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#include "voronoisplat.h"
#include <algorithm>
#include <QQuickWindow>
#include <QOpenGLFunctions>
#include <QOpenGLShaderProgram>
#include <QOpenGLVertexArrayObject>
#include "colormap.h"
#include "scale.h"
#include "scatterplot.h"
#include "skelft.h"
static const float RAD_BLUR = 5.0f;
static int nextPow2(int n)
{
// TODO: check for overflows
n--;
for (int shift = 1; ((n + 1) & n); shift <<= 1) {
n |= n >> shift;
}
return n + 1;
}
VoronoiSplat::VoronoiSplat(QQuickItem *parent)
: QQuickFramebufferObject(parent)
, m_cmap(3*Colormap::SAMPLES)
{
setTextureFollowsItemSize(false);
}
void VoronoiSplat::setSites(const arma::mat &points)
{
if (points.n_rows < 1 || points.n_cols != 2
|| (m_values.size() != 0 && points.n_rows != m_values.size())) {
return;
}
// Copy 'points' to internal data structure(s)
double minX = points.col(0).min();
double maxX = points.col(0).max();
double minY = points.col(1).min();
double maxY = points.col(1).max();
// Coords are packed into 'm_sites' as [ x1, y1, x2, y2, ... ]
m_sites.resize(2*points.n_rows);
LinearScale<float> sx(minX, maxX, Scatterplot::PADDING, width() - Scatterplot::PADDING);
const double *col = points.colptr(0);
for (unsigned i = 0; i < points.n_rows; i++) {
m_sites[2*i] = sx(col[i]);
}
col = points.colptr(1);
LinearScale<float> sy(minY, maxY, height() - Scatterplot::PADDING, Scatterplot::PADDING);
for (unsigned i = 0; i < points.n_rows; i++) {
m_sites[2*i + 1] = sy(col[i]);
}
setSitesChanged(true);
update();
}
void VoronoiSplat::setValues(const arma::vec &values)
{
if (values.n_elem == 0
|| (m_sites.size() != 0 && values.n_elem != m_sites.size() / 2)) {
return;
}
m_values.resize(values.n_elem);
LinearScale<float> scale(values.min(), values.max(), 0, 1.0f);
std::transform(values.begin(), values.end(), m_values.begin(), scale);
emit valuesChanged(values);
setValuesChanged(true);
update();
}
void VoronoiSplat::setColorScale(const ColorScale &scale)
{
scale.sample(Colormap::SAMPLES, m_cmap.begin());
emit colorScaleChanged(scale);
setColorScaleChanged(true);
update();
}
// ----------------------------------------------------------------------------
class VoronoiSplatRenderer
: public QQuickFramebufferObject::Renderer
{
public:
// 'size' must be square (and power of 2)
VoronoiSplatRenderer();
virtual ~VoronoiSplatRenderer();
protected:
QOpenGLFramebufferObject *createFramebufferObject(const QSize &size);
void render();
void synchronize(QQuickFramebufferObject *item);
private:
void setupShaders();
void setupVAOs();
void setupTextures();
void resizeTextures();
void updateSites();
void updateValues();
void updateColorScale();
void computeDT();
QSize m_size;
const std::vector<float> *m_sites, *m_values, *m_cmap;
QQuickWindow *m_window; // used to reset OpenGL state (as per docs)
QOpenGLFunctions gl;
QOpenGLShaderProgram *m_program1, *m_program2;
GLuint m_FBO;
GLuint m_VBOs[3];
GLuint m_textures[2], m_colormapTex;
QOpenGLVertexArrayObject m_sitesVAO, m_2ndPassVAO;
bool m_sitesChanged, m_valuesChanged, m_colorScaleChanged;
