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Blender
Module BGL

Module BGL

source code

The Blender.BGL submodule (the OpenGL wrapper).

New: some GLU functions: gluLookAt, etc.

The Blender.BGL submodule

This module wraps OpenGL constants and functions, making them available from within Blender Python.

The complete list can be retrieved from the module itself, by listing its contents: dir(Blender.BGL). A simple search on the net can point to more than enough material to teach OpenGL programming, from books to many collections of tutorials.

The "red book": "OpenGL Programming Guide: The Official Guide to Learning OpenGL" and the online NeHe tutorials are two of the best resources.

Example: 
 import Blender
 from Blender.BGL import *
 from Blender import Draw
 R = G = B = 0
 A = 1
 title = "Testing BGL  + Draw"
 instructions = "Use mouse buttons or wheel to change the background color."
 quitting = " Press ESC or q to quit."
 len1 = Draw.GetStringWidth(title)
 len2 = Draw.GetStringWidth(instructions + quitting)
 #
 def show_win():
   glClearColor(R,G,B,A)                # define color used to clear buffers 
   glClear(GL_COLOR_BUFFER_BIT)         # use it to clear the color buffer
   glColor3f(0.35,0.18,0.92)            # define default color
   glBegin(GL_POLYGON)                  # begin a vertex data list
   glVertex2i(165, 158)
   glVertex2i(252, 55)
   glVertex2i(104, 128)
   glEnd()
   glColor3f(0.4,0.4,0.4)               # change default color
   glRecti(40, 96, 60+len1, 113)
   glColor3f(1,1,1)
   glRasterPos2i(50,100)                # move cursor to x = 50, y = 100
   Draw.Text(title)                     # draw this text there
   glRasterPos2i(350,40)                # move cursor again
   Draw.Text(instructions + quitting)   # draw another msg
   glBegin(GL_LINE_LOOP)                # begin a vertex-data list
   glVertex2i(46,92)
   glVertex2i(120,92)
   glVertex2i(120,115)
   glVertex2i(46,115)
   glEnd()                              # close this list
 #
 def ev(evt, val):                      # event callback for Draw.Register()
   global R,G,B,A                       # ... it handles input events
   if evt == Draw.ESCKEY or evt == Draw.QKEY:
     Draw.Exit()                        # this quits the script
   elif not val: return
   elif evt == Draw.LEFTMOUSE: R = 1 - R
   elif evt == Draw.MIDDLEMOUSE: G = 1 - G
   elif evt == Draw.RIGHTMOUSE: B = 1 - B
   elif evt == Draw.WHEELUPMOUSE:
     R += 0.1
     if R > 1: R = 1
   elif evt == Draw.WHEELDOWNMOUSE:
     R -= 0.1
     if R < 0: R = 0
   else:
     return                             # don't redraw if nothing changed
   Draw.Redraw(1)                       # make changes visible.
 #
 Draw.Register(show_win, ev, None)      # start the main loop


Note: you can use the Image module and Image.Image BPy object to load and set textures. See Image.Image.glLoad and Image.Image.glFree, for example.

See Also:
www.opengl.org, nehe.gamedev.net
Classes
  Buffer
The Buffer object is simply a block of memory that is delineated and initialized by the user.
Functions
 
glAccum(op, value)
Operate on the accumulation buffer		 source code
 
glAlphaFunc(func, ref)
Specify the alpha test function		 source code
 
glAreTexturesResident(n, textures, residences)
Determine if textures are loaded in texture memory		 source code
 
glBegin(mode)
Delimit the vertices of a primitive or a group of like primatives		 source code
 
glBindTexture(target, texture)
Bind a named texture to a texturing target		 source code
 
glBitmap(width, height, xorig, yorig, xmove, ymove, bitmap)
Draw a bitmap		 source code
 
glBlendFunc(sfactor, dfactor)
Specify pixel arithmetic		 source code
 
glCallList(list)
Execute a display list		 source code
 
glCallLists(n, type, lists)
Execute a list of display lists		 source code
 
glClear(mask)
Clear buffers to preset values		 source code
 
glClearAccum(red, green, blue, alpha)
Specify clear values for the accumulation buffer		 source code
 
glClearColor(red, green, blue, alpha)
Specify clear values for the color buffers		 source code
 
glClearDepth(depth)
Specify the clear value for the depth buffer		 source code
 
glClearIndex(c)
Specify the clear value for the color index buffers		 source code
 
glClearStencil(s)
Specify the clear value for the stencil buffer		 source code
 
glClipPlane(plane, equation)
Specify a plane against which all geometry is clipped		 source code
 
