Show blurhashes for image events

LICENSES/MIT.txt

@@ -0,0 +1,19 @@
+MIT License Copyright (c) <year> <copyright holders>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is furnished
+to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice (including the next
+paragraph) shall be included in all copies or substantial portions of the
+Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
+OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

imports/NeoChat/Component/FullScreenImage.qml

@@ -11,6 +11,9 @@ ApplicationWindow {
 
     property string filename
     property url localPath
+    property string blurhash: ""
+    property int imageWidth: -1
+    property int imageHeight: -1
 
     flags: Qt.FramelessWindowHint | Qt.WA_TranslucentBackground
     visibility: Qt.WindowFullScreen
@@ -29,22 +32,29 @@ ApplicationWindow {
     }
 
     BusyIndicator {
-	visible: image.status !== Image.Ready
-	anchors.centerIn: parent
-	running: visible
+        visible: image.status !== Image.Ready && root.blurhash === ""
+        anchors.centerIn: parent
+        running: visible
     }
 
     AnimatedImage {
-	id: image
+	    id: image
         anchors.centerIn: parent
 
-        width: Math.min(sourceSize.width, root.width)
-        height: Math.min(sourceSize.height, root.height)
+        width: Math.min(root.imageWidth !== -1 ? root.imageWidth : sourceSize.width, root.width)
+        height: Math.min(root.imageHeight !== -1 ? root.imageWidth : sourceSize.height, root.height)
 
-        cache: false
         fillMode: Image.PreserveAspectFit
 
         source: localPath
+
+        Image {
+            anchors.centerIn: parent
+            width: image.width
+            height: image.height
+            source: root.blurhash !== "" ? ("image://blurhash/" + root.blurhash) : ""
+            visible: root.blurhash !== "" && parent.status !== Image.Ready
+        }
     }
 
     Button {

imports/NeoChat/Component/Timeline/ImageDelegate.qml

@@ -29,6 +29,12 @@ Image {
 
     source: "image://mxc/" + mediaId
 
+    Image {
+        anchors.fill: parent
+        source: "image://blurhash/" + content.info["xyz.amorgan.blurhash"]
+        visible: parent.status !== Image.Ready
+    }
+
     fillMode: Image.PreserveAspectFit
 
     ToolTip.text: display

imports/NeoChat/Page/RoomPage.qml

@@ -457,7 +457,7 @@ Kirigami.ScrollablePage {
                             acceptedButtons: Qt.LeftButton
                             onLongPressed: openFileContext(author, model.display, eventId, toolTip, progressInfo, parent)
                             onTapped: {
-                                fullScreenImage.createObject(parent, {"filename": eventId, "localPath": currentRoom.urlToDownload(eventId)}).showFullScreen()
+                                fullScreenImage.createObject(parent, {"filename": eventId, "localPath": currentRoom.urlToDownload(eventId), "blurhash": model.content.info["xyz.amorgan.blurhash"], "imageWidth": content.info.w, "imageHeight": content.info.h}).showFullScreen()
                             }
                         }
                     }

src/CMakeLists.txt

@@ -34,6 +34,8 @@ add_executable(neochat
     commandmodel.cpp
     webshortcutmodel.cpp
     spellcheckhighlighter.cpp
+    blurhash.cpp
+    blurhashimageprovider.cpp
     ../res.qrc
 )
 

