a/examples/island/Island.cpp b/examples/island/Island.cpp
new file mode 100644
index 0000000..50a8f1e
--- /dev/null
+++ b/examples/island/Island.cpp
@@ -0,0 +1,590 @@
+
+////////////////////////////////////////////////////////////
+// Headers
+////////////////////////////////////////////////////////////
+#define STB_PERLIN_IMPLEMENTATION
+#include "stb_perlin.h"
+#include <SFML/Graphics.hpp>
+#include <vector>
+#include <deque>
+#include <sstream>
+#include <algorithm>
+#include <cstring>
+#include <cmath>
+
+
+namespace
+{
+    // Width and height of the application window
+    const unsigned int windowWidth = 800;
+    const unsigned int windowHeight = 600;
+
+    // Resolution of the generated terrain
+    const unsigned int resolutionX = 800;
+    const unsigned int resolutionY = 600;
+
+    // Thread pool parameters
+    const unsigned int threadCount = 4;
+    const unsigned int blockCount = 32;
+
+    struct WorkItem
+    {
+        sf::Vertex* targetBuffer;
+        unsigned int index;
+    };
+
+    std::deque<WorkItem> workQueue;
+    std::vector<sf::Thread*> threads;
+    int pendingWorkCount = 0;
+    bool workPending = true;
+    bool bufferUploadPending = false;
+    sf::Mutex workQueueMutex;
+
+    struct Setting
+    {
+        const char* name;
+        float* value;
+    };
+
+    // Terrain noise parameters
+    const int perlinOctaves = 3;
+
+    float perlinFrequency = 7.0f;
+    float perlinFrequencyBase = 4.0f;
+
+    // Terrain generation parameters
+    float heightBase = 0.0f;
+    float edgeFactor = 0.9f;
+    float edgeDropoffExponent = 1.5f;
+
+    float snowcapHeight = 0.6f;
+
+    // Terrain lighting parameters
+    float heightFactor = windowHeight / 2.0f;
+    float heightFlatten = 3.0f;
+    float lightFactor = 0.7f;
+}
+
+
+// Forward declarations of the functions we define further down
+void threadFunction();
+void generateTerrain(sf::Vertex* vertexBuffer);
+
+
+////////////////////////////////////////////////////////////
+/// Entry point of application
+///
+/// \return Application exit code
+///
+////////////////////////////////////////////////////////////
+int main()
+{
+    // Create the window of the application
+    sf::RenderWindow window(sf::VideoMode(windowWidth, windowHeight), "SFML Island",
+                            sf::Style::Titlebar | sf::Style::Close);
+    window.setVerticalSyncEnabled(true);
+
+    sf::Font font;
+    if (!font.loadFromFile("resources/sansation.ttf"))
+        return EXIT_FAILURE;
+
+    // Create all of our graphics resources
+    sf::Text hudText;
+    sf::Text statusText;
+    sf::Shader terrainShader;
+    sf::RenderStates terrainStates(&terrainShader);
+    sf::VertexBuffer terrain(sf::Triangles, sf::VertexBuffer::Static);
+
+    // Set up our text drawables
+    statusText.setFont(font);
+    statusText.setCharacterSize(28);
+    statusText.setFillColor(sf::Color::White);
+    statusText.setOutlineColor(sf::Color::Black);
+    statusText.setOutlineThickness(2.0f);
+
+    hudText.setFont(font);
+    hudText.setCharacterSize(14);
+    hudText.setFillColor(sf::Color::White);
+    hudText.setOutlineColor(sf::Color::Black);
+    hudText.setOutlineThickness(2.0f);
+    hudText.setPosition(5.0f, 5.0f);
+
+    // Staging buffer for our terrain data that we will upload to our VertexBuffer
+    std::vector<sf::Vertex> terrainStagingBuffer;
+
+    // Check whether the prerequisites are suppprted
+    bool prerequisitesSupported = sf::VertexBuffer::isAvailable() && sf::Shader::isAvailable();
+
+    // Set up our graphics resources and set the status text accordingly
+    if (!prerequisitesSupported)
+    {
+        statusText.setString("Shaders and/or Vertex Buffers Unsupported");
+    }
+    else if (!terrainShader.loadFromFile("resources/terrain.vert", "resources/terrain.frag"))
+    {
+        prerequisitesSupported = false;
+
+        statusText.setString("Failed to load shader program");
+    }
+    else
+    {
+        // Start up our thread pool
+        for (unsigned int i = 0; i < threadCount; i++)
+        {
+            threads.push_back(new sf::Thread(threadFunction));
+            threads.back()->launch();
+        }
+
+        // Create our VertexBuffer with enough space to hold all the terrain geometry
+        terrain.create(resolutionX * resolutionY * 6);
+
+        // Resize the staging buffer to be able to hold all the terrain geometry