glColor(red, green, blue, alpha)
glColor3b, glColor3d, glColor3f, glColor3i, glColor3s, glColor3ub, glColor3ui, glColor3us, glColor4b, glColor4d, glColor4f, glColor4i, glColor4s, glColor4ub, glColor4ui, glColor4us, glColor3bv, glColor3dv, glColor3fv, glColor3iv, glColor3sv, glColor3ubv, glColor3uiv, glColor3usv, glColor4bv, glColor4dv, glColor4fv, glColor4iv, glColor4sv, glColor4ubv, glColor4uiv, glColor4usv		 source code
 
glColorMask(red, green, blue, alpha)
Enable and disable writing of frame buffer color components		 source code
 
glColorMaterial(face, mode)
Cause a material color to track the current color		 source code
 
glCopyPixels(x, y, width, height, type)
Copy pixels in the frame buffer		 source code
 
glCullFace(mode)
Specify whether front- or back-facing facets can be culled		 source code
 
glDeleteLists(list, range)
Delete a contiguous group of display lists		 source code
 
glDeleteTextures(n, textures)
Delete named textures		 source code
 
glDepthFunc(func)
Specify the value used for depth buffer comparisons		 source code
 
glDepthMask(flag)
Enable or disable writing into the depth buffer		 source code
 
glDepthRange(zNear, zFar)
Specify mapping of depth values from normalized device coordinates to window coordinates		 source code
 
glDisable(cap)
Disable server-side GL capabilities		 source code
 
glDrawBuffer(mode)
Specify which color buffers are to be drawn into		 source code
 
glDrawPixels(width, height, format, type, pixels)
Write a block of pixels to the frame buffer		 source code
 
glEdgeFlag(flag)
glEdgeFlag, glEdgeFlagv		 source code
 
glEnable(cap)
Enable server-side GL capabilities		 source code
 
glEnd()
Delimit the vertices of a primitive or group of like primitives		 source code
 
glEndList()
Create or replace a display list		 source code
 
glEvalCoord(u, v)
glEvalCoord1d, glEvalCoord1f, glEvalCoord2d, glEvalCoord2f, glEvalCoord1dv, glEvalCoord1fv, glEvalCoord2dv, glEvalCoord2fv		 source code
 
glEvalMesh(mode, i1, i2)
glEvalMesh1 or glEvalMesh2		 source code
 
glEvalPoint(i, j)
glEvalPoint1 and glEvalPoint2		 source code
 
glFeedbackBuffer(size, type, buffer)
Controls feedback mode		 source code
 
glFinish()
Block until all GL execution is complete		 source code
 
glFlush()
Force Execution of GL commands in finite time		 source code
 
glFog(pname, param)
glFogf, glFogi, glFogfv, glFogiv		 source code
 
glFrontFace(mode)
Define front- and back-facing polygons		 source code
 
glFrustum(left, right, bottom, top, zNear, zFar)
Multiply the current matrix by a perspective matrix		 source code
 
glGenLists(range)
Generate a contiguous set of empty display lists		 source code
 
glGenTextures(n, textures)
Generate texture names		 source code
 
glGet(pname, param)
glGetBooleanv, glGetfloatv, glGetFloatv, glGetIntegerv		 source code
 
glGetClipPlane(plane, equation)
Return the coefficients of the specified clipping plane		 source code
 
glGetError()
Return error information		 source code
 
glGetLight(light, pname, params)
glGetLightfv and glGetLightiv		 source code
 
glGetMap(target, query, v)
glGetMapdv, glGetMapfv, glGetMapiv		 source code
 
glGetMaterial(face, pname, params)
glGetMaterialfv, glGetMaterialiv		 source code
 
glGetPixelMap(map, values)
glGetPixelMapfv, glGetPixelMapuiv, glGetPixelMapusv		 source code
 
glGetPolygonStipple(mask)
Return the polygon stipple pattern		 source code
 
glGetString(name)
Return a string describing the current GL connection		 source code
 
glGetTexEnv(target, pname, params)
glGetTexEnvfv, glGetTexEnviv		 source code
 
glGetTexGen(coord, pname, params)
glGetTexGendv, glGetTexGenfv, glGetTexGeniv		 source code
 
glGetTexImage(target, level, format, type, pixels)
Return a texture image		 source code
 
glGetTexLevelParameter(target, level, pname, params)
glGetTexLevelParameterfv, glGetTexLevelParameteriv		 source code
 
glGetTexParameter(target, pname, params)
glGetTexParameterfv, glGetTexParameteriv		 source code
 