src/blurhash.cpp

@@ -0,0 +1,186 @@
+// SPDX-FileCopyrightText: 2018 Wolt Enterprises
+// SPDX-License-Identifiert: MIT
+
+#include "blurhash.h"
+
+static char chars[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz#$%*+,-.:;=?@[]^_{|}~";
+
+static inline int linearTosRGB(float value)
+{
+    float v = fmaxf(0, fminf(1, value));
+    if (v <= 0.0031308)
+        return v * 12.92 * 255 + 0.5;
+    else
+        return (1.055 * powf(v, 1 / 2.4) - 0.055) * 255 + 0.5;
+}
+
+static inline float sRGBToLinear(int value)
+{
+    float v = (float)value / 255;
+    if (v <= 0.04045)
+        return v / 12.92;
+    else
+        return powf((v + 0.055) / 1.055, 2.4);
+}
+
+static inline float signPow(float value, float exp)
+{
+    return copysignf(powf(fabsf(value), exp), value);
+}
+
+static inline uint8_t clampToUByte(int *src)
+{
+    if (*src >= 0 && *src <= 255) {
+        return *src;
+    }
+    return (*src < 0) ? 0 : 255;
+}
+
+static inline uint8_t *createByteArray(int size)
+{
+    return (uint8_t *)malloc(size * sizeof(uint8_t));
+}
+
+int decodeToInt(const char *string, int start, int end)
+{
+    int value = 0;
+    for (int iter1 = start; iter1 < end; iter1++) {
+        int index = -1;
+        for (int iter2 = 0; iter2 < 83; iter2++) {
+            if (chars[iter2] == string[iter1]) {
+                index = iter2;
+                break;
+            }
+        }
+        if (index == -1) {
+            return -1;
+        }
+        value = value * 83 + index;
+    }
+    return value;
+}
+
+bool isValidBlurhash(const char *blurhash)
+{
+    const int hashLength = strlen(blurhash);
+
+    if (!blurhash || strlen(blurhash) < 6) {
+        return false;
+    }
+
+    int sizeFlag = decodeToInt(blurhash, 0, 1);
+    int numY = (int)floorf(sizeFlag / 9) + 1;
+    int numX = (sizeFlag % 9) + 1;
+
+    return hashLength == 4 + 2 * numX * numY;
+}
+
+void decodeDC(int value, float *r, float *g, float *b)
+{
+    *r = sRGBToLinear(value >> 16);
+    *g = sRGBToLinear((value >> 8) & 255);
+    *b = sRGBToLinear(value & 255);
+}
+
+void decodeAC(int value, float maximumValue, float *r, float *g, float *b)
+{
+    int quantR = (int)floorf(value / (19 * 19));
+    int quantG = (int)floorf(value / 19) % 19;
+    int quantB = (int)value % 19;
+
+    *r = signPow(((float)quantR - 9) / 9, 2.0) * maximumValue;
+    *g = signPow(((float)quantG - 9) / 9, 2.0) * maximumValue;
+    *b = signPow(((float)quantB - 9) / 9, 2.0) * maximumValue;
+}
+
+int decodeToArray(const char *blurhash, int width, int height, int punch, int nChannels, uint8_t *pixelArray)
+{
+    if (!isValidBlurhash(blurhash)) {
+        return -1;
+    }
+    if (punch < 1) {
+        punch = 1;
+    }
+
+    int sizeFlag = decodeToInt(blurhash, 0, 1);
+    int numY = (int)floorf(sizeFlag / 9) + 1;
+    int numX = (sizeFlag % 9) + 1;
+    int iter = 0;
+
+    float r = 0, g = 0, b = 0;
+    int quantizedMaxValue = decodeToInt(blurhash, 1, 2);
+    if (quantizedMaxValue == -1) {
+        return -1;
+    }
+
+    float maxValue = ((float)(quantizedMaxValue + 1)) / 166;
+
+    int colors_size = numX * numY;
+    float colors[colors_size][3];
+
+    for (iter = 0; iter < colors_size; iter++) {
+        if (iter == 0) {
+            int value = decodeToInt(blurhash, 2, 6);
+            if (value == -1) {
+                return -1;
+            }
+            decodeDC(value, &r, &g, &b);
+            colors[iter][0] = r;
+            colors[iter][1] = g;
+            colors[iter][2] = b;
+        } else {
+            int value = decodeToInt(blurhash, 4 + iter * 2, 6 + iter * 2);
+            if (value == -1) {
+                return -1;
+            }
+            decodeAC(value, maxValue * punch, &r, &g, &b);
+            colors[iter][0] = r;
+            colors[iter][1] = g;
+            colors[iter][2] = b;
+        }
+    }
+
+    int bytesPerRow = width * nChannels;
+    int x = 0, y = 0, i = 0, j = 0;
+    int intR = 0, intG = 0, intB = 0;
+
+    for (y = 0; y < height; y++) {
+        for (x = 0; x < width; x++) {
+            float r = 0, g = 0, b = 0;
+
+            for (j = 0; j < numY; j++) {
+                for (i = 0; i < numX; i++) {
+                    float basics = cos((M_PI * x * i) / width) * cos((M_PI * y * j) / height);
+                    int idx = i + j * numX;
+                    r += colors[idx][0] * basics;
+                    g += colors[idx][1] * basics;
+                    b += colors[idx][2] * basics;
+                }
+            }
+
+            intR = linearTosRGB(r);
+            intG = linearTosRGB(g);
+            intB = linearTosRGB(b);
+
+            pixelArray[nChannels * x + 0 + y * bytesPerRow] = clampToUByte(&intR);
+            pixelArray[nChannels * x + 1 + y * bytesPerRow] = clampToUByte(&intG);
+            pixelArray[nChannels * x + 2 + y * bytesPerRow] = clampToUByte(&intB);
+
+            if (nChannels == 4) {
+                pixelArray[nChannels * x + 3 + y * bytesPerRow] = 255;
+            }
+        }
+    }
+    return 0;
+}
+
+uint8_t *decode(const char *blurhash, int width, int height, int punch, int nChannels)
+{
+    int bytesPerRow = width * nChannels;
+    uint8_t *pixelArray = createByteArray(bytesPerRow * height);
+
+    if (decodeToArray(blurhash, width, height, punch, nChannels, pixelArray) == -1) {
+        return NULL;
+    }
+    return pixelArray;
+}

