void MotionBlur::draw(void)
{
// Get the current view matrix (according to user input through mouse,
// gamepad, etc.)
mViewMatrix = m_transformer->getModelViewMat();
float deltaFrameTime = getFrameDeltaTime();
// Clamp dt. If the frame rate goes very low, the stretch becomes huge
// and the blurred geometry covers more of the screen which in turns
// decreases the FPS even further. The sample gets into a feedback loop
// of ever-decreasing FPS.
const float FPS_CLAMP = 1.0f / 15.0f;
if (deltaFrameTime > FPS_CLAMP)
deltaFrameTime = FPS_CLAMP;
// If the animation is pasued, we still want to show motion blur on the
// windmill sails
if (mAnimPaused)
deltaFrameTime = mLastDt;
mCurrSailAngle = mLastSailAngle + mSailSpeed * deltaFrameTime;
// houseXform puts the axle of the sails about centre-screen.
nv::matrix4f tmp;
const nv::matrix4f houseXform = nv::translation(tmp, 0.0f, -10.0f, 0.0f);
const nv::matrix4f currSailsXform = houseXform *
sailTransform(mCurrSailAngle);
const nv::matrix4f prevSailsXform = houseXform *
sailTransform(mLastSailAngle);
// Cleaning GL state
freeGLBindings();
if (!mDoMotionBlur)
renderSceneUnblurred(houseXform, currSailsXform);
else
renderSceneBlurred(houseXform, currSailsXform, prevSailsXform);
// Cleaning GL state
freeGLBindings();
// If the animation is paused, we update these values to keep the motion
// blur visible in the windmill sails
if (!mAnimPaused)
{
mLastSailAngle = mCurrSailAngle;
mLastDt = deltaFrameTime;
}
}
void GLRenderer::render(float dt) {
const float FPS_CLAMP = 1.0f / 15.0f;
if (dt > FPS_CLAMP)
dt = FPS_CLAMP;
freeGLBindings();
if (!mPaused){
drawSceneColor();
drawSceneVelocity();
drawBlurTileMax();
drawBlurNeighbourMax();
drawBlurGather();
freeGLBindings();
}
mPreviousViewMatrix = mViewMatrix;
mLastDt = dt;
}
void GLRenderer::render(float dt) {
const float FPS_CLAMP = 1.0f / 15.0f;
if (dt > FPS_CLAMP)
dt = FPS_CLAMP;
mElapsedTime += dt;
freeGLBindings();
glm::mat4 mvp = mProjectionMatrix * mViewMatrix;
glm::vec4 right = mViewMatrix[0];
glm::vec4 up = mViewMatrix[1];
mFeedbackShader->enable();
glUniform1f(mFeedbackShader->mDeltaTimeHandle, dt);
glUniform1f(mFeedbackShader->mBirthRateHandle, BIRTH_RATE);
glUniform3f(mFeedbackShader->mMousePositionHandle, mMousePosition.x, mMousePosition.y, mMousePosition.z);
glUniform1f(mFeedbackShader->mElapsedTimeHandle, mElapsedTime);
glUniform1f(mFeedbackShader->mSizeHandle, BILLBOARD_SIZE);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, mVelocityTexture);
glBindVertexArray(mVAO[(mCurrentBuffer+1)%BUFFER_COUNT]);
glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0, mVBO[mCurrentBuffer]);
glEnable(GL_RASTERIZER_DISCARD);
glBeginTransformFeedback(GL_POINTS);
glDrawArrays(GL_POINTS, 0, MAX_PARTICLES);
glEndTransformFeedback();
glDisable(GL_RASTERIZER_DISCARD);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
mBillboardShader->enable();
glUniformMatrix4fv(mBillboardShader->mModelViewProjectionHandle, 1, GL_FALSE, glm::value_ptr(mvp));
glUniform3f(mBillboardShader->mRightHandle, right.x, right.y, right.z);
glUniform3f(mBillboardShader->mUpHandle, up.x, up.y, up.z);
glUniform1f(mBillboardShader->mBillboardSizeHandle, BILLBOARD_SIZE);
glBindVertexArray(mVAO[mCurrentBuffer]);
glDrawArrays(GL_POINTS, 0, MAX_PARTICLES);
// mTestShader->enable();
// glUniformMatrix4fv(mTestShader->mMVP, 1, GL_FALSE, glm::value_ptr(mvp));
// glUniform1f(mTestShader->mElapsedTimeHandle, mElapsedTime);
// glActiveTexture(GL_TEXTURE0);
// glBindTexture(GL_TEXTURE_2D, mVelocityTexture);
// mScreenQuadModel->drawArrays();
// mTestShader->disable();
mCurrentBuffer = (mCurrentBuffer + 1) % BUFFER_COUNT;
}
