I workd with OPENGL.
Code is too long.
System:windowsxp,
Treiber-Paketversion 8.723-100406a-098786C
Anbieter ATI Technologies Inc.
2D-Treiberversion 6.14.10.7070
Direct3D-Version 6.14.10.0743
OpenGL-Version 6.14.10.9756
Catalyst™ Control Center-Version 2010.0406.2133.36843
AIW/VIVO WDM-Treiberversion 6.14.10.6238
AIW/VIVO WDM-SP-Treiberversion 6.14.10.6238
If (gTexture.Handle = 0) Then Begin Assert (GL_EXT_texture3D, 'Graphic card does not support 3D textures.'); //Use PROXY to see if video card can support a texture... //http://www.opengl.org/resources/faq/technical/texture.htm //glTexImage3D(GL_PROXY_TEXTURE_2D, level, internalFormat, width, height, border, format, type, NULL); //Note the pixels parameter is NULL, because OpenGL doesn't load texel data when the target parameter is GL_PROXY_TEXTURE_2D. Instead, OpenGL merely considers whether it can accommodate a texture of the specified size and description. If the specified texture can't be accommodated, the width and height texture values will be set to zero. After making a texture proxy call, you'll want to query these values as follows: glTexImage3D (GL_PROXY_TEXTURE_3D, 0, GL_RGBA8, gTexture3D.FiltDim[1], gTexture3D.FiltDim[2], gTexture3D.FiltDim[3], 0, gTexture3D.DataType, GL_UNSIGNED_BYTE, nil); glGetTexLevelParameteriv(GL_PROXY_TEXTURE_3D, 0, GL_TEXTURE_WIDTH, @i); if i < 1 then begin showmessage('Your video card is unable to load an image that is this large.'); exit; end; //end of PROXY If (gTexture.Handle = 0) then gTexture.AllocateHandle; glBindTexture (GL_TEXTURE_3D, gTexture.Handle); glTexParameterf (GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP); glTexParameterf (GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP); glTexParameterf (GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP); glTexParameteri (GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri (GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexEnvf (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE); //OSX glTexImage3D not glTexImage3DEXT {$IFDEF Darwin} glTexImage3D (GL_TEXTURE_3D, 0, GL_RGBA8, gTexture3D.FiltDim[1], gTexture3D.FiltDim[2], gTexture3D.FiltDim[3], 0, gTexture3D.DataType, GL_UNSIGNED_BYTE, PChar(gTexture3D.FiltImg)); {$ELSE} glTexImage3DExt (GL_TEXTURE_3D, 0, GL_RGBA8, gTexture3D.FiltDim[1], gTexture3D.FiltDim[2], gTexture3D.FiltDim[3], 0, gTexture3D.DataType, GL_UNSIGNED_BYTE, PChar(gTexture3D.FiltImg)); {$ENDIF} //glTexImage3DEXT (GL_TEXTURE_3D, 0, GL_RGBA8, gTexture3D.FiltDim[1], gTexture3D.FiltDim[2], gTexture3D.FiltDim[3], 0, gTexture3D.DataType, GL_UNSIGNED_BYTE, PChar(gTexture3D.FiltImg)); //glTexImage3DEXT (GL_TEXTURE_3D, 0, GL_RGBA8, gTexture3D.Dim[1], gTexture3D.Dim[2], gTexture3D.Dim[3], 0, gTexture3D.Data_Type, GL_UNSIGNED_BYTE, PChar (gTexture3D.OData)); End; //new texture //exit; If M_Refresh = TRUE Then Begin //if texture changed due to loading new image, adjusting surface threshold, changing cutout M_Refresh := FALSE; Calculate_Transfer_Function; //glTexImage3D (GL_TEXTURE_3D, 0, GL_RGBA8, gTexture3D.Dim[1], gTexture3D.Dim[2], gTexture3D.Dim[3], 0, gTexture3D.Data_Type, GL_UNSIGNED_BYTE, PChar (gTexture3D.OData)); //glTexImage3DEXT (GL_TEXTURE_3D, 0, GL_RGBA8, gTexture3D.FiltDim[1], gTexture3D.FiltDim[2], gTexture3D.FiltDim[3], 0, gTexture3D.DataType, GL_UNSIGNED_BYTE, PChar(gTexture3D.FiltImg)); //OSX only supports glTexSubImage3D not glTexSubImage3DExt //Intel cards on Windows only support glTexSubImage3D not glTexSubImage3DExt {$IFDEF FPC} {$IFDEF Darwin} glTexSubImage3D (GL_TEXTURE_3D, 0, 0, 0, 0, gTexture3D.FiltDim[1], gTexture3D.FiltDim[2], gTexture3D.FiltDim[3], gTexture3D.DataType, GL_UNSIGNED_BYTE, PChar (gTexture3D.FiltImg)); {$ELSE} //The stable release of Lazarus GLScene for Windows only includes the Ext version... glTexSubImage3DExt (GL_TEXTURE_3D, 0, 0, 0, 0, gTexture3D.FiltDim[1], gTexture3D.FiltDim[2], gTexture3D.FiltDim[3], gTexture3D.DataType, GL_UNSIGNED_BYTE, PChar (gTexture3D.FiltImg)); {$ENDIF} {$ELSE} //not FPC - Intel cards on Windows prefer glTexSubImage3D over glTexSubImage3DExt glTexSubImage3D (GL_TEXTURE_3D, 0, 0, 0, 