src/blurhash.h

@@ -0,0 +1,14 @@
+// SPDX-FileCopyrightText: 2018 Wolt Enterprises
+// SPDX-License-Identifiert: MIT
+
+#pragma once
+
+#include <math.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+uint8_t *decode(const char *blurhash, int width, int height, int punch, int nChannels);
+
+bool isValidBlurhash(const char *blurhash);

src/blurhashimageprovider.cpp

@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#include "blurhashimageprovider.h"
+
+#include <QImage>
+#include <QString>
+
+#include "blurhash.h"
+
+BlurhashImageProvider::BlurhashImageProvider()
+    : QQuickImageProvider(QQuickImageProvider::Image)
+{
+}
+
+QImage BlurhashImageProvider::requestImage(const QString &id, QSize *size, const QSize &requestedSize)
+{
+    if (id.isEmpty()) {
+        return QImage();
+    }
+    *size = requestedSize;
+    if (size->width() == -1) {
+        size->setWidth(256);
+    }
+    if (size->height() == -1) {
+        size->setHeight(256);
+    }
+    auto data = decode(QUrl::fromPercentEncoding(id.toLatin1()).toLatin1().data(), size->width(), size->height(), 1, 3);
+    QImage image(data, size->width(), size->height(), size->width() * 3, QImage::Format_RGB888, free, data);
+    return image;
+}

src/blurhashimageprovider.h

@@ -0,0 +1,13 @@
+// SPDX-FileCopyrightText: 2021 Tobias Fella <fella@posteo.de>
+// SPDX-License-Identifier: LGPL-2.0-or-later
+
+#pragma once
+
+#include <QQuickImageProvider>
+
+class BlurhashImageProvider : public QQuickImageProvider
+{
+public:
+    BlurhashImageProvider();
+    QImage requestImage(const QString &id, QSize *size, const QSize &requestedSize) override;
+};

src/main.cpp

@@ -59,6 +59,7 @@
 #include "webshortcutmodel.h"
 #include "spellcheckhighlighter.h"
 #include "customemojimodel.h"
+#include "blurhashimageprovider.h"
 #ifdef HAVE_COLORSCHEME
 #include "colorschemer.h"
 #endif
@@ -212,6 +213,7 @@ int main(int argc, char *argv[])
 
     engine.addImportPath("qrc:/imports");
     engine.addImageProvider(QLatin1String("mxc"), new MatrixImageProvider);
+    engine.addImageProvider(QLatin1String("blurhash"), new BlurhashImageProvider);
 
     engine.load(QUrl(QStringLiteral("qrc:/qml/main.qml")));
     if (engine.rootObjects().isEmpty()) {