Port distancefield debugging code from OpenGL to RHI

Task-number: QTBUG-84623
Change-Id: I26941eacf5ad97ed3c7c6e7d7ad3beec7f0c6fa3
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

4 files changed, 42 insertions, 159 deletions

diff --git a/src/quick/scenegraph/qsgadaptationlayer.cpp b/src/quick/scenegraph/qsgadaptationlayer.cpp
index 3ee5d6fdb7..226c580fb2 100644
--- a/src/quick/scenegraph/qsgadaptationlayer.cpp
+++ b/src/quick/scenegraph/qsgadaptationlayer.cpp
@@ -206,7 +206,7 @@ void QSGDistanceFieldGlyphCache::update()
 
 #if defined(QSG_DISTANCEFIELD_CACHE_DEBUG)
     for (Texture texture : qAsConst(m_textures))
-        saveTexture(texture.textureId, texture.size.width(), texture.size.height());
+        saveTexture(texture.texture, m_referenceFont.familyName());
 #endif
 
     if (QSG_LOG_TIME_GLYPH().isDebugEnabled()) {
@@ -315,163 +315,6 @@ void QSGDistanceFieldGlyphCache::updateRhiTexture(QRhiTexture *oldTex, QRhiTextu
     }
 }
 
-#if defined(QSG_DISTANCEFIELD_CACHE_DEBUG)
-#include <qopenglfunctions.h>
-
-void QSGDistanceFieldGlyphCache::saveTexture(GLuint textureId, int width, int height) const
-{
-    QOpenGLFunctions *functions = QOpenGLContext::currentContext()->functions();
-
-    GLuint fboId;
-    functions->glGenFramebuffers(1, &fboId);
-
-    GLuint tmpTexture = 0;
-    functions->glGenTextures(1, &tmpTexture);
-    functions->glBindTexture(GL_TEXTURE_2D, tmpTexture);
-    functions->glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
-    functions->glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-    functions->glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
-    functions->glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-    functions->glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-    functions->glBindTexture(GL_TEXTURE_2D, 0);
-
-    functions->glBindFramebuffer(GL_FRAMEBUFFER_EXT, fboId);
-    functions->glFramebufferTexture2D(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D,
-                                      tmpTexture, 0);
-
-    functions->glActiveTexture(GL_TEXTURE0);
-    functions->glBindTexture(GL_TEXTURE_2D, textureId);
-
-    functions->glDisable(GL_STENCIL_TEST);
-    functions->glDisable(GL_DEPTH_TEST);
-    functions->glDisable(GL_SCISSOR_TEST);
-    functions->glDisable(GL_BLEND);
-
-    GLfloat textureCoordinateArray[8];
-    textureCoordinateArray[0] = 0.0f;
-    textureCoordinateArray[1] = 0.0f;
-    textureCoordinateArray[2] = 1.0f;
-    textureCoordinateArray[3] = 0.0f;
-    textureCoordinateArray[4] = 1.0f;
-    textureCoordinateArray[5] = 1.0f;
-    textureCoordinateArray[6] = 0.0f;
-    textureCoordinateArray[7] = 1.0f;
-
-    GLfloat vertexCoordinateArray[8];
-    vertexCoordinateArray[0] = -1.0f;
-    vertexCoordinateArray[1] = -1.0f;
-    vertexCoordinateArray[2] =  1.0f;
-    vertexCoordinateArray[3] = -1.0f;
-    vertexCoordinateArray[4] =  1.0f;
-    vertexCoordinateArray[5] =  1.0f;
-    vertexCoordinateArray[6] = -1.0f;
-    vertexCoordinateArray[7] =  1.0f;
-
-    functions->glViewport(0, 0, width, height);
-    functions->glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, vertexCoordinateArray);
-    functions->glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, textureCoordinateArray);
-
-    {
-        static const char *vertexShaderSource =
-                "attribute vec4      vertexCoordsArray; \n"
-                "attribute vec2      textureCoordArray; \n"
-                "varying   vec2      textureCoords;     \n"
-                "void main(void) \n"
-                "{ \n"
-                "    gl_Position = vertexCoordsArray;   \n"
-                "    textureCoords = textureCoordArray; \n"
-                "} \n";
-
-        static const char *fragmentShaderSource =
-                "varying   vec2      textureCoords; \n"