+        terrainStagingBuffer.resize(resolutionX * resolutionY * 6);
+
+        // Generate the initial terrain
+        generateTerrain(&terrainStagingBuffer[0]);
+
+        statusText.setString("Generating Terrain...");
+    }
+
+    // Center the status text
+    statusText.setPosition((windowWidth - statusText.getLocalBounds().width) / 2.f, (windowHeight - statusText.getLocalBounds().height) / 2.f);
+
+    // Set up an array of pointers to our settings for arrow navigation
+    Setting settings[] =
+    {
+        {"perlinFrequency",     &perlinFrequency},
+        {"perlinFrequencyBase", &perlinFrequencyBase},
+        {"heightBase",          &heightBase},
+        {"edgeFactor",          &edgeFactor},
+        {"edgeDropoffExponent", &edgeDropoffExponent},
+        {"snowcapHeight",       &snowcapHeight},
+        {"heightFactor",        &heightFactor},
+        {"heightFlatten",       &heightFlatten},
+        {"lightFactor",         &lightFactor}
+    };
+
+    const int settingCount = 9;
+    int currentSetting = 0;
+
+    std::ostringstream osstr;
+    sf::Clock clock;
+
+    while (window.isOpen())
+    {
+        // Handle events
+        sf::Event event;
+        while (window.pollEvent(event))
+        {
+            // Window closed or escape key pressed: exit
+            if ((event.type == sf::Event::Closed) ||
+               ((event.type == sf::Event::KeyPressed) && (event.key.code == sf::Keyboard::Escape)))
+            {
+                window.close();
+                break;
+            }
+
+            // Arrow key pressed:
+            if (prerequisitesSupported && (event.type == sf::Event::KeyPressed))
+            {
+                switch (event.key.code)
+                {
+                    case sf::Keyboard::Return: generateTerrain(&terrainStagingBuffer[0]); break;
+                    case sf::Keyboard::Down:   currentSetting = (currentSetting + 1) % settingCount; break;
+                    case sf::Keyboard::Up:     currentSetting = (currentSetting + settingCount - 1) % settingCount; break;
+                    case sf::Keyboard::Left:   *(settings[currentSetting].value) -= 0.1f; break;
+                    case sf::Keyboard::Right:  *(settings[currentSetting].value) += 0.1f; break;
+                    default: break;
+                }
+            }
+        }
+
+        // Clear, draw graphics objects and display
+        window.clear();
+
+        window.draw(statusText);
+
+        if (prerequisitesSupported)
+        {
+            {
+                sf::Lock lock(workQueueMutex);
+
+                // Don't bother updating/drawing the VertexBuffer while terrain is being regenerated
+                if (!pendingWorkCount)
+                {
+                    // If there is new data pending to be uploaded to the VertexBuffer, do it now
+                    if (bufferUploadPending)
+                    {
+                        terrain.update(&terrainStagingBuffer[0]);
+                        bufferUploadPending = false;
+                    }
+
+                    terrainShader.setUniform("lightFactor", lightFactor);
+                    window.draw(terrain, terrainStates);
+                }
+            }
+
+            // Update and draw the HUD text
+            osstr.str("");
+            osstr << "Frame:  " << clock.restart().asMilliseconds() << "ms\n"
+                  << "perlinOctaves:  " << perlinOctaves << "\n\n"
+                  << "Use the arrow keys to change the values.\nUse the return key to regenerate the terrain.\n\n";
+
+            for (int i = 0; i < settingCount; ++i)
+                osstr << ((i == currentSetting) ? ">>  " : "       ") << settings[i].name << ":  " << *(settings[i].value) << "\n";
+
+            hudText.setString(osstr.str());
+
+            window.draw(hudText);
+        }
+
+        // Display things on screen
+        window.display();
+    }
+
+    // Shut down our thread pool
+    {
+        sf::Lock lock(workQueueMutex);
+        workPending = false;
+    }
+
+    while (!threads.empty())
+    {
+        threads.back()->wait();
+        delete threads.back();
+        threads.pop_back();
+    }
+
+    return EXIT_SUCCESS;
+}
+
+
+////////////////////////////////////////////////////////////
+/// Get the terrain elevation at the given coordinates.
