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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;
static const float PADDING = 10.0f; // in screen pixels
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;
}
VoronoiSplatTexture::VoronoiSplatTexture(const QSize &size)
: gl(QOpenGLContext::currentContext())
, m_cmap(3*COLORMAP_SAMPLES)
{
int baseSize = nextPow2(std::min(size.width(), size.height()));
m_size.setWidth(baseSize);
m_size.setHeight(baseSize);
gl.glGenFramebuffers(1, &m_FBO);
setupShaders();
setupVAOs();
setupTextures();
}
void VoronoiSplatTexture::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 colormap;
uniform float rad_max;
layout (location = 0) out vec4 fragColor;
vec3 getRGB(float value) {
return texture(colormap, vec2(mix(0.005, 0.995, 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.rgb = getRGB(value);
fragColor.a = 1.0 - dt / rad_max;
}
}
)EOF");
m_program2->link();
}
void VoronoiSplatTexture::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 VoronoiSplatTexture::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
// (using a 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);
// The output texture
gl.glGenTextures(1, &m_tex);
gl.glBindTexture(GL_TEXTURE_2D, m_tex);
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_MAG_FILTER, GL_LINEAR);
gl.glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
}
VoronoiSplatTexture::~VoronoiSplatTexture()
{
gl.glDeleteBuffers(3, m_VBOs);
gl.glDeleteTextures(2, m_textures);
gl.glDeleteTextures(1, &m_colormapTex);
gl.glDeleteTextures(1, &m_tex);
gl.glDeleteFramebuffers(1, &m_FBO);
delete m_program1;
delete m_program2;
}
void VoronoiSplatTexture::bind()
{
gl.glBindTexture(GL_TEXTURE_2D, m_tex);
}
bool VoronoiSplatTexture::updateTexture()
{
if (!m_sitesChanged && !m_valuesChanged && !m_colormapChanged) {
// Texture is already updated
return false;
}
// Update OpenGL buffers and textures as needed
if (m_sitesChanged) {
updateSites();
}
if (m_valuesChanged) {
updateValues();
}
if (m_colormapChanged) {
updateColormap();
}
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();
// 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);
// We now render to the output texture
gl.glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
GL_TEXTURE_2D, m_tex, 0);
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();
return true;
}
void VoronoiSplatTexture::updateSites()
{
// 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();
m_sitesChanged = false;
}
void VoronoiSplatTexture::updateValues()
{
// 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);
m_valuesChanged = false;
}
void VoronoiSplatTexture::updateColormap()
{
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());
m_colormapChanged = false;
}
void VoronoiSplatTexture::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 VoronoiSplatTexture::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, PADDING, m_size.width() - 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, m_size.height() - PADDING, PADDING);
for (unsigned i = 0; i < points.n_rows; i++) {
m_sites[2*i + 1] = sy(col[i]);
}
m_sitesChanged = true;
}
void VoronoiSplatTexture::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);
m_valuesChanged = true;
}
void VoronoiSplatTexture::setColormap(const ColorScale *scale)
{
if (!scale) {
return;
}
float t = scale->min();
float step = (scale->max() - scale->min()) / COLORMAP_SAMPLES;
qreal r, g, b;
for (unsigned i = 0; i < m_cmap.size(); i += 3) {
scale->color(t).getRgbF(&r, &g, &b);
m_cmap[i + 0] = r;
m_cmap[i + 1] = g;
m_cmap[i + 2] = b;
t += step;
}
m_colormapChanged = true;
}
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