-                "uniform   sampler2D         texture;       \n"
-                "void main() \n"
-                "{ \n"
-                "    gl_FragColor = texture2D(texture, textureCoords); \n"
-                "} \n";
-
-        GLuint vertexShader = functions->glCreateShader(GL_VERTEX_SHADER);
-        GLuint fragmentShader = functions->glCreateShader(GL_FRAGMENT_SHADER);
-
-        if (vertexShader == 0 || fragmentShader == 0) {
-            GLenum error = functions->glGetError();
-            qWarning("QSGDistanceFieldGlyphCache::saveTexture: Failed to create shaders. (GL error: %x)",
-                     error);
-            return;
-        }
-
-        functions->glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
-        functions->glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
-        functions->glCompileShader(vertexShader);
-
-        GLint len = 1;
-        functions->glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &len);
-
-        char infoLog[2048];
-        functions->glGetShaderInfoLog(vertexShader, 2048, NULL, infoLog);
-        if (qstrlen(infoLog) > 0)
-            qWarning("Problems compiling vertex shader:\n %s", infoLog);
-
-        functions->glCompileShader(fragmentShader);
-        functions->glGetShaderInfoLog(fragmentShader, 2048, NULL, infoLog);
-        if (qstrlen(infoLog) > 0)
-            qWarning("Problems compiling fragment shader:\n %s", infoLog);
-
-        GLuint shaderProgram = functions->glCreateProgram();
-        functions->glAttachShader(shaderProgram, vertexShader);
-        functions->glAttachShader(shaderProgram, fragmentShader);
-
-        functions->glBindAttribLocation(shaderProgram, 0, "vertexCoordsArray");
-        functions->glBindAttribLocation(shaderProgram, 1, "textureCoordArray");
-
-        functions->glLinkProgram(shaderProgram);
-        functions->glGetProgramInfoLog(shaderProgram, 2048, NULL, infoLog);
-        if (qstrlen(infoLog) > 0)
-            qWarning("Problems linking shaders:\n %s", infoLog);
-
-        functions->glUseProgram(shaderProgram);
-        functions->glEnableVertexAttribArray(0);
-        functions->glEnableVertexAttribArray(1);
-
-        int textureUniformLocation = functions->glGetUniformLocation(shaderProgram, "texture");
-        functions->glUniform1i(textureUniformLocation, 0);
-    }
-
-    functions->glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
-
-    {
-        GLenum error = functions->glGetError();
-        if (error != GL_NO_ERROR)
-            qWarning("glDrawArrays reported error 0x%x", error);
-    }
-
-    uchar *data = new uchar[width * height * 4];
-
-    functions->glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, data);
-
-    QImage image(data, width, height, QImage::Format_ARGB32);
-
-    QByteArray fileName = m_referenceFont.familyName().toLatin1() + '_' + QByteArray::number(textureId);
-    fileName = fileName.replace('/', '_').replace(' ', '_') + ".png";
-
-    image.save(QString::fromLocal8Bit(fileName));
-
-    {
-        GLenum error = functions->glGetError();
-        if (error != GL_NO_ERROR)
-            qWarning("glReadPixels reported error 0x%x", error);
-    }
-
-    functions->glDisableVertexAttribArray(0);
-    functions->glDisableVertexAttribArray(1);
-
-    functions->glDeleteFramebuffers(1, &fboId);
-    functions->glDeleteTextures(1, &tmpTexture);
-
-    delete[] data;
-}
-#endif
-
 void QSGNodeVisitorEx::visitChildren(QSGNode *node)
 {
     for (QSGNode *child = node->firstChild(); child; child = child->nextSibling()) {
diff --git a/src/quick/scenegraph/qsgadaptationlayer_p.h b/src/quick/scenegraph/qsgadaptationlayer_p.h
index 31f90bd0b2..657678ec37 100644
--- a/src/quick/scenegraph/qsgadaptationlayer_p.h
+++ b/src/quick/scenegraph/qsgadaptationlayer_p.h
@@ -520,7 +520,7 @@ protected:
     GlyphData &emptyData(glyph_t glyph);
 