+///
+////////////////////////////////////////////////////////////
+float getElevation(float x, float y)
+{
+    x = x / resolutionX - 0.5f;
+    y = y / resolutionY - 0.5f;
+
+    float elevation = 0.0f;
+
+    for (int i = 0; i < perlinOctaves; i++)
+    {
+        elevation += stb_perlin_noise3(
+            x * perlinFrequency * std::pow(perlinFrequencyBase, i),
+            y * perlinFrequency * std::pow(perlinFrequencyBase, i),
+            0, 0, 0, 0
+        ) * std::pow(perlinFrequencyBase, -i);
+    }
+
+    elevation = (elevation + 1.f) / 2.f;
+
+    float distance = 2.0f * std::sqrt(x * x + y * y);
+    elevation = (elevation + heightBase) * (1.0f - edgeFactor * std::pow(distance, edgeDropoffExponent));
+    elevation = std::min(std::max(elevation, 0.0f), 1.0f);
+
+    return elevation;
+}
+
+
+////////////////////////////////////////////////////////////
+/// Get the terrain moisture at the given coordinates.
+///
+////////////////////////////////////////////////////////////
+float getMoisture(float x, float y)
+{
+    x = x / resolutionX - 0.5f;
+    y = y / resolutionY - 0.5f;
+
+    float moisture = stb_perlin_noise3(
+        x * 4.f + 0.5f,
+        y * 4.f + 0.5f,
+        0, 0, 0, 0
+    );
+
+    return (moisture + 1.f) / 2.f;
+}
+
+
+////////////////////////////////////////////////////////////
+/// Get the lowlands terrain color for the given moisture.
+///
+////////////////////////////////////////////////////////////
+sf::Color getLowlandsTerrainColor(float moisture)
+{
+    sf::Color color =
+        moisture < 0.27f ? sf::Color(240, 240, 180) :
+        moisture < 0.3f ? sf::Color(240 - 240 * (moisture - 0.27f) / 0.03f, 240 - 40 * (moisture - 0.27f) / 0.03f, 180 - 180 * (moisture - 0.27f) / 0.03f) :
+        moisture < 0.4f ? sf::Color(0, 200, 0) :
+        moisture < 0.48f ? sf::Color(0, 200 - 40 * (moisture - 0.4f) / 0.08f, 0) :
+        moisture < 0.6f ? sf::Color(0, 160, 0) :
+        moisture < 0.7f ? sf::Color(34 * (moisture - 0.6f) / 0.1f, 160 - 60 * (moisture - 0.6f) / 0.1f, 34 * (moisture - 0.6f) / 0.1f) :
+        sf::Color(34, 100, 34);
+
+    return color;
+}
+
+
+////////////////////////////////////////////////////////////
+/// Get the highlands terrain color for the given elevation
+/// and moisture.
+///
+////////////////////////////////////////////////////////////
+sf::Color getHighlandsTerrainColor(float elevation, float moisture)
+{
+    sf::Color lowlandsColor = getLowlandsTerrainColor(moisture);
+
+    sf::Color color =
+        moisture < 0.6f ? sf::Color(112, 128, 144) :
+        sf::Color(112 + 110 * (moisture - 0.6f) / 0.4f, 128 + 56 * (moisture - 0.6f) / 0.4f, 144 - 9 * (moisture - 0.6f) / 0.4f);
+
+    float factor = std::min((elevation - 0.4f) / 0.1f, 1.f);
+
+    color.r = lowlandsColor.r * (1.f - factor) + color.r * factor;
+    color.g = lowlandsColor.g * (1.f - factor) + color.g * factor;
+    color.b = lowlandsColor.b * (1.f - factor) + color.b * factor;
+
+    return color;
+}
+
+
+////////////////////////////////////////////////////////////
+/// Get the snowcap terrain color for the given elevation
+/// and moisture.
+///
+////////////////////////////////////////////////////////////
+sf::Color getSnowcapTerrainColor(float elevation, float moisture)
+{
+    sf::Color highlandsColor = getHighlandsTerrainColor(elevation, moisture);
+
+    sf::Color color = sf::Color::White;
+
+    float factor = std::min((elevation - snowcapHeight) / 0.05f, 1.f);
+
+    color.r = highlandsColor.r * (1.f - factor) + color.r * factor;
+    color.g = highlandsColor.g * (1.f - factor) + color.g * factor;
+    color.b = highlandsColor.b * (1.f - factor) + color.b * factor;
+
+    return color;
+}
+
+
+////////////////////////////////////////////////////////////
+/// Get the terrain color for the given elevation and
+/// moisture.