glHint(target, mode)
Specify implementation-specific hints		 source code
 
glIndex(c)
glIndexd, glIndexf, glIndexi, glIndexs, glIndexdv, glIndexfv, glIndexiv, glIndexsv		 source code
 
glInitNames()
Initialize the name stack		 source code
 
glIsEnabled(cap)
Test whether a capability is enabled		 source code
 
glIsList(list)
Determine if a name corresponds to a display-list		 source code
 
glIsTexture(texture)
Determine if a name corresponds to a texture		 source code
 
glLight(light, pname, param)
glLightf,glLighti, glLightfv, glLightiv		 source code
 
glLightModel(pname, param)
glLightModelf, glLightModeli, glLightModelfv, glLightModeliv		 source code
 
glLineStipple(factor, pattern)
Specify the line stipple pattern		 source code
 
glLineWidth(width)
Specify the width of rasterized lines.		 source code
 
glListBase(base)
Set the display-list base for glCallLists		 source code
 
glLoadIdentity()
Replace the current matrix with the identity matrix		 source code
 
glLoadMatrix(m)
glLoadMatrixd, glLoadMatixf		 source code
 
glLoadName(name)
Load a name onto the name stack.		 source code
 
glLogicOp(opcode)
Specify a logical pixel operation for color index rendering		 source code
 
glMap1(target, u1, u2, stride, order, points)
glMap1d, glMap1f		 source code
 
glMap2(target, u1, u2, ustride, uorder, v1, v2, vstride, vorder, points)
glMap2d, glMap2f		 source code
 
glMapGrid(un, u1, u2, vn, v1, v2)
glMapGrid1d, glMapGrid1f, glMapGrid2d, glMapGrid2f		 source code
 
glMaterial(face, pname, params)
Specify material parameters for the lighting model.		 source code
 
glMatrixMode(mode)
Specify which matrix is the current matrix.		 source code
 
glMultMatrix(m)
glMultMatrixd, glMultMatrixf		 source code
 
glNewList(list, mode)
Create or replace a display list		 source code
 
glNormal3(nx, ny, nz, v)
Normal3b, Normal3bv, Normal3d, Normal3dv, Normal3f, Normal3fv, Normal3i, Normal3iv, Normal3s, Normal3sv		 source code
 
glOrtho(left, right, bottom, top, zNear, zFar)
Multiply the current matrix with an orthographic matrix		 source code
 
glPassThrough(token)
Place a marker in the feedback buffer		 source code
 
glPixelMap(map, mapsize, values)
glPixelMapfv, glPixelMapuiv, glPixelMapusv		 source code
 
glPixelStore(pname, param)
glPixelStoref, glPixelStorei		 source code
 
glPixelTransfer(pname, param)
glPixelTransferf, glPixelTransferi		 source code
 
glPixelZoom(xfactor, yfactor)
Specify the pixel zoom factors		 source code
 
glPointSize(size)
Specify the diameter of rasterized points		 source code
 
glPolygonMode(face, mode)
Select a polygon rasterization mode		 source code
 
glPolygonOffset(factor, units)
Set the scale and units used to calculate depth values		 source code
 
glPolygonStipple(mask)
Set the polygon stippling pattern		 source code
 
glPopAttrib()
Pop the server attribute stack		 source code
 
glPopClientAttrib()
Pop the client attribute stack		 source code
 
glPopMatrix()
Pop the current matrix stack		 source code
 
glPopName()
Pop the name stack		 source code
 
glPrioritizeTextures(n, textures, priorities)
Set texture residence priority		 source code
 
glPushAttrib(mask)
Push the server attribute stack		 source code
 
glPushClientAttrib(mask)
Push the client attribute stack		 source code
 
glPushMatrix()
Push the current matrix stack		 source code
 
glPushName(name)
Push the name stack		 source code
 
glRasterPos(x, y, z, w)
glRasterPos2d, glRasterPos2f, glRasterPos2i, glRasterPos2s, glRasterPos3d, glRasterPos3f, glRasterPos3i, glRasterPos3s, glRasterPos4d, glRasterPos4f, glRasterPos4i, glRasterPos4s, glRasterPos2dv, glRasterPos2fv, glRasterPos2iv, glRasterPos2sv, glRasterPos3dv, glRasterPos3fv, glRasterPos3iv, glRasterPos3sv, glRasterPos4dv, glRasterPos4fv, glRasterPos4iv, glRasterPos4sv		 source code
 
glReadBuffer(mode)
Select a color buffer source for pixels.		 source code
 
glReadPixels(x, y, width, height, format, type, pixels)
Read a block of pixels from the frame buffer		 source code
 
