Fix MSAA texture creation logic

src/modules/graphics/opengl/Graphics.cpp

@@ -1373,7 +1373,7 @@ void Graphics::initCapabilities()
 	capabilities.limits[LIMIT_VOLUME_TEXTURE_SIZE] = gl.getMax3DTextureSize();
 	capabilities.limits[LIMIT_CUBE_TEXTURE_SIZE] = gl.getMaxCubeTextureSize();
 	capabilities.limits[LIMIT_RENDER_TARGETS] = gl.getMaxRenderTargets();
-	capabilities.limits[LIMIT_TEXTURE_MSAA] = gl.getMaxRenderbufferSamples();
+	capabilities.limits[LIMIT_TEXTURE_MSAA] = gl.getMaxSamples();
 	capabilities.limits[LIMIT_ANISOTROPY] = gl.getMaxAnisotropy();
 	static_assert(LIMIT_MAX_ENUM == 8, "Graphics::initCapabilities must be updated when adding a new system limit!");
 

src/modules/graphics/opengl/OpenGL.cpp

@@ -102,7 +102,7 @@ OpenGL::OpenGL()
 	, maxCubeTextureSize(0)
 	, maxTextureArrayLayers(0)
 	, maxRenderTargets(1)
-	, maxRenderbufferSamples(0)
+	, maxSamples(1)
 	, maxTextureUnits(1)
 	, maxPointSize(1)
 	, coreProfile(false)
@@ -474,10 +474,10 @@ void OpenGL::initMaxValues()
 		|| GLAD_EXT_framebuffer_multisample || GLAD_APPLE_framebuffer_multisample
 		|| GLAD_ANGLE_framebuffer_multisample)
 	{
-		glGetIntegerv(GL_MAX_SAMPLES, &maxRenderbufferSamples);
+		glGetIntegerv(GL_MAX_SAMPLES, &maxSamples);
 	}
 	else
-		maxRenderbufferSamples = 0;
+		maxSamples = 1;
 
 	glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &maxTextureUnits);
 
@@ -1358,9 +1358,9 @@ int OpenGL::getMaxRenderTargets() const
 	return std::min(maxRenderTargets, MAX_COLOR_RENDER_TARGETS);
 }
 
-int OpenGL::getMaxRenderbufferSamples() const
+int OpenGL::getMaxSamples() const
 {
-	return maxRenderbufferSamples;
+	return maxSamples;
 }
 
 int OpenGL::getMaxTextureUnits() const

src/modules/graphics/opengl/OpenGL.h

@@ -363,9 +363,9 @@ public:
 	int getMaxRenderTargets() const;
 
 	/**
-	 * Returns the maximum supported number of MSAA samples for renderbuffers.
+	 * Returns the maximum supported number of MSAA sampless.
 	 **/
-	int getMaxRenderbufferSamples() const;
+	int getMaxSamples() const;
 
 	/**
 	 * Returns the maximum number of accessible texture units.
@@ -436,7 +436,7 @@ private:
 	int maxCubeTextureSize;
 	int maxTextureArrayLayers;
 	int maxRenderTargets;
-	int maxRenderbufferSamples;
+	int maxSamples;
 	int maxTextureUnits;
 	float maxPointSize;
 

src/modules/graphics/opengl/Texture.cpp

@@ -280,10 +280,7 @@ bool Texture::createTexture()
 			}
 
 			if (mipsize > 0)
-			{
-				GLenum gltarget = OpenGL::getGLTextureType(texType);
-				glCompressedTexImage3D(gltarget, mip, fmt.internalformat, w, h, d, 0, mipsize, nullptr);
-			}
+				glCompressedTexImage3D(gltype, mip, fmt.internalformat, w, h, d, 0, mipsize, nullptr);
 		}
 
 		for (int slice = 0; slice < slicecount; slice++)
@@ -352,10 +349,7 @@ bool Texture::loadVolatile()
 		samplerState.mipmapFilter = SamplerState::MIPMAP_FILTER_NONE;
 	}
 
-	// getMaxRenderbufferSamples will be 0 on systems that don't support
-	// multisampled renderbuffers / don't export FBO multisample extensions.
-	actualSamples = std::min(getRequestedMSAA(), gl.getMaxRenderbufferSamples());
-	actualSamples = std::max(actualSamples, 1);
+	actualSamples = std::max(1, std::min(getRequestedMSAA(), gl.getMaxSamples()));
 
 	while (glGetError() != GL_NO_ERROR); // Clear errors.
 
@@ -363,7 +357,7 @@ bool Texture::loadVolatile()
 	{
 		if (isReadable())
 			createTexture();
-		if (!isReadable() && actualSamples > 1)
+		if (!isReadable() || actualSamples > 1)
 			createRenderbuffer();
 
 		GLenum glerr = glGetError();