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#include <llmr/renderer/painter.hpp>
#include <llmr/renderer/text_bucket.hpp>
#include <llmr/style/style_layer.hpp>
#include <llmr/map/map.hpp>
#include <llmr/util/math.hpp>
#include <cmath>
using namespace llmr;
void Painter::renderText(TextBucket& bucket, std::shared_ptr<StyleLayer> layer_desc, const Tile::ID& id) {
// Abort early.
if (pass == Opaque) return;
if (!bucket.hasData()) return;
const TextProperties &properties = layer_desc->getProperties<TextProperties>();
mat4 exMatrix;
matrix::copy(exMatrix, projMatrix);
if (bucket.properties.path == TextPathType::Curve) {
matrix::rotate_z(exMatrix, exMatrix, map.getState().getAngle());
}
// If layerStyle.size > bucket.info.fontSize then labels may collide
float fontSize = std::fmin(properties.size, bucket.properties.max_size);
matrix::scale(exMatrix, exMatrix, fontSize / 24.0f, fontSize / 24.0f, 1.0f);
// TODO: figure out whether we actually need to account for this while painting; we might already have
// done this during label placement.
// const mat4 &vtxMatrix = translatedMatrix(properties.translate, id, properties.translateAnchor);
useProgram(textShader->program);
textShader->setMatrix(matrix);
textShader->setExtrudeMatrix(exMatrix);
GlyphAtlas &glyphAtlas = *map.getGlyphAtlas();
glyphAtlas.bind();
textShader->setTextureSize({{static_cast<float>(glyphAtlas.width),
static_cast<float>(glyphAtlas.height)}});
// Convert the -pi..pi to an int8 range.
float angle = std::round((map.getState().getAngle()) / M_PI * 128);
// adjust min/max zooms for variable font sies
float zoomAdjust = log(fontSize / bucket.properties.max_size) / log(2);
textShader->setAngle((int32_t)(angle + 256) % 256);
textShader->setFlip(bucket.properties.path == TextPathType::Curve ? 1 : 0);
textShader->setZoom((map.getState().getNormalizedZoom() - zoomAdjust) * 10); // current zoom level
// Label fading
const timestamp duration = 300_milliseconds;
const timestamp currentTime = util::now();
std::deque<FrameSnapshot> &history = frameHistory.history;
// Remove frames until only one is outside the duration, or until there are only three
while (history.size() > 3 && history[1].t + duration < currentTime) {
history.pop_front();
}
if (history[1].t + duration < currentTime) {
history[0].z = history[1].z;
}
assert("there should never be less than three frames in the history" && (history.size() >= 3));
// Find the range of zoom levels we want to fade between
float startingZ = history.front().z;
const FrameSnapshot lastFrame = history.back();
float endingZ = lastFrame.z;
float lowZ = std::fmin(startingZ, endingZ);
float highZ = std::fmax(startingZ, endingZ);
// Calculate the speed of zooming, and how far it would zoom in terms of zoom levels in one duration
float zoomDiff = endingZ - history[1].z,
timeDiff = lastFrame.t - history[1].t;
float fadedist = zoomDiff / (timeDiff / duration);
#if defined(DEBUG)
if (std::isnan(fadedist)) fprintf(stderr, "fadedist should never be NaN\n");
#endif
// At end of a zoom when the zoom stops changing continue pretending to zoom at that speed
// bump is how much farther it would have been if it had continued zooming at the same rate
float bump = (currentTime - lastFrame.t) / duration * fadedist;
textShader->setFadeDist(fadedist * 10);
textShader->setMinFadeZoom(std::floor(lowZ * 10));
textShader->setMaxFadeZoom(std::floor(highZ * 10));
textShader->setFadeZoom((map.getState().getNormalizedZoom() + bump) * 10);
// This defines the gamma around the SDF cutoff value.
const float sdfGamma = 0.75f / 10.0f;
// Our signed distance fields are scaled so that 1 pixel is scaled to 32 pixels.
// Our cutoff between positive and negative values is hard coded to 64 (== 2 pixels).
// This means that our 6/8 of the value range lies outside the glyph outline.
const float sdfOffset = (256.0f - 64.0f) / 32.0f;
// Currently, all of our fonts are rendered with a font size of 24px.
const float sdfFontSize = 24.0f;
// The default gamma value has to be adjust for the current pixelratio so that we're not drawing
// blurry font on retina screens.
const float gamma = sdfGamma * sdfFontSize / fontSize / map.getState().getPixelRatio();
// We're drawing in the translucent pass which is bottom-to-top, so we need
// to draw the halo first.
if (properties.halo_color[3] > 0.0f) {
const float haloWidth = util::clamp((sdfOffset - properties.halo_width / (fontSize / sdfFontSize)) / 8.0f, 0.0f, 1.0f);
if (properties.halo_blur != 0.0f) {
// We are converting the halo_blur value to current screen pixels.
// Then we're dividing it by two because the gamma value is added/subtracted into both
// directions in the shader, but the halo_blur describes the entire width of the blur.
// Note that this does *not* have to be adjusted for retina screens, because we want the
// same blur width when we explicitly specify one.
textShader->setGamma((properties.halo_blur / (fontSize / sdfFontSize)) / 8.0f / 2.0f);
} else {
textShader->setGamma(sdfGamma);
}
if (properties.opacity < 1.0f) {
Color color = properties.halo_color;
color[0] *= properties.opacity;
color[1] *= properties.opacity;
color[2] *= properties.opacity;
color[3] *= properties.opacity;
textShader->setColor(color);
} else {
textShader->setColor(properties.halo_color);
}
textShader->setBuffer(haloWidth);
glDepthRange(strata, 1.0f);
bucket.drawGlyphs(*textShader);
}
if (properties.color[3] > 0.0f) {
// Then, we draw the text over the halo
textShader->setGamma(gamma);
if (properties.opacity < 1.0f) {
Color color = properties.color;
color[0] *= properties.opacity;
color[1] *= properties.opacity;
color[2] *= properties.opacity;
color[3] *= properties.opacity;
textShader->setColor(color);
} else {
textShader->setColor(properties.color);
}
textShader->setBuffer((256.0f - 64.0f) / 256.0f);
glDepthRange(strata + strata_epsilon, 1.0f);
bucket.drawGlyphs(*textShader);
}
}
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