};
QQuickFramebufferObject::Renderer *VoronoiSplat::createRenderer() const
{
return new VoronoiSplatRenderer;
}
VoronoiSplatRenderer::VoronoiSplatRenderer()
: gl(QOpenGLContext::currentContext())
{
gl.glGenFramebuffers(1, &m_FBO);
setupShaders();
setupVAOs();
setupTextures();
}
void VoronoiSplatRenderer::setupShaders()
{
m_program1 = new QOpenGLShaderProgram;
m_program1->addShaderFromSourceCode(QOpenGLShader::Vertex,
R"EOF(#version 440
uniform float rad_blur;
uniform float rad_max;
uniform float fb_size;
in vec2 vert;
in float scalar;
out float value;
void main() {
gl_PointSize = (rad_max + rad_blur) * 2.0;
gl_Position = vec4(2.0 * vert / fb_size - 1.0, 0, 1.0);
value = scalar;
}
)EOF");
m_program1->addShaderFromSourceCode(QOpenGLShader::Fragment,
R"EOF(#version 440
uniform float rad_blur;
uniform float rad_max;
uniform sampler2D siteDT;
in float value;
layout (location = 0) out vec4 fragColor;
void main() {
float dt = texelFetch(siteDT, ivec2(gl_FragCoord.xy), 0).r;
if (dt > rad_max)
discard;
else {
float r = distance(gl_PointCoord, vec2(0.5, 0.5)) * (rad_max + rad_blur) * 2.0;
float r2 = r * r;
float rad = dt + rad_blur;
float rad2 = rad * rad;
if (r2 > rad2)
discard;
else {
float w = exp(-5.0 * r2 / rad2);
fragColor = vec4(w * value, w, 0.0, 0.0);
}
}
}
)EOF");
m_program1->link();
m_program2 = new QOpenGLShaderProgram;
m_program2->addShaderFromSourceCode(QOpenGLShader::Vertex,
R"EOF(#version 440
in vec2 vert;
void main() {
gl_Position = vec4(vert, 0, 1);
}
)EOF");
m_program2->addShaderFromSourceCode(QOpenGLShader::Fragment,
R"EOF(
#version 440
uniform sampler2D siteDT;
uniform sampler2D accumTex;
uniform sampler2D colorScale;
uniform float rad_max;
layout (location = 0) out vec4 fragColor;
vec3 getRGB(float value) {
return texture(colorScale, vec2(value, 0)).rgb;
}
void main() {
float dt = texelFetch(siteDT, ivec2(gl_FragCoord.xy), 0).r;
if (dt > rad_max)
discard;
else {
vec4 accum = texelFetch(accumTex, ivec2(gl_FragCoord.xy), 0);
float value = (accum.g == 0.0) ? 0.0 : accum.r / accum.g;
fragColor = vec4(getRGB(value), 1.0 - dt / rad_max);
}
}
)EOF");
m_program2->link();
}
void VoronoiSplatRenderer::setupVAOs()
{
gl.glGenBuffers(3, m_VBOs);
// sitesVAO: VBOs 0 & 1 are for sites & their values (init'd later)
m_sitesVAO.create();
m_sitesVAO.bind();
gl.glBindBuffer(GL_ARRAY_BUFFER, m_VBOs[0]);
int vertAttrib = m_program1->attributeLocation("vert");
gl.glVertexAttribPointer(vertAttrib, 2, GL_FLOAT, GL_FALSE, 0, 0);
gl.glEnableVertexAttribArray(vertAttrib);
gl.glBindBuffer(GL_ARRAY_BUFFER, m_VBOs[1]);
int valueAttrib = m_program1->attributeLocation("scalar");
gl.glVertexAttribPointer(valueAttrib, 1, GL_FLOAT, GL_FALSE, 0, 0);
gl.glEnableVertexAttribArray(valueAttrib);
m_sitesVAO.release();
// 2ndPassVAO: VBO 2 is a quad mapping the final texture to the framebuffer
m_2ndPassVAO.create();
m_2ndPassVAO.bind();
GLfloat verts[] = {-1.0f, -1.0f, -1.0f, 1.0f,
1.0f, -1.0f, 1.0f, 1.0f};
gl.glBindBuffer(GL_ARRAY_BUFFER, m_VBOs[2]);
gl.glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_DRAW);
