Add transparency toggle

src/DDSPreview.py

@@ -1,10 +1,12 @@
 import struct
 import sys
 import threading
+import enum
+from typing import Iterable
 
 from PyQt5.QtCore import QCoreApplication, qDebug, Qt
-from PyQt5.QtGui import QColor, QOpenGLBuffer, QOpenGLContext, QOpenGLDebugLogger, QOpenGLShader, QOpenGLShaderProgram, QOpenGLTexture, QOpenGLVersionProfile, QOpenGLVertexArrayObject, QSurfaceFormat
-from PyQt5.QtWidgets import QCheckBox, QDialog, QGridLayout, QLabel, QOpenGLWidget, QPushButton, QWidget
+from PyQt5.QtGui import QColor, QOpenGLBuffer, QOpenGLContext, QOpenGLDebugLogger, QOpenGLShader, QOpenGLShaderProgram, QOpenGLVersionProfile, QOpenGLVertexArrayObject, QSurfaceFormat, QMatrix4x4, QVector4D
+from PyQt5.QtWidgets import QColorDialog, QGridLayout, QLabel, QOpenGLWidget, QPushButton, QWidget, QComboBox 
 
 from DDS.DDSFile import DDSFile
 
@@ -53,47 +55,55 @@
 #version 150
 
 uniform sampler2D aTexture;
+uniform mat4 channelMatrix;
+uniform vec4 channelOffset;
 
 in vec2 texCoord;
 
 void main()
 {
-    gl_FragData[0] = texture(aTexture, texCoord);
+    gl_FragData[0] = channelMatrix *  texture(aTexture, texCoord) + channelOffset;
 }
 """
 
 fragmentShaderUInt = """
 #version 150
 
 uniform usampler2D aTexture;
+uniform mat4 channelMatrix;
+uniform vec4 channelOffset;
 
 in vec2 texCoord;
 
 void main()
 {
     // autofilled alpha is 1, so if we have a scaling factor, we need separate ones for luminance and alpha
-    gl_FragData[0] = texture(aTexture, texCoord);
+    gl_FragData[0] = channelMatrix * texture(aTexture, texCoord) + channelOffset;
 }
 """
 
 fragmentShaderSInt = """
 #version 150
 
 uniform isampler2D aTexture;
+uniform mat4 channelMatrix;
+uniform vec4 channelOffset;
 
 in vec2 texCoord;
 
 void main()
 {
     // autofilled alpha is 1, so if we have a scaling factor and offset, we need separate ones for luminance and alpha
-    gl_FragData[0] = texture(aTexture, texCoord);
+    gl_FragData[0] = channelMatrix * texture(aTexture, texCoord) + channelOffset;
 }
 """
 
 fragmentShaderCube = """
 #version 150
 
 uniform samplerCube aTexture;
+uniform mat4 channelMatrix;
+uniform vec4 channelOffset;
 
 in vec2 texCoord;
 
@@ -103,7 +113,7 @@
 {
     float theta = -2.0 * PI * texCoord.x;
     float phi = PI * texCoord.y;
-    gl_FragData[0] = texture(aTexture, vec3(sin(theta) * sin(phi), cos(theta) * sin(phi), cos(phi)));
+    gl_FragData[0] = channelMatrix * texture(aTexture, vec3(sin(theta) * sin(phi), cos(theta) * sin(phi), cos(phi))) + channelOffset;
 }
 """
 
@@ -145,16 +155,50 @@
      1.0, -1.0, 0.5, 1.0,       1.0, 1.0,
 ]
 
+class DDSOptions:
+    def __init__(self, colour: QColor = QColor(0, 0, 0, 0), channelMatrix: QMatrix4x4 = QMatrix4x4(), channelOffset: QVector4D = QVector4D()):
+        # QMatrix4x4 with no arguments is the identity matrix, so no channel transformations
+        # declare member variables with None values
+        self.backgroundColour = None
+        self.channelMatrix = None
+        self.channelOffset = None
+        # initialize member variables with error checks
+        self.setBackgroundColour(colour)
+        self.setChannelMatrix(channelMatrix)
+        self.setChannelOffset(channelOffset)
+
+    def setBackgroundColour(self, colour: QColor):
+        if isinstance(colour, QColor) and colour.isValid():
+            self.backgroundColour = colour
+        else:
+            raise TypeError(str(colour) + " is not a valid QColor object.")
+
+    def getBackgroundColour(self) -> QColor:
+        return self.backgroundColour
+
+    def getChannelMatrix(self) -> QMatrix4x4:
+        return self.channelMatrix
+
+    def setChannelMatrix(self, matrix):
+        self.channelMatrix = QMatrix4x4(matrix)
+
+    def getChannelOffset(self) -> QVector4D:
+        return self.channelOffset
+
+    def setChannelOffset(self, vector):
+        self.channelOffset = QVector4D(vector)
 