+///
+////////////////////////////////////////////////////////////
+sf::Color getTerrainColor(float elevation, float moisture)
+{
+    sf::Color color =
+        elevation < 0.11f ? sf::Color(0, 0, elevation / 0.11f * 74.f + 181.0f) :
+        elevation < 0.14f ? sf::Color(std::pow((elevation - 0.11f) / 0.03f, 0.3f) * 48.f, std::pow((elevation - 0.11f) / 0.03f, 0.3f) * 48.f, 255) :
+        elevation < 0.16f ? sf::Color((elevation - 0.14f) * 128.f / 0.02f + 48.f, (elevation - 0.14f) * 128.f / 0.02f + 48.f, 127.0f + (0.16f - elevation) * 128.f / 0.02f) :
+        elevation < 0.17f ? sf::Color(240, 230, 140) :
+        elevation < 0.4f ? getLowlandsTerrainColor(moisture) :
+        elevation < snowcapHeight ? getHighlandsTerrainColor(elevation, moisture) :
+        getSnowcapTerrainColor(elevation, moisture);
+
+        return color;
+}
+
+
+////////////////////////////////////////////////////////////
+/// Compute a compressed representation of the surface
+/// normal based on the given coordinates, and the elevation
+/// of the 4 adjacent neighbours.
+///
+////////////////////////////////////////////////////////////
+sf::Vector2f computeNormal(int x, int y, float left, float right, float bottom, float top)
+{
+    sf::Vector3f deltaX(1, 0, (std::pow(right, heightFlatten) - std::pow(left, heightFlatten)) * heightFactor);
+    sf::Vector3f deltaY(0, 1, (std::pow(top, heightFlatten) - std::pow(bottom, heightFlatten)) * heightFactor);
+
+    sf::Vector3f crossProduct(
+        deltaX.y * deltaY.z - deltaX.z * deltaY.y,
+        deltaX.z * deltaY.x - deltaX.x * deltaY.z,
+        deltaX.x * deltaY.y - deltaX.y * deltaY.x
+    );
+
+    // Scale cross product to make z component 1.0f so we can drop it
+    crossProduct /= crossProduct.z;
+
+    // Return "compressed" normal
+    return sf::Vector2f(crossProduct.x, crossProduct.y);
+}
+
+
+////////////////////////////////////////////////////////////
+/// Process a terrain generation work item. Use the vector
+/// of vertices as scratch memory and upload the data to
+/// the vertex buffer when done.
+///
+////////////////////////////////////////////////////////////
+void processWorkItem(std::vector<sf::Vertex>& vertices, const WorkItem& workItem)
+{
+    unsigned int rowBlockSize = (resolutionY / blockCount) + 1;
+    unsigned int rowStart = rowBlockSize * workItem.index;
+
+    if (rowStart >= resolutionY)
+        return;
+
+    unsigned int rowEnd = std::min(rowStart + rowBlockSize, resolutionY);
+    unsigned int rowCount = rowEnd - rowStart;
+
+    const float scalingFactorX = static_cast<float>(windowWidth) / static_cast<float>(resolutionX);
+    const float scalingFactorY = static_cast<float>(windowHeight) / static_cast<float>(resolutionY);
+
+    for (unsigned int y = rowStart; y < rowEnd; y++)
+    {
+        for (int x = 0; x < resolutionX; x++)
+        {
+            int arrayIndexBase = ((y - rowStart) * resolutionX + x) * 6;
+
+            // Top left corner (first triangle)
+            if (x > 0)
+            {
+                vertices[arrayIndexBase + 0] = vertices[arrayIndexBase - 6 + 5];
+            }
+            else if (y > rowStart)
+            {
+                vertices[arrayIndexBase + 0] = vertices[arrayIndexBase - resolutionX * 6 + 1];
+            }
+            else
+            {
+                vertices[arrayIndexBase + 0].position = sf::Vector2f(x * scalingFactorX, y * scalingFactorY);
+                vertices[arrayIndexBase + 0].color = getTerrainColor(getElevation(x, y), getMoisture(x, y));
+                vertices[arrayIndexBase + 0].texCoords = computeNormal(x, y, getElevation(x - 1, y), getElevation(x + 1, y), getElevation(x, y + 1), getElevation(x, y - 1));
+            }
+
+            // Bottom left corner (first triangle)
+            if (x > 0)
+            {
+                vertices[arrayIndexBase + 1] = vertices[arrayIndexBase - 6 + 2];
+            }
+            else
+            {
+                vertices[arrayIndexBase + 1].position = sf::Vector2f(x * scalingFactorX, (y + 1) * scalingFactorY);
+                vertices[arrayIndexBase + 1].color = getTerrainColor(getElevation(x, y + 1), getMoisture(x, y + 1));
