public void Draw(GameTime gameTime, Camera camera)
{
try
{
// First, we need to figure out which stars
// are behind us and throw them out in front of us again
// based on how fast the camera is moving
if (!motionReady)
{
GenerateStars(camera);
vertexBuffer.SetData <VertexPointSprite>(data);
}
else
{
MoveStars(camera);
vertexBuffer.SetData <VertexPointSprite>(data);
}
{
//
// STARS
//
starEffect.Parameters["World"].SetValue(Matrix.Identity);
starEffect.Parameters["View"].SetValue(camera.View);
starEffect.Parameters["Projection"].SetValue(camera.Projection);
starEffect.Parameters["Texture"].SetValue(starTexture);
starEffect.Parameters["ViewportHeight"].SetValue(GraphicsDevice.Viewport.Height);
GraphicsDevice.SetVertexBuffer(vertexBuffer);
PointSpriteHelper.Enable();
// Set the alpha blend mode.
BlendStateHelper.BeginApply(GraphicsDevice);
BlendStateHelper.AlphaBlendEnable = true;
BlendStateHelper.SourceBlend = Blend.SourceAlpha;
BlendStateHelper.DestinationBlend = Blend.InverseSourceAlpha;
BlendStateHelper.EndApply(GraphicsDevice);
// Enable the depth buffer (so particles will not be visible through
// solid objects like the space ship), but disable depth writes
// (so particles will not obscure other particles).
GraphicsDevice.DepthStencilState = DepthStencilState.DepthRead;
for (int i = 0; i < starEffect.CurrentTechnique.Passes.Count; ++i)
{
starEffect.CurrentTechnique.Passes[i].Apply();
#if SDL2
GraphicsDevice.DrawPrimitives(PrimitiveType.PointListEXT, 0, starCount);
#endif
}
PointSpriteHelper.Disable();
GraphicsDevice.SetVertexBuffer(null);
BlendStateHelper.BeginApply(GraphicsDevice);
BlendStateHelper.AlphaBlendEnable = false;
BlendStateHelper.EndApply(GraphicsDevice);
if (GraphicsDevice.DepthStencilState.DepthBufferEnable)
{
GraphicsDevice.DepthStencilState = DepthStencilState.Default;
}
else
{
GraphicsDevice.DepthStencilState = Helpers.DepthWrite;
}
}
base.Draw(gameTime);
}
catch
{
}
}
/// <summary>
/// Draws the particle system.
/// </summary>
public override void Draw(GameTime gameTime)
{
try
{
GraphicsDevice device = GraphicsDevice;
SetCamera(Camera.View, Camera.Projection);
// Restore the vertex buffer contents if the graphics device was lost.
if (vertexBuffer.IsContentLost)
{
vertexBuffer.SetData(particles);
}
// If there are any particles waiting in the newly added queue,
// we'd better upload them to the GPU ready for drawing.
if (firstNewParticle != firstFreeParticle)
{
AddNewParticlesToVertexBuffer();
}
// If there are any active particles, draw them now!
if (firstActiveParticle != firstFreeParticle)
{
SetParticleRenderStates(device);
// Set an effect parameter describing the viewport size. This is needed
// to convert particle sizes into screen space point sprite sizes.
effectViewportHeightParameter.SetValue(device.Viewport.Height);
// Set an effect parameter describing the current time. All the vertex
// shader particle animation is keyed off this value.
effectTimeParameter.SetValue(currentTime);
// Set the particle vertex buffer and vertex declaration.
device.SetVertexBuffer(vertexBuffer);
//foreach (EffectPass pass in particleEffect.CurrentTechnique.Passes)
for (int i = 0; i < particleEffect.CurrentTechnique.Passes.Count; ++i)
{
particleEffect.CurrentTechnique.Passes[i].Apply();
#if SDL2
if (firstActiveParticle < firstFreeParticle)
{
// If the active particles are all in one consecutive range,
// we can draw them all in a single call.
device.DrawPrimitives(PrimitiveType.PointListEXT,
firstActiveParticle,
firstFreeParticle - firstActiveParticle);
}
else
{
// If the active particle range wraps past the end of the queue
// back to the start, we must split them over two draw calls.
device.DrawPrimitives(PrimitiveType.PointListEXT,
firstActiveParticle,
particles.Length - firstActiveParticle);
if (firstFreeParticle > 0)
{
device.DrawPrimitives(PrimitiveType.PointListEXT,
0,
firstFreeParticle);
}
}
#endif
}
// Reset a couple of the more unusual renderstates that we changed,
// so as not to mess up any other subsequent drawing.
PointSpriteHelper.Disable();
if (device.DepthStencilState.DepthBufferEnable)
{
device.DepthStencilState = DepthStencilState.Default;
}
else
{
device.DepthStencilState = Helpers.DepthWrite;
}
}
}
catch
{
}
drawCounter++;
}
