GamePlay/samples/browser/src/TriangleSample.cpp

#include "TriangleSample.h"
#include "SamplesGame.h"

#if defined(ADD_SAMPLE)
    ADD_SAMPLE("Graphics", "Draw Triangle", TriangleSample, 1);
#endif

/**
 * Creates a triangle mesh with vertex colors.
 */
static Mesh* createTriangleMesh()
{
    // Calculate the vertices of the equilateral triangle.
    float a = 0.5f;     // length of the side
    Vector2 p1(0.0f,       a / sqrtf(3.0f));
    Vector2 p2(-a / 2.0f, -a / (2.0f * sqrtf(3.0f)));
    Vector2 p3( a / 2.0f, -a / (2.0f * sqrtf(3.0f)));

    // Create 3 vertices. Each vertex has position (x, y, z) and color (red, green, blue)
    float vertices[] =
    {
        p1.x, p1.y, 0.0f,     1.0f, 0.0f, 0.0f,
        p2.x, p2.y, 0.0f,     0.0f, 1.0f, 0.0f,
        p3.x, p3.y, 0.0f,     0.0f, 0.0f, 1.0f,
    };
    unsigned int vertexCount = 3;
    VertexFormat::Element elements[] =
    {
        VertexFormat::Element(VertexFormat::POSITION, 3),
        VertexFormat::Element(VertexFormat::COLOR, 3)
    };
    Mesh* mesh = Mesh::createMesh(VertexFormat(elements, 2), vertexCount, false);
    if (mesh == NULL)
    {
        GP_ERROR("Failed to create mesh.");
        return NULL;
    }
    mesh->setPrimitiveType(Mesh::TRIANGLES);
    mesh->setVertexData(vertices, 0, vertexCount);
    return mesh;
}

TriangleSample::TriangleSample()
    : _font(NULL), _model(NULL), _spinDirection(-1.0f)
{
    
}

void TriangleSample::initialize()
{
    // Create the font for drawing the framerate.
    _font = Font::create("res/common/arial.gpb");

    // Create an orthographic projection matrix.
    float width = getWidth() / (float)getHeight();
    float height = 1.0f;
    Matrix::createOrthographic(width, height, -1.0f, 1.0f, &_worldViewProjectionMatrix);

    // Create the triangle mesh.
    Mesh* mesh = createTriangleMesh();

    // Create a model for the triangle mesh. A model is an instance of a Mesh that can be drawn with a specified material.
    _model = Model::create(mesh);
    SAFE_RELEASE(mesh);

    // Create a material from the built-in "colored-unlit" vertex and fragment shaders.
    // This sample doesn't use lighting so the unlit shader is used.
    // This sample uses vertex color so VERTEX_COLOR is defined. Look at the shader source files to see the supported defines.
    _model->setMaterial("res/shaders/colored.vert", "res/shaders/colored.frag", "VERTEX_COLOR");
}

void TriangleSample::finalize()
{
    // Model and font are reference counted and should be released before closing this sample.
    SAFE_RELEASE(_model);
    SAFE_RELEASE(_font);
}

void TriangleSample::update(float elapsedTime)
{
    // Update the rotation of the triangle. The speed is 180 degrees per second.
    _worldViewProjectionMatrix.rotateZ( _spinDirection * MATH_PI * elapsedTime * 0.001f);
}

void TriangleSample::render(float elapsedTime)
{
    // Clear the color and depth buffers
    clear(CLEAR_COLOR_DEPTH, Vector4::zero(), 1.0f, 0);
    
    // Bind the view projection matrix to the model's parameter. This will transform the vertices when the model is drawn.
    _model->getMaterial()->getParameter("u_worldViewProjectionMatrix")->setValue(_worldViewProjectionMatrix);
    _model->draw();

    drawFrameRate(_font, Vector4(0, 0.5f, 1, 1), 5, 1, getFrameRate());
}

void TriangleSample::touchEvent(Touch::TouchEvent evt, int x, int y, unsigned int contactIndex)
{
    switch (evt)
    {
    case Touch::TOUCH_PRESS:
        if (x < 75 && y < 50)
        {
            // Toggle Vsync if the user touches the top left corner
            setVsync(!isVsync());
        }
        else
        {
            // Reverse the spin direction if the user touches the screen.
            _spinDirection *= -1.0f;
        }
        break;
    case Touch::TOUCH_RELEASE:
        break;
    case Touch::TOUCH_MOVE:
        break;
    };
}