+                vertices[arrayIndexBase + 1].texCoords = computeNormal(x, y + 1, getElevation(x - 1, y + 1), getElevation(x + 1, y + 1), getElevation(x, y + 2), getElevation(x, y));
+            }
+
+            // Bottom right corner (first triangle)
+            vertices[arrayIndexBase + 2].position = sf::Vector2f((x + 1) * scalingFactorX, (y + 1) * scalingFactorY);
+            vertices[arrayIndexBase + 2].color = getTerrainColor(getElevation(x + 1, y + 1), getMoisture(x + 1, y + 1));
+            vertices[arrayIndexBase + 2].texCoords = computeNormal(x + 1, y + 1, getElevation(x, y + 1), getElevation(x + 2, y + 1), getElevation(x + 1, y + 2), getElevation(x + 1, y));
+
+            // Top left corner (second triangle)
+            vertices[arrayIndexBase + 3] = vertices[arrayIndexBase + 0];
+
+            // Bottom right corner (second triangle)
+            vertices[arrayIndexBase + 4] = vertices[arrayIndexBase + 2];
+
+            // Top right corner (second triangle)
+            if (y > rowStart)
+            {
+                vertices[arrayIndexBase + 5] = vertices[arrayIndexBase - resolutionX * 6 + 2];
+            }
+            else
+            {
+                vertices[arrayIndexBase + 5].position = sf::Vector2f((x + 1) * scalingFactorX, y * scalingFactorY);
+                vertices[arrayIndexBase + 5].color = getTerrainColor(getElevation(x + 1, y), getMoisture(x + 1, y));
+                vertices[arrayIndexBase + 5].texCoords = computeNormal(x + 1, y, getElevation(x, y), getElevation(x + 2, y), getElevation(x + 1, y + 1), getElevation(x + 1, y - 1));
+            }
+        }
+    }
+
+    // Copy the resulting geometry from our thread-local buffer into the target buffer
+    std::memcpy(workItem.targetBuffer + (resolutionX * rowStart * 6), &vertices[0], sizeof(sf::Vertex) * resolutionX * rowCount * 6);
+}
+
+
+////////////////////////////////////////////////////////////
+/// Worker thread entry point. We use a thread pool to avoid
+/// the heavy cost of constantly recreating and starting
+/// new threads whenever we need to regenerate the terrain.
+///
+////////////////////////////////////////////////////////////
+void threadFunction()
+{
+    unsigned int rowBlockSize = (resolutionY / blockCount) + 1;
+
+    std::vector<sf::Vertex> vertices(resolutionX * rowBlockSize * 6);
+
+    WorkItem workItem = {0, 0};
+
+    // Loop until the application exits
+    for (;;)
+    {
+        workItem.targetBuffer = 0;
+
+        // Check if there are new work items in the queue
+        {
+            sf::Lock lock(workQueueMutex);
+
+            if (!workPending)
+                return;
+
+            if (!workQueue.empty())
+            {
+                workItem = workQueue.front();
+                workQueue.pop_front();
+            }
+        }
+
+        // If we didn't receive a new work item, keep looping
+        if (!workItem.targetBuffer)
+        {
+            sf::sleep(sf::milliseconds(10));
+
+            continue;
+        }
+
+        processWorkItem(vertices, workItem);
+
+        {
+            sf::Lock lock(workQueueMutex);
+
+            --pendingWorkCount;
+        }
+    }
+}
+
+
+////////////////////////////////////////////////////////////
+/// Terrain generation entry point. This queues up the
+/// generation work items which the worker threads dequeue
+/// and process.
+///
+////////////////////////////////////////////////////////////
+void generateTerrain(sf::Vertex* buffer)
+{
+    bufferUploadPending = true;
+
+    // Make sure the work queue is empty before queuing new work
+    for (;;)
+    {
+        {
+            sf::Lock lock(workQueueMutex);
+
+            if (workQueue.empty())
+                break;
+        }
+
+        sf::sleep(sf::milliseconds(10));
+    }
+
+    // Queue all the new work items
+    {
+        sf::Lock lock(workQueueMutex);
+
+        for (unsigned int i = 0; i < blockCount; i++)
+        {
+            WorkItem workItem = {buffer, i};
+            workQueue.push_back(workItem);
+        }
+
+        pendingWorkCount = blockCount;
+    }
+}