glRect(x1, y1, x2, y2, v1, v2)
glRectd, glRectf, glRecti, glRects, glRectdv, glRectfv, glRectiv, glRectsv		 source code
 
glRenderMode(mode)
Set rasterization mode		 source code
 
glRotate(angle, x, y, z)
glRotated, glRotatef		 source code
 
glScale(x, y, z)
glScaled, glScalef		 source code
 
glScissor(x, y, width, height)
Define the scissor box		 source code
 
glSelectBuffer(size, buffer)
Establish a buffer for selection mode values		 source code
 
glShadeModel(mode)
Select flat or smooth shading		 source code
 
glStencilFuc(func, ref, mask)
Set function and reference value for stencil testing		 source code
 
glStencilMask(mask)
Control the writing of individual bits in the stencil planes		 source code
 
glStencilOp(fail, zfail, zpass)
Set stencil test actions		 source code
 
glTexCoord(s, t, r, q, v)
glTexCoord1d, glTexCoord1f, glTexCoord1i, glTexCoord1s, glTexCoord2d, glTexCoord2f, glTexCoord2i, glTexCoord2s, glTexCoord3d, glTexCoord3f, glTexCoord3i, glTexCoord3s, glTexCoord4d, glTexCoord4f, glTexCoord4i, glTexCoord4s, glTexCoord1dv, glTexCoord1fv, glTexCoord1iv, glTexCoord1sv, glTexCoord2dv, glTexCoord2fv, glTexCoord2iv, glTexCoord2sv, glTexCoord3dv, glTexCoord3fv, glTexCoord3iv, glTexCoord3sv, glTexCoord4dv, glTexCoord4fv, glTexCoord4iv, glTexCoord4sv		 source code
 
glTexEnv(target, pname, param)
glTextEnvf, glTextEnvi, glTextEnvfv, glTextEnviv		 source code
 
glTexGen(coord, pname, param)
glTexGend, glTexGenf, glTexGeni, glTexGendv, glTexGenfv, glTexGeniv		 source code
 
glTexImage1D(target, level, internalformat, width, border, format, type, pixels)
Specify a one-dimensional texture image		 source code
 
glTexImage2D(target, level, internalformat, width, height, border, format, type, pixels)
Specify a two-dimensional texture image		 source code
 
glTexParameter(target, pname, param)
glTexParameterf, glTexParameteri, glTexParameterfv, glTexParameteriv		 source code
 
glTranslate(x, y, z)
glTranslatef, glTranslated		 source code
 
glVertex(x, y, z, w, v)
glVertex2d, glVertex2f, glVertex2i, glVertex2s, glVertex3d, glVertex3f, glVertex3i, glVertex3s, glVertex4d, glVertex4f, glVertex4i, glVertex4s, glVertex2dv, glVertex2fv, glVertex2iv, glVertex2sv, glVertex3dv, glVertex3fv, glVertex3iv, glVertex3sv, glVertex4dv, glVertex4fv, glVertex4iv, glVertex4sv		 source code
 
glViewport(x, y, width, height)
Set the viewport		 source code
 
gluPerspective(fovY, aspect, zNear, zFar)
Set up a perspective projection matrix.		 source code
 
gluLookAt(eyex, eyey, eyez, centerx, centery, centerz, upx, upy, upz)
Define a viewing transformation		 source code
 
gluOrtho2D(left, right, bottom, top)
Define a 2-D orthographic projection matrix		 source code
 
gluPickMatrix(x, y, width, height, viewport)
Define a picking region		 source code
 
gluProject(objx, objy, objz, modelMatrix, projMatrix, viewport, winx, winy, winz)
Map object coordinates to window coordinates.		 source code
 
gluUnProject(winx, winy, winz, modelMatrix, projMatrix, viewport, objx, objy, objz)
Map object coordinates to window coordinates.		 source code
Function Details

glAccum(op, value)

source code 
Operate on the accumulation buffer
Parameters:
  • op (Enumerated constant) - The accumulation buffer operation.
  • value (float) - a value used in the accumulation buffer operation.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/accum.html

glAlphaFunc(func, ref)

source code 
Specify the alpha test function
Parameters:
  • func (Enumerated constant) - Specifies the alpha comparison function.
  • ref (float) - The reference value that incoming alpha values are compared to. Clamped between 0 and 1.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/alphafunc.html

glAreTexturesResident(n, textures, residences)

source code 
Determine if textures are loaded in texture memory
Parameters:
  • n (int) - Specifies the number of textures to be queried.
  • textures (Buffer object type GL_INT) - Specifies an array containing the names of the textures to be queried
  • residences (Buffer object type GL_INT(boolean)) - An array in which the texture residence status in returned.The residence status of a texture named by an element of textures is returned in the corresponding element of residences.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/aretexturesresident.html

