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Diffstat (limited to 'doc/python_api/examples/gpu.offscreen.1.py')
| -rw-r--r-- | doc/python_api/examples/gpu.offscreen.1.py | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/doc/python_api/examples/gpu.offscreen.1.py b/doc/python_api/examples/gpu.offscreen.1.py new file mode 100644 index 00000000000..06f0d915361 --- /dev/null +++ b/doc/python_api/examples/gpu.offscreen.1.py @@ -0,0 +1,192 @@ +# Draws an off-screen buffer and display it in the corner of the view. +import bpy +from bgl import * + + +class OffScreenDraw(bpy.types.Operator): + bl_idname = "view3d.offscreen_draw" + bl_label = "View3D Offscreen Draw" + + _handle_calc = None + _handle_draw = None + is_enabled = False + + # manage draw handler + @staticmethod + def draw_callback_px(self, context): + scene = context.scene + aspect_ratio = scene.render.resolution_x / scene.render.resolution_y + + self._update_offscreen(context, self._offscreen) + self._opengl_draw(context, self._texture, aspect_ratio, 0.2) + + @staticmethod + def handle_add(self, context): + OffScreenDraw._handle_draw = bpy.types.SpaceView3D.draw_handler_add( + self.draw_callback_px, (self, context), + 'WINDOW', 'POST_PIXEL', + ) + + @staticmethod + def handle_remove(): + if OffScreenDraw._handle_draw is not None: + bpy.types.SpaceView3D.draw_handler_remove(OffScreenDraw._handle_draw, 'WINDOW') + + OffScreenDraw._handle_draw = None + + # off-screen buffer + @staticmethod + def _setup_offscreen(context): + import gpu + scene = context.scene + aspect_ratio = scene.render.resolution_x / scene.render.resolution_y + + try: + offscreen = gpu.offscreen.new(512, int(512 / aspect_ratio)) + except Exception as e: + print(e) + offscreen = None + + return offscreen + + @staticmethod + def _update_offscreen(context, offscreen): + scene = context.scene + render = scene.render + camera = scene.camera + + modelview_matrix = camera.matrix_world.inverted() + projection_matrix = camera.calc_matrix_camera( + render.resolution_x, + render.resolution_y, + render.pixel_aspect_x, + render.pixel_aspect_y, + ) + + + offscreen.draw_view3d( + scene, + context.space_data, + context.region, + projection_matrix, + modelview_matrix, + ) + + @staticmethod + def _opengl_draw(context, texture, aspect_ratio, scale): + """ + OpenGL code to draw a rectangle in the viewport + """ + + glDisable(GL_DEPTH_TEST) + + # view setup + glMatrixMode(GL_PROJECTION) + glPushMatrix() + glLoadIdentity() + + glMatrixMode(GL_MODELVIEW) + glPushMatrix() + glLoadIdentity() + + glOrtho(-1, 1, -1, 1, -15, 15) + gluLookAt(0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0) + + act_tex = Buffer(GL_INT, 1) + glGetIntegerv(GL_TEXTURE_2D, act_tex) + + viewport = Buffer(GL_INT, 4) + glGetIntegerv(GL_VIEWPORT, viewport) + + width = int(scale * viewport[2]) + height = int(width / aspect_ratio) + + glViewport(viewport[0], viewport[1], width, height) + glScissor(viewport[0], viewport[1], width, height) + + # draw routine + glEnable(GL_TEXTURE_2D) + glActiveTexture(GL_TEXTURE0) + + glBindTexture(GL_TEXTURE_2D, texture) + + texco = [(1, 1), (0, 1), (0, 0), (1, 0)] + verco = [(1.0, 1.0), (-1.0, 1.0), (-1.0, -1.0), (1.0, -1.0)] + + glPolygonMode(GL_FRONT_AND_BACK, GL_FILL) + + glColor4f(1.0, 1.0, 1.0, 1.0) + + glBegin(GL_QUADS) + for i in range(4): + glTexCoord3f(texco[i][0], texco[i][1], 0.0) + glVertex2f(verco[i][0], verco[i][1]) + glEnd() + + # restoring settings + glBindTexture(GL_TEXTURE_2D, act_tex[0]) + + glDisable(GL_TEXTURE_2D) + + # reset view + glMatrixMode(GL_PROJECTION) + glPopMatrix() + + glMatrixMode(GL_MODELVIEW) + glPopMatrix() + + glViewport(viewport[0], viewport[1], viewport[2], viewport[3]) + glScissor(viewport[0], viewport[1], viewport[2], viewport[3]) + + # operator functions + @classmethod + def poll(cls, context): + return context.area.type == 'VIEW_3D' + + def modal(self, context, event): + if context.area: + context.area.tag_redraw() + + return {'PASS_THROUGH'} + + def invoke(self, context, event): + if OffScreenDraw.is_enabled: + self.cancel(context) + + return {'FINISHED'} + + else: + self._offscreen = OffScreenDraw._setup_offscreen(context) + if self._offscreen: + self._texture = self._offscreen.color_texture + else: + self.report({'ERROR'}, "Error initializing offscreen buffer. More details in the console") + return {'CANCELLED'} + + OffScreenDraw.handle_add(self, context) + OffScreenDraw.is_enabled = True + + if context.area: + context.area.tag_redraw() + + context.window_manager.modal_handler_add(self) + return {'RUNNING_MODAL'} + + def cancel(self, context): + OffScreenDraw.handle_remove() + OffScreenDraw.is_enabled = False + + if context.area: + context.area.tag_redraw() + + +def register(): + bpy.utils.register_class(OffScreenDraw) + + +def unregister(): + bpy.utils.unregister_class(OffScreenDraw) + + +if __name__ == "__main__": + register() |