vertAttrib = m_program2->attributeLocation("vert");
gl.glVertexAttribPointer(vertAttrib, 2, GL_FLOAT, GL_FALSE, 0, 0);
gl.glEnableVertexAttribArray(vertAttrib);
m_2ndPassVAO.release();
}
void VoronoiSplatRenderer::setupTextures()
{
gl.glGenTextures(2, m_textures);
// Used for colorScale lookup in the frag shader
// (2D texture for compatibility; used to be a 1D texture)
gl.glGenTextures(1, &m_colormapTex);
gl.glBindTexture(GL_TEXTURE_2D, m_colormapTex);
gl.glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, Colormap::SAMPLES, 1, 0, GL_RGB,
GL_FLOAT, 0);
gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
}
VoronoiSplatRenderer::~VoronoiSplatRenderer()
{
gl.glDeleteBuffers(3, m_VBOs);
gl.glDeleteTextures(2, m_textures);
gl.glDeleteTextures(1, &m_colormapTex);
gl.glDeleteFramebuffers(1, &m_FBO);
delete m_program1;
delete m_program2;
}
void VoronoiSplatRenderer::resizeTextures()
{
// textures[0] stores the DT values for each pixel
gl.glBindTexture(GL_TEXTURE_2D, m_textures[0]);
gl.glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, m_size.width(),
m_size.height(), 0, GL_RED, GL_FLOAT, 0);
gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
// textures[1] is the result of the first pass
gl.glBindTexture(GL_TEXTURE_2D, m_textures[1]);
gl.glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, m_size.width(),
m_size.height(), 0, GL_RGBA, GL_FLOAT, 0);
gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
}
QOpenGLFramebufferObject *VoronoiSplatRenderer::createFramebufferObject(const QSize &size)
{
int baseSize = nextPow2(std::min(size.width(), size.height()));
m_size.setWidth(baseSize);
m_size.setHeight(baseSize);
resizeTextures();
return QQuickFramebufferObject::Renderer::createFramebufferObject(m_size);
}
void VoronoiSplatRenderer::render()
{
// Update OpenGL buffers and textures as needed
if (m_sitesChanged) {
updateSites();
}
if (m_valuesChanged) {
updateValues();
}
if (m_colorScaleChanged) {
updateColorScale();
}
int originalFBO;
gl.glGetIntegerv(GL_FRAMEBUFFER_BINDING, &originalFBO);
gl.glBindFramebuffer(GL_FRAMEBUFFER, m_FBO);
// First pass
m_program1->bind();
m_program1->setUniformValue("rad_max", 20.0f);
m_program1->setUniformValue("rad_blur", RAD_BLUR);
m_program1->setUniformValue("fb_size", float(m_size.width()));
gl.glActiveTexture(GL_TEXTURE0);
gl.glBindTexture(GL_TEXTURE_2D, m_textures[0]);
m_program1->setUniformValue("siteDT", 0);
gl.glEnable(GL_POINT_SPRITE);
gl.glEnable(GL_PROGRAM_POINT_SIZE);
gl.glEnable(GL_BLEND);
gl.glBlendFunc(GL_ONE, GL_ZERO);
// First, we draw to an intermediate texture, which is used as input for the
// second pass
gl.glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_TEXTURE_2D, m_textures[1], 0);
gl.glClearColor(0, 0, 0, 1);
gl.glClear(GL_COLOR_BUFFER_BIT);
m_sitesVAO.bind();
gl.glDrawArrays(GL_POINTS, 0, m_values->size());
m_sitesVAO.release();
m_program1->release();
// For some reason this call makes the splat circle of the correct size
//m_window->resetOpenGLState();
// Second pass
m_program2->bind();
