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#include "voronoisplat.h"
#include <algorithm>
#include <QQuickWindow>
#include <QOpenGLFramebufferObject>
#include "scale.h"
#include "skelft.h"
static const float RAD_BLUR = 5.0f;
static const int COLORMAP_SAMPLES = 128;
VoronoiSplatRenderer::VoronoiSplatRenderer(const QSize &size)
: m_item(0)
, gl(QOpenGLContext::currentContext())
, m_size(size)
{
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;
fragColor = vec4(0.25, 0.5, 0, 0);
return;
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
layout (location = 0) out vec4 fragColor;
uniform sampler2D siteDT;
uniform sampler2D accumTex;
uniform sampler2D colormap;
uniform float rad_max;
vec3 getRGB(float value) {
return texture2D(colormap, vec2(mix(0.005, 0.995, value), 1)).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);
// 1.0 is extra-accumulated because of white background
float value = 0.0f;
if (accum.g > 1.0)
value = (accum.r - 1.0) / (accum.g - 1.0);
fragColor.rgb = getRGB(value);
fragColor.a = 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();
gl.glBindBuffer(GL_ARRAY_BUFFER, m_VBOs[2]);
GLfloat verts[] = {-1.0f, -1.0f, -1.0f, 1.0f,
1.0f, -1.0f, 1.0f, 1.0f};
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);
// 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_RG, 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);
// Used for colormap lookup in the frag shader
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);
delete m_program1;
delete m_program2;
}
void VoronoiSplatRenderer::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)
copyPoints(points);
// Update VBO with the new data
gl.glBindBuffer(GL_ARRAY_BUFFER, m_VBOs[0]);
gl.glBufferData(GL_ARRAY_BUFFER, m_sites.size() * sizeof(float),
m_sites.data(), GL_STATIC_DRAW);
// Compute DT values for the new positions
computeDT();
}
void VoronoiSplatRenderer::copyPoints(const arma::mat &points)
{
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 tighly packed into 'm_sites' as [ (x1, y1), (x2, y2), ... ]
m_sites.resize(2*points.n_rows);
LinearScale<float> sx(minX, maxX, 1, m_size.width() - 1);
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, m_size.height() - 1, 1);
for (unsigned i = 0; i < points.n_rows; i++) {
m_sites[2*i + 1] = sy(col[i]);
}
}
void VoronoiSplatRenderer::computeDT()
{
int w = m_size.width(), h = m_size.height();
std::vector<float> buf(w*h, 0.0f);
for (unsigned i = 0; i < m_sites.size(); i += 2) {
buf[int(m_sites[i + 1])*h + int(m_sites[i])] = (float) i/2 + 1;
}
// Compute FT of the sites
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);
std::vector<GLfloat> dtTexData(2*w*h, 0.0f);
for (unsigned i = 0; i < buf.size(); i++) {
dtTexData[2*i] = buf[i];
}
// Upload result to lookup texture
gl.glBindTexture(GL_TEXTURE_2D, m_textures[0]);
gl.glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, w, h, GL_RG, GL_FLOAT,
dtTexData.data());
}
void VoronoiSplatRenderer::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);
// Update VBO with the new data
gl.glBindBuffer(GL_ARRAY_BUFFER, m_VBOs[1]);
gl.glBufferData(GL_ARRAY_BUFFER, m_values.size() * sizeof(float),
m_values.data(), GL_DYNAMIC_DRAW);
}
void VoronoiSplatRenderer::setColorMap(const ColorScale *scale)
{
if (!scale) {
return;
}
float t = scale->min();
float step = (scale->max() - scale->min()) / COLORMAP_SAMPLES;
qreal r, g, b;
std::vector<float> cmap(3*COLORMAP_SAMPLES); // R,G,B
for (int i = 0; i < 3*COLORMAP_SAMPLES; i += 3) {
scale->color(t).getRgbF(&r, &g, &b);
cmap[i + 0] = r;
cmap[i + 1] = g;
cmap[i + 2] = b;
t += step;
}
// Update texture data
gl.glBindTexture(GL_TEXTURE_2D, m_colorMapTex);
gl.glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, COLORMAP_SAMPLES, 1, GL_RGB,
GL_FLOAT, cmap.data());
}
QOpenGLFramebufferObject *VoronoiSplatRenderer::createFramebufferObject(const QSize &size)
{
return new QOpenGLFramebufferObject(size);
}
void VoronoiSplatRenderer::synchronize(QQuickFramebufferObject *item)
{
m_item = static_cast<VoronoiSplat *>(item);
if (m_item->colorScaleUpdated()) {
setColorMap(m_item->colorScale());
}
if (m_item->pointsUpdated()) {
setSites(m_item->points());
}
if (m_item->valuesUpdated()) {
setValues(m_item->values());
}
m_item->setUpdated(false);
}
void VoronoiSplatRenderer::render()
{
// Store the final texture to render to, as we use a two-pass rendering
// which first renders to an intermediate texture
GLint targetTexture;
gl.glGetFramebufferAttachmentParameteriv(GL_FRAMEBUFFER,
GL_COLOR_ATTACHMENT0, GL_FRAMEBUFFER_ATTACHMENT_OBJECT_NAME,
&targetTexture);
// The first pass
m_program1->bind();
m_program1->setUniformValue("rad_max", 20.0f);
m_program1->setUniformValue("rad_blur", RAD_BLUR);
m_program1->setUniformValue("fb_size", 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_ONE);
// In the first pass we draw to an intermediate texture, which is used as
// input for the next pass
gl.glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_TEXTURE_2D, m_textures[1], 0);
gl.glClearColor(1, 1, 1, 1);
gl.glClear(GL_COLOR_BUFFER_BIT);
m_sitesVAO.bind();
gl.glDrawArrays(GL_POINTS, 0, m_values.size());
m_sitesVAO.release();
m_program1->release();
// 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("colormap", 2);
gl.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
// Restore the original framebuffer texture
gl.glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_TEXTURE_2D, targetTexture, 0);
glClearColor(1, 1, 1, 1);
glClear(GL_COLOR_BUFFER_BIT);
m_2ndPassVAO.bind();
gl.glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
m_2ndPassVAO.release();
m_program2->release();
m_item->window()->resetOpenGLState();
}
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_colorScaleUpdated(false)
, m_pointsUpdated(false)
, m_valuesUpdated(false)
, m_colorScale(0)
{
setTextureFollowsItemSize(false);
}
QQuickFramebufferObject::Renderer *VoronoiSplat::createRenderer() const
{
int baseSize = nextPow2(std::min(width(), height()));
return new VoronoiSplatRenderer(QSize(baseSize, baseSize));
}
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