glBegin(mode)

source code 
Delimit the vertices of a primitive or a group of like primatives
Parameters:
  • mode (Enumerated constant) - Specifies the primitive that will be create from vertices between glBegin and glEnd.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/begin.html

glBindTexture(target, texture)

source code 
Bind a named texture to a texturing target
Parameters:
  • target (Enumerated constant) - Specifies the target to which the texture is bound.
  • texture (unsigned int) - Specifies the name of a texture.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/bindtexture.html

glBitmap(width, height, xorig, yorig, xmove, ymove, bitmap)

source code 
Draw a bitmap
Parameters:
  • width, height - Specify the pixel width and height of the bitmap image.
  • xorig, yorig - Specify the location of the origin in the bitmap image. The origin is measured from the lower left corner of the bitmap, with right and up being the positive axes.
  • xmove, ymove - Specify the x and y offsets to be added to the current raster position after the bitmap is drawn.
  • bitmap (Buffer object type GL_BYTE) - Specifies the address of the bitmap image.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/bitmap.html

glBlendFunc(sfactor, dfactor)

source code 
Specify pixel arithmetic
Parameters:
  • sfactor (Enumerated constant) - Specifies how the red, green, blue, and alpha source blending factors are computed.
  • dfactor (Enumerated constant) - Specifies how the red, green, blue, and alpha destination blending factors are computed.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/blendfunc.html

glCallList(list)

source code 
Execute a display list
Parameters:
  • list (unsigned int) - Specifies the integer name of the display list to be executed.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/calllist.html

glCallLists(n, type, lists)

source code 
Execute a list of display lists
Parameters:
  • n (int) - Specifies the number of display lists to be executed.
  • type (Enumerated constant) - Specifies the type of values in lists.
  • lists (Buffer object) - Specifies the address of an array of name offsets in the display list. The pointer type is void because the offsets can be bytes, shorts, ints, or floats, depending on the value of type.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/calllists.html

glClear(mask)

source code 
Clear buffers to preset values
Parameters:
  • mask (Enumerated constant(s)) - Bitwise OR of masks that indicate the buffers to be cleared.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/clear.html

glClearAccum(red, green, blue, alpha)

source code 
Specify clear values for the accumulation buffer
Parameters:
  • red, green, blue, alpha - Specify the red, green, blue, and alpha values used when the accumulation buffer is cleared. The initial values are all 0.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/clearaccum.html

glClearColor(red, green, blue, alpha)

source code 
Specify clear values for the color buffers
Parameters:
  • red, green, blue, alpha - Specify the red, green, blue, and alpha values used when the color buffers are cleared. The initial values are all 0.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/clearcolor.html

glClearDepth(depth)

source code 
Specify the clear value for the depth buffer
Parameters:
  • depth (int) - Specifies the depth value used when the depth buffer is cleared. The initial value is 1.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/cleardepth.html

glClearIndex(c)

source code 
Specify the clear value for the color index buffers
Parameters:
  • c (float) - Specifies the index used when the color index buffers are cleared. The initial value is 0.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/clearindex.html

glClearStencil(s)

source code 
Specify the clear value for the stencil buffer
Parameters:
  • s (int) - Specifies the index used when the stencil buffer is cleared. The initial value is 0.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/clearstencil.html

glClipPlane(plane, equation)

source code 
Specify a plane against which all geometry is clipped
Parameters:
  • plane (Enumerated constant) - Specifies which clipping plane is being positioned.
  • equation (Buffer object type GL_FLOAT(double)) - Specifies the address of an array of four double- precision floating-point values. These values are interpreted as a plane equation.

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/clipplane.html

glColor(red, green, blue, alpha)

source code 

glColor3b, glColor3d, glColor3f, glColor3i, glColor3s, glColor3ub, glColor3ui, glColor3us, glColor4b, glColor4d, glColor4f, glColor4i, glColor4s, glColor4ub, glColor4ui, glColor4us, glColor3bv, glColor3dv, glColor3fv, glColor3iv, glColor3sv, glColor3ubv, glColor3uiv, glColor3usv, glColor4bv, glColor4dv, glColor4fv, glColor4iv, glColor4sv, glColor4ubv, glColor4uiv, glColor4usv

Set a new color.
Parameters:
  • red, green, blue - Specify new red, green, and blue values for the current color.
  • alpha - Specifies a new alpha value for the current color. Included only in the four-argument glColor4 commands. (With '4' colors only)

See Also: www.opengl.org/documentation/specs/man_pages/hardcopy/GL/html/gl/color.html