m_program2->setUniformValue("rad_max", 20.0f);
gl.glActiveTexture(GL_TEXTURE0);
gl.glBindTexture(GL_TEXTURE_2D, m_textures[0]);
m_program2->setUniformValue("siteDT", 0);
gl.glActiveTexture(GL_TEXTURE1);
gl.glBindTexture(GL_TEXTURE_2D, m_textures[1]);
m_program2->setUniformValue("accumTex", 1);
gl.glActiveTexture(GL_TEXTURE2);
gl.glBindTexture(GL_TEXTURE_2D, m_colormapTex);
m_program2->setUniformValue("colorScale", 2);
gl.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
// We now render to the QQuickFramebufferObject's FBO
gl.glBindFramebuffer(GL_FRAMEBUFFER, originalFBO);
gl.glClearColor(0, 0, 0, 0);
gl.glClear(GL_COLOR_BUFFER_BIT);
m_2ndPassVAO.bind();
gl.glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
m_2ndPassVAO.release();
m_program2->release();
m_window->resetOpenGLState();
}
void VoronoiSplatRenderer::synchronize(QQuickFramebufferObject *item)
{
VoronoiSplat *splat = static_cast<VoronoiSplat *>(item);
m_sitesChanged = splat->sitesChanged();
m_valuesChanged = splat->valuesChanged();
m_colorScaleChanged = splat->colorScaleChanged();
// Reset these so that by the next synchronize() we have the correct values
splat->setSitesChanged(false);
splat->setValuesChanged(false);
splat->setColorScaleChanged(false);
m_sites = &(splat->sites());
m_values = &(splat->values());
m_cmap = &(splat->colorScale());
m_window = splat->window();
}
void VoronoiSplatRenderer::updateSites()
{
gl.glBindBuffer(GL_ARRAY_BUFFER, m_VBOs[0]);
gl.glBufferData(GL_ARRAY_BUFFER, m_sites->size() * sizeof(float),
m_sites->data(), GL_DYNAMIC_DRAW);
// Compute DT values for the new positions
computeDT();
m_sitesChanged = false;
}
void VoronoiSplatRenderer::updateValues()
{
gl.glBindBuffer(GL_ARRAY_BUFFER, m_VBOs[1]);
gl.glBufferData(GL_ARRAY_BUFFER, m_values->size() * sizeof(float),
m_values->data(), GL_DYNAMIC_DRAW);
m_valuesChanged = false;
}
void VoronoiSplatRenderer::updateColorScale()
{
gl.glActiveTexture(GL_TEXTURE0);
gl.glBindTexture(GL_TEXTURE_2D, m_colormapTex);
//gl.glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, Colormap::SAMPLES, 1, GL_RGB,
// GL_FLOAT, m_cmap->data());
gl.glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, Colormap::SAMPLES, 1, 0, GL_RGB,
GL_FLOAT, m_cmap->data());
m_colorScaleChanged = false;
}
void VoronoiSplatRenderer::computeDT()
{
int w = m_size.width(), h = m_size.height();
// Compute FT of the sites
std::vector<float> buf(w*h);
const std::vector<float> &sites = *m_sites;
for (unsigned i = 0; i < sites.size(); i += 2) {
buf[int(sites[i + 1])*h + int(sites[i])] = i/2.0f + 1.0f;
}
skelft2DFT(0, buf.data(), 0, 0, w, h, w);
// Compute DT of the sites (from the resident FT)
skelft2DDT(buf.data(), 0, 0, w, h);
// Upload result to lookup texture
gl.glActiveTexture(GL_TEXTURE0);
gl.glBindTexture(GL_TEXTURE_2D, m_textures[0]);
//gl.glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, w, h, GL_RED, GL_FLOAT,
// buf.data());
gl.glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F, w, h, 0, GL_RED, GL_FLOAT,
buf.data());
}
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