Hello
I have a 3D graphics Xamarin project written in C# using Visual Studio 2019 that makes use of OpenTK 1.0. Xamarin is version 5.0.0.1905 and OpenTK is version 4.0.30319.
The app works perfectly well on some Android devices but crashes on others when the DrawArrays method is called with texture applied to the surfaces. As all of the stack traces refer to 'libGLESv2_adreno', I'm guessing the affected devices all have Qualcomm Adreno GPUs.
Here is a typical stack trace:
signal 11 (SIGSEGV), code 1 (SEGV_MAPERR)backtrace:#00 pc 000000000001dc18 /system/lib64/libc.so (memcpy+232)#00 pc 00000000001d0d64 /vendor/lib64/egl/libGLESv2_adreno.so (EsxVertexArrayObject::UpdateInternalVbos(EsxDrawDescriptor const*, unsigned int, EsxAttributeDesc const*)+1644)#00 pc 00000000003374f4 /vendor/lib64/egl/libGLESv2_adreno.so (A5xVertexArrayObject::CalcVfdRegs(EsxDrawDescriptor const*, A5xVfdRegs*, int)+892)#00 pc 000000000034ff54 /vendor/lib64/egl/libGLESv2_adreno.so (A5xContext::ValidateState(EsxDrawDescriptor const*)+1212)#00 pc 000000000033c820 /vendor/lib64/egl/libGLESv2_adreno.so (A5xContext::HwValidateGfxState(EsxDrawDescriptor const*)+16)#00 pc 0000000000115178 /vendor/lib64/egl/libGLESv2_adreno.so (EsxContext::ValidateGfxState(EsxDrawDescriptor const*)+1968)#00 pc 00000000000fd240 /vendor/lib64/egl/libGLESv2_adreno.so (EsxContext::DrawArraysInstanced(EsxPrimType, int, unsigned int, unsigned int)+416)#00 pc 0000000000014f08 <anonymous>
And here are two code snippets that seem to be related to the problem. They have been extracted from the project in question so some variables may require further clarification (please let me know).
Firstly setting up the texture:
using OpenTK.Graphics.ES31;Bitmap b = null;if (modelTexture.ImageBitMap != null){b = BitmapFactory.DecodeByteArray(modelTexture.ImageBitMap, 0, modelTexture.ImageBitMap.Length);int x = Convert.ToInt16(modelTexture.LeftCutoff * b.Width);int y = Convert.ToInt16(modelTexture.TopCutoff * b.Height);int w = b.Width - Convert.ToInt16(modelTexture.RightCutoff * b.Width) - Convert.ToInt16(modelTexture.LeftCutoff * b.Width);int h = b.Height - Convert.ToInt16(modelTexture.BottomCutoff * b.Height) - Convert.ToInt16(modelTexture.TopCutoff * b.Height);b = Bitmap.CreateBitmap(b, x, y, w, h);}int[] textures = new int[1];GL.GenTextures(1, textures);GL.BindTexture(TextureTarget.Texture2D, textures[0]);if (b != null){//allocate memory on the graphics card for the texture.GLUtils.TexImage2D((int)All.Texture2D, 0, b, 0);GL.GenerateMipmap(TextureTarget.Texture2D);GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)All.Nearest);GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)All.NearestMipmapLinear);GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)All.Repeat);GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)All.Repeat);b.Recycle();}GL.BindTexture(TextureTarget.Texture2D, 0);
And secondly, drawing the surfaces:
worldGLView.vertices = vertexLists[bufferIndex].ToArray();worldGLView.texture_coordinates = textureVertexLists[bufferIndex].ToArray();unsafe{fixed (Vector4* pvertices = worldGLView.vertices){// Prepare the triangle coordinate dataGL.VertexAttribPointer(worldGLView.tShaderProgram.mPositionHandle, Vector4.SizeInBytes / 4, VertexAttribPointerType.Float, false, 0, new IntPtr(pvertices));}fixed (Vector2* ptexturecoordinates = worldGLView.texture_coordinates){// Prepare the triangle texture dataGL.VertexAttribPointer(worldGLView.tShaderProgram.mTextureCoordinatesHandle, Vector2.SizeInBytes / 4, VertexAttribPointerType.Float, false, 0, new IntPtr(ptexturecoordinates));}}GL.DrawArrays(BeginMode.Triangles, 0, worldGLView.vertices.Length);
Can anyone suggest what might be causing the problem and how I can fix it?
Please let me know if more information is required.
Thanks in advance.