 
 glVersionProfile = QOpenGLVersionProfile()
 glVersionProfile.setVersion(2, 1)
 
 class DDSWidget(QOpenGLWidget):
-    def __init__(self, ddsFile, debugContext = False, parent = None, f = Qt.WindowFlags()):
+    def __init__(self, ddsFile, ddsOptions = DDSOptions(), debugContext = False, parent = None, f = Qt.WindowFlags()):
         super(DDSWidget, self).__init__(parent, f)
-        
+
         self.ddsFile = ddsFile
+
+        self.ddsOptions = ddsOptions
 
         self.clean = True
 
@@ -166,8 +210,6 @@ def __init__(self, ddsFile, debugContext = False, parent = None, f = Qt.WindowFl
         self.vbo = None
         self.vao = None
 
-        self.backgroundColour = None
-
         if debugContext:
             format = QSurfaceFormat()
             format.setOption(QSurfaceFormat.DebugContext)
@@ -252,9 +294,10 @@ def paintGL(self):
 
         # Draw checkerboard so transparency is obvious
         self.transparecyProgram.bind()
-
-        if self.backgroundColour and self.backgroundColour.isValid():
-            self.transparecyProgram.setUniformValue("backgroundColour", self.backgroundColour)
+
+        backgroundColour = self.ddsOptions.getBackgroundColour()
+        if backgroundColour and backgroundColour.isValid():
+            self.transparecyProgram.setUniformValue("backgroundColour", backgroundColour)
 
         gl.glDrawArrays(gl.GL_TRIANGLES, 0, 6)
 
@@ -264,9 +307,12 @@ def paintGL(self):
 
         if self.texture:
             self.texture.bind()
-        
+
         gl.glEnable(gl.GL_BLEND)
         gl.glBlendFunc(gl.GL_SRC_ALPHA, gl.GL_ONE_MINUS_SRC_ALPHA)
+
+        self.program.setUniformValue("channelMatrix", self.ddsOptions.getChannelMatrix())
+        self.program.setUniformValue("channelOffset", self.ddsOptions.getChannelOffset())
 
         gl.glDrawArrays(gl.GL_TRIANGLES, 0, 6)
 
@@ -291,26 +337,86 @@ def cleanup(self):
             self.doneCurrent()
             self.clean = True
 
-    def setBackgroundColour(self, colour):
-        self.backgroundColour = colour
-
-    def getBackgroundColour(self):
-        return self.backgroundColour
-
     def __tr(self, str):
         return QCoreApplication.translate("DDSWidget", str)
 
 
+class ColourChannels(enum.Enum):
+    RGBA = "Colour and Alpha"
+    RGB = "Colour"
+    A = "Alpha"
+    R = "Red"
+    G = "Green"
+    B = "Blue"
+
+
+class DDSChannelManager:
+    def __init__(self, channels: ColourChannels):
+        self.channels = channels
+
+    def setChannels(self, options: DDSOptions, channels: ColourChannels):
+        self.channels = channels
+        def drawColour(alpha: bool):
+            colorMatrix = QMatrix4x4()
+            colorOffset = QVector4D()
+            if not alpha:
+                colorMatrix[3, 3] = 0
+                colorOffset.setW(1.0)
+            options.setChannelMatrix(colorMatrix)
+            options.setChannelOffset(colorOffset)
+
+        def drawGrayscale(channel: ColourChannels):
+            colorOffset = QVector4D(0, 0, 0, 1)
+            channelVector = [0, 0, 0, 0]
+            if channels == ColourChannels.R:
+                channelVector[0] = 1
+            elif channel == ColourChannels.G:
+                channelVector[1] = 1
+            elif channel == ColourChannels.B:
+                channelVector[2] = 1
+            elif channels == ColourChannels.A:
+                channelVector[3] = 1
+            else:
+                raise ValueError("channel must be a single color channel.")
+            alphaVector = [0, 0, 0, 0]
+            colorMatrix = channelVector * 3 + alphaVector
+            options.setChannelMatrix(colorMatrix)
+            options.setChannelOffset(colorOffset)
+
+        if channels == ColourChannels.RGBA:
+            drawColour(True)
+        elif channels == ColourChannels.RGB:
+            drawColour(False)
+        else:
+            drawGrayscale(channels)
+
+
 class DDSPreview(mobase.IPluginPreview):
 
     def __init__(self):
         super().__init__()
         self.__organizer = None
+        self.options = None
+        self.channelManager = None
 
     def init(self, organizer):
         self.__organizer = organizer
+        savedColour = QColor(self.pluginSetting("background r"), self.pluginSetting("background g"), self.pluginSetting("background b"), self.pluginSetting("background a"))
+        try:
+            savedChannels = ColourChannels[self.pluginSetting("channels")]
+        except KeyError:
+            savedChannels = ColourChannels.RGBA
+        self.options = DDSOptions(savedColour)
+        self.channelManager = DDSChannelManager(savedChannels)
+        self.channelManager.setChannels(self.options, savedChannels)
         return True
 