0, gTexture3D.FiltDim[1], gTexture3D.FiltDim[2], gTexture3D.FiltDim[3], gTexture3D.DataType, GL_UNSIGNED_BYTE, PChar (gTexture3D.FiltImg)); {$ENDIF} End; //if M_refresh // reset matrix - glLoadIdentity(); glPushAttrib (GL_ENABLE_BIT); glPushMatrix; glEnable (GL_BLEND); //glShadeModel(GL_SMOOTH); //integration can select brightest voxel that the ray traverses [MIP] // or the data can be integrated based on alpha level [trnanslucent slices] if MIPMenu.checked then glBlendEquationEXT(GL_MAX_EXT) else glBlendEquationEXT(GL_FUNC_ADD_EXT); glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glDisable (GL_CULL_FACE); glDisable (GL_LIGHTING); //glEnable (GL_LIGHTING); glTexGenf (GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR); glTexGenf (GL_T, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR); glTexGenf (GL_R, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR); SetVector (v, XVector, 0.5); glTexGenfv (GL_S, GL_OBJECT_PLANE, @v); SetVector (v, YVector, 0.5); glTexGenfv (GL_T, GL_OBJECT_PLANE, @v); SetVector (v, ZVector, 0.5); glTexGenfv (GL_R, GL_OBJECT_PLANE, @v); glEnable (GL_TEXTURE_GEN_S); glEnable (GL_TEXTURE_GEN_T); glEnable (GL_TEXTURE_GEN_R); //without clip planes, voxels on the edges bleed into the periphery... glClipPlane(GL_CLIP_PLANE0, @clip0); glClipPlane(GL_CLIP_PLANE1, @clip1); glClipPlane(GL_CLIP_PLANE2, @clip2); glClipPlane(GL_CLIP_PLANE3, @clip3); glClipPlane(GL_CLIP_PLANE4, @clip4); glClipPlane(GL_CLIP_PLANE5, @clip5); glEnable(GL_CLIP_PLANE0); glEnable(GL_CLIP_PLANE1); glEnable(GL_CLIP_PLANE2); glEnable(GL_CLIP_PLANE3); glEnable(GL_CLIP_PLANE4); glEnable(GL_CLIP_PLANE5); //finally, draw object glBindTexture (GL_TEXTURE_3D, gTexture.Handle); if gPrefs.RenderQuality = kNORender then begin //draw slice sections instead of rendering... //glColor4f (1, 1, 1,1); //glBlendFunc (GL_ONE,GL_ZERO{GL_DST_COLOR, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA}); glBlendFunc (GL_ONE,GL_ZERO); glEnable (GL_TEXTURE_3D); // glMatrixMode(GL_MODELVIEW); z := 0; //slice glBegin (GL_QUADS); //X constant : sagittal glVertex3f (z, 1, 1); glVertex3f (z, -1, 1); glVertex3f (z,-1,-1); glVertex3f (z, 1, -1); //Y constant : coronal glVertex3f (1, z, 1); glVertex3f ( -1,z, 1); glVertex3f (-1,z,-1); glVertex3f (1,z, -1); //Z constant : axial glVertex3f (1, 1, z); glVertex3f (-1, 1, z); glVertex3f (-1,-1, z); glVertex3f (1, -1, z); glEnd; end else begin //not 2D planes ... next 3D rendering depthplanes := round(sqrt(sqr(gTexture3D.FiltDim[1])+sqr(gTexture3D.FiltDim[2])+sqr(gTexture3D.FiltDim[3]))); if gPrefs.RenderQuality = kFastRender then depthplanes := depthplanes div 2;//round(sqrt(sqr(gTexture3D.FiltDim[1])+sqr(gTexture3D.FiltDim[2])+sqr(gTexture3D.FiltDim[3]))); if depthplanes < 1 then depthplanes := 1; glEnable (GL_TEXTURE_3D); glGetFloatv (GL_MODELVIEW_MATRIX, @mat); vx [0] := mat [0] [0]; vy [0] := mat [0] [1]; vz [0] := mat [0] [2]; vx [1] := mat [1] [0]; vy [1] := mat [1] [1]; vz [1] := mat [1] [2]; vx [2] := mat [2] [0]; vy [2] := mat [2] [1]; vz [2] := mat [2] [2]; ScaleVector (vx, DIAGONAL_LENGTH * 0.5 / VectorLength (vx)); ScaleVector (vy, DIAGONAL_LENGTH * 0.5 / VectorLength (vy)); ScaleVector (vz, DIAGONAL_LENGTH * 0.5 / VectorLength (vz)); step := DIAGONAL_LENGTH / depthplanes; z := -DIAGONAL_LENGTH / 2; glBegin (GL_QUADS); glColor4f (gObjRed, gObjGreen, gObjBlue, 1.0); For i := 0 To depthplanes - 1 Do Begin //next line commented out...surface normals not used for volume rendering //glNormal3f (-GLCamera.AbsoluteVectorToTarget [0], -GLCamera.AbsoluteVectorToTarget [1], -GLCamera.AbsoluteVectorToTarget [2]); glVertex3f (vx [0] + vy [0] + vz [0] * z, vx [1] + vy [1] + vz [1] * z, vx [2] + vy [2] + vz [2] * z); glVertex3f (-vx [0] + vy [0] + vz [0] * z, -vx [1] + vy [1] + vz [1] * z, -vx [2] + vy [2] + vz [2] * z); glVertex3f (-vx [0] - vy [0] + vz [0] * z, -vx [1] - vy [1] + vz [1] * z, -vx [2] - vy [2] + vz [2] * z); glVertex3f (vx [0] - vy [0] + vz [0] * z, vx [1] - vy [1] + vz [1] * z, vx [2] - vy [2] + vz [2] * z); z := z + step; End; glEnd; end; //Rendering if MIPMenu.checked then //return to normal, otherwise overlay text appears odd.. glBlendEquationEXT(GL_FUNC_ADD_EXT); glPopMatrix; glPopAttrib;