 #if defined(QSG_DISTANCEFIELD_CACHE_DEBUG)
-    void saveTexture(GLuint textureId, int width, int height) const;
+    virtual void saveTexture(QRhiTexture *texture, const QString &nameBase) const = 0;
 #endif
 
     bool m_doubleGlyphResolution;
diff --git a/src/quick/scenegraph/qsgrhidistancefieldglyphcache.cpp b/src/quick/scenegraph/qsgrhidistancefieldglyphcache.cpp
index 6e7e2b5118..91eda8ebfc 100644
--- a/src/quick/scenegraph/qsgrhidistancefieldglyphcache.cpp
+++ b/src/quick/scenegraph/qsgrhidistancefieldglyphcache.cpp
@@ -565,4 +565,40 @@ bool QSGRhiDistanceFieldGlyphCache::eightBitFormatIsAlphaSwizzled() const
     return !m_rhi->isFeatureSupported(QRhi::RedOrAlpha8IsRed);
 }
 
+#if defined(QSG_DISTANCEFIELD_CACHE_DEBUG)
+void QSGRhiDistanceFieldGlyphCache::saveTexture(QRhiTexture *texture, const QString &nameBase) const
+{
+    quint64 textureId = texture->nativeTexture().object;
+    QString fileName = nameBase + QLatin1Char('_') + QString::number(textureId, 16);
+    fileName.replace(QLatin1Char('/'), QLatin1Char('_'));
+    fileName.replace(QLatin1Char(' '), QLatin1Char('_'));
+    fileName.append(QLatin1String(".png"));
+
+    QRhiReadbackResult *rbResult = new QRhiReadbackResult;
+    rbResult->completed = [rbResult, fileName] {
+        const QSize size = rbResult->pixelSize;
+        const qint64 numPixels = qint64(size.width()) * size.height();
+        if (numPixels == rbResult->data.size()) {
+            // 1 bpp data, may be packed; copy it to ensure QImage scanline alignment
+            QImage image(size, QImage::Format_Grayscale8);
+            const char *p = rbResult->data.constData();
+            for (int i = 0; i < size.height(); i++)
+                memcpy(image.scanLine(i), p + (i * size.width()), size.width());
+            image.save(fileName);
+        } else if (4 * numPixels == rbResult->data.size()) {
+            // 4 bpp data
+            const uchar *p = reinterpret_cast<const uchar *>(rbResult->data.constData());
+            QImage image(p, size.width(), size.height(), QImage::Format_RGBA8888);
+            image.save(fileName);
+        } else {
+            qWarning("Unhandled data format in glyph texture");
+        }
+        delete rbResult;
+    };
+
+    QRhiReadbackDescription rb(texture);
+    m_resourceUpdates->readBackTexture(rb, rbResult);
+}
+#endif
+
 QT_END_NAMESPACE
diff --git a/src/quick/scenegraph/qsgrhidistancefieldglyphcache_p.h b/src/quick/scenegraph/qsgrhidistancefieldglyphcache_p.h
index d43b0aa5d4..6441188dfe 100644
--- a/src/quick/scenegraph/qsgrhidistancefieldglyphcache_p.h
+++ b/src/quick/scenegraph/qsgrhidistancefieldglyphcache_p.h
@@ -79,6 +79,10 @@ public:
 
     bool eightBitFormatIsAlphaSwizzled() const override;
 
+#if defined(QSG_DISTANCEFIELD_CACHE_DEBUG)
+    void saveTexture(QRhiTexture *texture, const QString &nameBase) const override;
+#endif
+
 private:
     bool loadPregeneratedCache(const QRawFont &font);