+    def pluginSetting(self, name):
+        return self.__organizer.pluginSetting(self.name(), name)
+
+    def setPluginSetting(self, name, value):
+        self.__organizer.setPluginSetting(self.name(), name, value)
+
     def name(self):
         return "DDS Preview Plugin"
 
@@ -328,7 +434,8 @@ def settings(self):
                 mobase.PluginSetting("background r", self.__tr("Red channel of background colour"), 0),
                 mobase.PluginSetting("background g", self.__tr("Green channel of background colour"), 0),
                 mobase.PluginSetting("background b", self.__tr("Blue channel of background colour"), 0),
-                mobase.PluginSetting("background a", self.__tr("Alpha channel of background colour"), 0)]
+                mobase.PluginSetting("background a", self.__tr("Alpha channel of background colour"), 0),
+                mobase.PluginSetting("channels", self.__tr("The colour channels that are displayed."), ColourChannels.RGBA.name)]
 
     def supportedExtensions(self):
         return ["dds"]
@@ -342,12 +449,13 @@ def genFilePreview(self, fileName, maxSize):
         # Label grows before button
         layout.setColumnStretch(0, 1)
         layout.addWidget(self.__makeLabel(ddsFile), 1, 0, 1, 1)
-
-        ddsWidget = DDSWidget(ddsFile, self.__organizer.pluginSetting(self.name(), "log gl errors"))
-        layout.addWidget(ddsWidget, 0, 0, 1, 2)
-
-        layout.addWidget(self.__makeColourButton(ddsWidget), 1, 1, 1, 1)
-
+
+        ddsWidget = DDSWidget(ddsFile, self.options, self.__organizer.pluginSetting(self.name(), "log gl errors"))
+        layout.addWidget(ddsWidget, 0, 0, 1, 3)
+
+        layout.addWidget(self.__makeColourButton(ddsWidget), 1, 2, 1, 1)
+        layout.addWidget(self.__makeChannelsButton(ddsWidget), 1, 1, 1, 1)
+
         widget = QWidget()
         widget.setLayout(layout)
         return widget
@@ -363,20 +471,37 @@ def __makeLabel(self, ddsFile):
 
     def __makeColourButton(self, ddsWidget):
         button = QPushButton(self.__tr("Pick background colour"))
-        savedColour = QColor(self.__organizer.pluginSetting(self.name(), "background r"), self.__organizer.pluginSetting(self.name(), "background g"), self.__organizer.pluginSetting(self.name(), "background b"), self.__organizer.pluginSetting(self.name(), "background a"))
-        ddsWidget.setBackgroundColour(savedColour)
-
+
         def pickColour(unused):
-            newColour = QColorDialog.getColor(ddsWidget.getBackgroundColour(), button, "Background colour", QColorDialog.ShowAlphaChannel)
+            newColour = QColorDialog.getColor(self.options.getBackgroundColour(), button, "Background colour", QColorDialog.ShowAlphaChannel)
             if newColour.isValid():
-                ddsWidget.setBackgroundColour(newColour)
-                self.__organizer.setPluginSetting(self.name(), "background r", newColour.red())
-                self.__organizer.setPluginSetting(self.name(), "background g", newColour.green())
-                self.__organizer.setPluginSetting(self.name(), "background b", newColour.blue())
-                self.__organizer.setPluginSetting(self.name(), "background a", newColour.alpha())
+                self.setPluginSetting("background r", newColour.red())
+                self.setPluginSetting("background g", newColour.green())
+                self.setPluginSetting("background b", newColour.blue())
+                self.setPluginSetting("background a", newColour.alpha())
+                self.options.setBackgroundColour(newColour)
+                ddsWidget.update()
 
         button.clicked.connect(pickColour)
         return button
+
+    def __makeChannelsButton(self, ddsWidget):
+        listwidget = QComboBox()
+        channelKeys = [e.name for e in ColourChannels]
+        channelNames = [e.value for e in ColourChannels]
+
+        listwidget.addItems(channelNames)
+        listwidget.setCurrentText(self.channelManager.channels.value)
+        listwidget.setToolTip(self.__tr("Change which channels are displayed."))
+
+        listwidget.showEvent = lambda _: listwidget.setCurrentText(self.channelManager.channels.value)
+        def onChanged(newIndex):
+            self.channelManager.setChannels(self.options, ColourChannels[channelKeys[newIndex]])
+            self.setPluginSetting("channels", self.channelManager.channels.name)
+            ddsWidget.update()
+
+        listwidget.currentIndexChanged.connect(onChanged)
+        return listwidget
 
 def createPlugin():
     return DDSPreview()